怎么用JTextField的setText()方法显示数字.

nodreamer 2002-12-14 08:44:38
读取数据库后返回来的是int型数值,
result = statement.executeQuery(query);
result.next();
int out = result.getInt(1);
想在JTextField中显示,该怎么办??????

说详细点好吗?
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pengdali 2002-12-15
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result = statement.executeQuery(query);
result.next();
int out = result.getInt(1);
JTextField.setText(String.valueOf(out))
redkey 2002-12-15
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number.toString()
redkey 2002-12-15
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将数字转换成字符串进行显示
wolf7349 2002-12-14
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也可以用字符~
String temp;
char ch;
while(out>0)
{
ch=Character.forDigit(out%10,10);
out=out/10;
temp+=ch;
}
希偌 2002-12-14
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setText(out.toString());
yuwan 2002-12-14
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使用tf.setText("result:"+out);不行吗?
netwebs 2002-12-14
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将数字转化为字符串
String.valueOf(x)

x为数字
nodreamer 2002-12-14
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大家帮帮忙好吗?????????

能强制类型转换吗?

怎么转换????
import java.awt.*; import java.awt.event.*; import java.lang.*; import javax.swing.*; public class Counter extends Frame { //声明三个面板的布局 GridLayout gl1,gl2,gl3; Panel p0,p1,p2,p3; JTextField tf1; TextField tf2; Button b0,b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,b15,b16,b17,b18,b19,b20,b21,b22,b23,b24,b25,b26; StringBuffer str;//显示屏所显示的字符串 double x,y;//x和y都是运算数 int z;//Z表示单击了那一个运算符.0表示"+",1表示"-",2表示"*",3表示"/" static double m;//记忆的数字 public Counter() { gl1=new GridLayout(1,4,10,0);//实例化三个面板的布局 gl2=new GridLayout(4,1,0,15); gl3=new GridLayout(4,5,10,15); tf1=new JTextField(27);//显示屏 tf1.setHorizontalAlignment(JTextField.RIGHT); tf1.setEnabled(false); tf1.setText("0"); tf2=new TextField(10);//显示记忆的索引值 tf2.setEditable(false); //实例化所有按钮、设置其前景色并注册监听器 b0=new Button("Backspace"); b0.setForeground(Color.red); b0.addActionListener(new Bt()); b1=new Button("CE"); b1.setForeground(Color.red); b1.addActionListener(new Bt()); b2=new Button("C"); b2.setForeground(Color.red); b2.addActionListener(new Bt()); b3=new Button("MC"); b3.setForeground(Color.red); b3.addActionListener(new Bt()); b4=new Button("MR"); b4.setForeground(Color.red); b4.addActionListener(new Bt()); b5=new Button("MS"); b5.setForeground(Color.red); b5.addActionListener(new Bt()); b6=new Button("M+"); b6.setForeground(Color.red); b6.addActionListener(new Bt()); b7=new Button("7"); b7.setForeground(Color.blue); b7.addActionListener(new Bt()); b8=new Button("8"); b8.setForeground(Color.blue); b8.addActionListener(new Bt()); b9=new Button("9"); b9.setForeground(Color.blue); b9.addActionListener(new Bt()); b10=new Button("/"); b10.setForeground(Color.red); b10.addActionListener(new Bt()); b11=new Button("sqrt"); b11.setForeground(Color.blue); b11.addActionListener(new Bt()); b12=new Button("4"); b12.setForeground(Color.blue); b12.addActionListener(new Bt()); b13=new Button("5"); b13.setForeground(Color.blue); b13.addActionListener(new Bt()); b14=new Button("6"); b14.setForeground(Color.blue); b14.addActionListener(new Bt()); b15=new Button("*"); b15.setForeground(Color.red); b15.addActionListener(new Bt()); b16=new Button("%"); b16.setForeground(Color.blue); b16.addActionListener(new Bt()); b17=new Button("1"); b17.setForeground(Color.blue); b17.addActionListener(new Bt()); b18=new Button("2"); b18.setForeground(Color.blue); b18.addActionListener(new Bt()); b19=new Button("3"); b19.setForeground(Color.blue); b19.addActionListener(new Bt()); b20=new Button("-"); b20.setForeground(Color.red); b20.addActionListener(new Bt()); b21=new Button("1/X"); b21.setForeground(Color.blue); b21.addActionListener(new Bt()); b22=new Button("0"); b22.setForeground(Color.blue); b22.addActionListener(new Bt()); b23=new Button("+/-"); b23.setForeground(Color.blue); b23.addActionListener(new Bt()); b24=new Button("."); b24.setForeground(Color.blue); b24.addActionListener(new Bt()); b25=new Button("+"); b25.setForeground(Color.red); b25.addActionListener(new Bt()); b26=new Button("="); b26.setForeground(Color.red); b26.addActionListener(new Bt()); //实例化四个面板 p0=new Panel(); p1=new Panel(); p2=new Panel(); p3=new Panel(); //创建一个空字符串缓冲区 str=new StringBuffer(); //添加面板p0中的组件和设置其在框架中的位置和大小 p0.add(tf1); p0.setBounds(10,25,300,40); //添加面板p1中的组件和设置其在框架中的位置和大小 p1.setLayout(gl1); p1.add(tf2); p1.add(b0); p1.add(b1); p1.add(b2); p1.setBounds(10,65,300,25); //添加面板p2中的组件并设置其的框架中的位置和大小 p2.setLayout(gl2); p2.add(b3); p2.add(b4); p2.add(b5); p2.add(b6); p2.setBounds(10,110,40,150); //添加面板p3中的组件并设置其在框架中的位置和大小 p3.setLayout(gl3);//设置p3的布局 p3.add(b7); p3.add(b8); p3.add(b9); p3.add(b10); p3.add(b11); p3.add(b12); p3.add(b13); p3.add(b14); p3.add(b15); p3.add(b16); p3.add(b17); p3.add(b18); p3.add(b19); p3.add(b20); p3.add(b21); p3.add(b22); p3.add(b23); p3.add(b24); p3.add(b25); p3.add(b26); p3.setBounds(60,110,250,150); //设置框架中的布局为空布局并添加4个面板 setLayout(null); add(p0); add(p1); add(p2); add(p3); setResizable(false);//禁止调整框架的大小 //匿名类关闭窗口 addWindowListener(new WindowAdapter(){ public void windowClosing(WindowEvent e1) { System.exit(0); } }); setBackground(Color.lightGray); setBounds(100,100,320,280); setVisible(true); } //构造监听器 class Bt implements ActionListener { public void actionPerformed(ActionEvent e2) { try{ if(e2.getSource()==b1)//选择"CE"清零 { tf1.setText("0");//把显示屏清零 str.setLength(0);//清空字符串缓冲区以准备接收新的输入运算数 } else if(e2.getSource()==b2)//选择"C"清零 { tf1.setText("0");//把显示屏清零 str.setLength(0); } else if(e2.getSource()==b23)//单击"+/-"选择输入的运算数是正数还是负数 { x=Double.parseDouble(tf1.getText().trim()); tf1.setText(""+(-x)); } else if(e2.getSource()==b25)//单击加号按钮获得x的值和z的值并清空y的值 { x=Double.parseDouble(tf1.getText().trim()); str.setLength(0);//清空缓冲区以便接收新的另一个运算数 y=0d; z=0; } else if(e2.getSource()==b20)//单击减号按钮获得x的值和z的值并清空y的值 { x=Double.parseDouble(tf1.getText().trim()); str.setLength(0); y=0d; z=1; } else if(e2.getSource()==b15)//单击乘号按钮获得x的值和z的值并清空y的值 { x=Double.parseDouble(tf1.getText().trim()); str.setLength(0); y=0d; z=2; } else if(e2.getSource()==b10)//单击除号按钮获得x的值和z的值并空y的值 { x=Double.parseDouble(tf1.getText().trim()); str.setLength(0); y=0d; z=3; } else if(e2.getSource()==b26)//单击等号按钮输出计算结果 { str.setLength(0); switch(z) { case 0 : tf1.setText(""+(x+y));break; case 1 : tf1.setText(""+(x-y));break; case 2 : tf1.setText(""+(x*y));break; case 3 : tf1.setText(""+(x/y));break; } } else if(e2.getSource()==b24)//单击"."按钮输入小数 { if(tf1.getText().trim().indexOf(′.′)!=-1)//判断字符串中是否已经包含了小数点 { } else//如果没数点有小 { if(tf1.getText().trim().equals("0"))//如果初时显示为0 { str.setLength(0); tf1.setText((str.append("0"+e2.getActionCommand())).toString()); } else if(tf1.getText().trim().equals(""))//如果初时显示为空则不做任何操作 { } else { tf1.setText(str.append(e2.getActionCommand()).toString()); } } y=0d; } else if(e2.getSource()==b11)//求平方根 { x=Double.parseDouble(tf1.getText().trim()); tf1.setText("数字格式异常"); if(x<0) tf1.setText("负数没有平方根"); else tf1.setText(""+Math.sqrt(x)); str.setLength(0); y=0d; } else if(e2.getSource()==b16)//单击了"%"按钮 { x=Double.parseDouble(tf1.getText().trim()); tf1.setText(""+(0.01*x)); str.setLength(0); y=0d; } else if(e2.getSource()==b21)//单击了"1/X"按钮 { x=Double.parseDouble(tf1.getText().trim()); if(x==0) { tf1.setText("除数不能为零"); } else { tf1.setText(""+(1/x)); } str.setLength(0); y=0d; } else if(e2.getSource()==b3)//MC为清除内存 { m=0d; tf2.setText(""); str.setLength(0); } else if(e2.getSource()==b4)//MR为重新调用存储的数据 { if(tf2.getText().trim()!="")//有记忆数字 { tf1.setText(""+m); } } else if(e2.getSource()==b5)//MS为存储显示的数据 { m=Double.parseDouble(tf1.getText().trim()); tf2.setText("M"); tf1.setText("0"); str.setLength(0); } else if(e2.getSource()==b6)//M+为将显示数字与已经存储的数据相加要查看新的数字单击MR { m=m+Double.parseDouble(tf1.getText().trim()); } else//选择的是其他的按钮 { if(e2.getSource()==b22)//如果选择的是"0"这个数字键 { if(tf1.getText().trim().equals("0"))//如果显示显示的为零不做操作 { } else { tf1.setText(str.append(e2.getActionCommand()).toString()); y=Double.parseDouble(tf1.getText().trim()); } } else if(e2.getSource()==b0)//选择的是“BackSpace”按钮 { if(!tf1.getText().trim().equals("0"))//如果显示显示的不是零 { if(str.length()!=1) { tf1.setText(str.delete(str.length()-1,str.length()).toString());//可能抛出字符串越界异常 } else { tf1.setText("0"); str.setLength(0); } } y=Double.parseDouble(tf1.getText().trim()); } else//其他的数字键 { tf1.setText(str.append(e2.getActionCommand()).toString()); y=Double.parseDouble(tf1.getText().trim()); } } } catch(NumberFormatException e){ tf1.setText("数字格式异常"); } catch(StringIndexOutOfBoundsException e){ tf1.setText("字符串索引越界"); } } } public static void main(String args[]) { new Counter(); } }
/****************************************** * Made by : ff * QQ : 394447974 * E_Mail : xysyclover@163.com * http://tech.cuit.edu.cn * 2007-12-01 21:45 * 简单计算器 Test V1.0 *******************************************/ import java.awt.*; import java.lang.*; import javax.swing.*; import javax.swing.event.*; import java.awt.event.*; import java.text.DecimalFormat; public class Calculator implements ActionListener { //导入动作监听接口 //设计面板中的单位 JFrame frame;//主窗口 JTextField textAnswer;//显示文本框 JPanel panel, panel1, panel2, panel3; JMenuBar mainMenu; JTextField textMemory; JLabel labelMemSpace; //labelMemSpace单纯做摆设,控制面板的形状 JButton buttonBk, buttonCe, buttonC; JButton button[]; JButton buttonMC, buttonMR, buttonMS, buttonMAdd; JButton buttonDot, buttonAddAndSub, buttonAdd, buttonSub, buttonMul, buttonDiv, buttonMod; JButton buttonSqrt, buttonDao, buttonEqual; JMenu viewMenu, helpMenu; JMenuItem tItem, sItem, topHelp, aboutCal; DecimalFormat df; //设置数据输出精度 boolean clickable; //控制当前能否按键 double memoryd; //使用内存中存储的数字 int memoryi; double vard, answerd; //用来保存double型数据的中间值(vard)和最后结果(answerd) short key = -1, prekey = -1; //key用来保存当前进行何种运算,prekey用来保存前次进行何种运算 String copy; //做复制用 JTextArea help; //帮助 JScrollPane scrollHelp; //构造函数 public Calculator() { clickable = true; answerd = 0; frame = new JFrame("计算器 Test--V1.0 Made by:ff"); df = new DecimalFormat("0.00000000"); //设置数据输出精度(对于double型值) textAnswer = new JTextField(15); textAnswer.setText(""); textAnswer.setHorizontalAlignment(JTextField.RIGHT); textAnswer.setBorder(BorderFactory.createLineBorder(Color.red)); textAnswer.setEditable(false); textAnswer.setBackground(new Color(255, 255, 255)); panel = new JPanel(); frame.getContentPane().add(panel); panel1 = new JPanel(); panel2 = new JPanel(); panel.setLayout(new BorderLayout()); //设计整个面板 mainMenu = new JMenuBar(); viewMenu = new JMenu("查看(V)"); helpMenu = new JMenu("帮助(H)"); tItem = new JMenuItem("●标准型(T)"); tItem.addActionListener(this); sItem = new JMenuItem("●科学型(S)"); sItem.addActionListener(this); viewMenu.add(tItem); viewMenu.add(sItem); topHelp = new JMenuItem(" 帮助主题(H)"); topHelp.addActionListener(this); help = new JTextArea(5, 20); scrollHelp = new JScrollPane(help); help.setEditable(false); help.append("执行简单计算\n"); help.append("1. 键入计算的第一个数字。\n"); help.append("2. 单击“+”执行加、“-”执行减、“*”执行乘或“/”执行除。\n"); help.append("3. 键入计算的下一个数字。\n"); help.append("4. 输入所有剩余的运算符和数字。\n"); help.append("5. 单击“=”。\n"); aboutCal = new JMenuItem(" 关于计算器(A)"); aboutCal.addActionListener(this); helpMenu.add(topHelp); helpMenu.add(aboutCal); mainMenu.add(viewMenu); mainMenu.add(helpMenu); panel.add(mainMenu, BorderLayout.NORTH); panel.add(textAnswer, BorderLayout.CENTER); panel.add(panel1, BorderLayout.SOUTH); panel1.setLayout(new BorderLayout()); textMemory = new JTextField(3); textMemory.setEditable(false); textMemory.setBackground(new Color(217, 217, 217)); labelMemSpace = new JLabel(" "); buttonBk = new JButton("Backspace"); buttonBk.setForeground(new Color(255, 0, 0)); buttonCe = new JButton("CE"); buttonCe.setForeground(new Color(255, 0, 0)); buttonC = new JButton("C"); buttonC.setForeground(new Color(255, 0, 0)); buttonBk.addActionListener(this); buttonCe.addActionListener(this); buttonC.addActionListener(this); panel1.add(panel2, BorderLayout.NORTH); panel2.setLayout(new FlowLayout(FlowLayout.RIGHT)); panel2.add(textMemory); panel2.add(labelMemSpace); panel2.add(buttonBk); panel2.add(buttonCe); panel2.add(buttonC); panel3 = new JPanel(); panel1.add(panel3, BorderLayout.CENTER); button = new JButton[10]; for (int i = 0; i < button.length; i++) { button[i] = new JButton(Integer.toString(i)); button[i].setForeground(new Color(0, 0, 255)); } buttonMC = new JButton("MC"); buttonMC.setForeground(new Color(255, 0, 0)); buttonMR = new JButton("MR"); buttonMR.setForeground(new Color(255, 0, 0)); buttonMS = new JButton("MS"); buttonMS.setForeground(new Color(255, 0, 0)); buttonMAdd = new JButton("M+"); buttonMAdd.setForeground(new Color(255, 0, 0)); buttonDot = new JButton("."); buttonDot.setForeground(new Color(0, 0, 255)); buttonAddAndSub = new JButton("+/-"); buttonAddAndSub.setForeground(new Color(0, 0, 255)); buttonAdd = new JButton("+"); buttonAdd.setForeground(new Color(255, 0, 0)); buttonSub = new JButton("-"); buttonSub.setForeground(new Color(255, 0, 0)); buttonMul = new JButton("*"); buttonMul.setForeground(new Color(255, 0, 0)); buttonDiv = new JButton("/"); buttonDiv.setForeground(new Color(255, 0, 0)); buttonMod = new JButton("%"); buttonMod.setForeground(new Color(0, 0, 255)); buttonSqrt = new JButton("sqrt"); buttonSqrt.setForeground(new Color(0, 0, 255)); buttonDao = new JButton("1/x"); buttonDao.setForeground(new Color(0, 0, 255)); buttonEqual = new JButton("="); buttonEqual.setForeground(new Color(255, 0, 0)); //将所有行为与监听绑定 panel3.setLayout(new GridLayout(4, 6)); panel3.add(buttonMC); buttonMC.addActionListener(this); panel3.add(button[7]); button[7].addActionListener(this); panel3.add(button[8]); button[8].addActionListener(this); panel3.add(button[9]); button[9].addActionListener(this); panel3.add(buttonDiv); buttonDiv.addActionListener(this); panel3.add(buttonSqrt); buttonSqrt.addActionListener(this); panel3.add(buttonMR); buttonMR.addActionListener(this); panel3.add(button[4]); button[4].addActionListener(this); panel3.add(button[5]); button[5].addActionListener(this); panel3.add(button[6]); button[6].addActionListener(this); panel3.add(buttonMul); buttonMul.addActionListener(this); panel3.add(buttonMod); buttonMod.addActionListener(this); panel3.add(buttonMS); buttonMS.addActionListener(this); panel3.add(button[1]); button[1].addActionListener(this); panel3.add(button[2]); button[2].addActionListener(this); panel3.add(button[3]); button[3].addActionListener(this); panel3.add(buttonSub); buttonSub.addActionListener(this); panel3.add(buttonDao); buttonDao.addActionListener(this); panel3.add(buttonMAdd); buttonMAdd.addActionListener(this); panel3.add(button[0]); button[0].addActionListener(this); panel3.add(buttonAddAndSub); buttonAddAndSub.addActionListener(this); panel3.add(buttonDot); buttonDot.addActionListener(this); panel3.add(buttonAdd); buttonAdd.addActionListener(this); panel3.add(buttonEqual); buttonEqual.addActionListener(this); frame.setDefaultCloseOperation(frame.EXIT_ON_CLOSE); frame.pack(); frame.show(); } //设置各个按钮行为 public void actionPerformed(ActionEvent event) { boolean sign = false; //判断是否是double型数参与运算,是为true,不是为false Object temp = event.getSource(); try { //如果按下数据按钮,将按下的按钮代表的数据插入的当前文本框字符串之后 for (int i = 0; i <= 9; i++) if (temp == button[i] && clickable == true) textAnswer.setText(textAnswer.getText() + Integer.toString(i)); //按下'.'按钮时,判断当前文本框内字符串中含不含'.',如果已含,则不允许再插入'.' if (temp == buttonDot && clickable == true) { boolean isDot = false; if (textAnswer.getText().length() == 0) isDot = true; for (int i = 0; i < textAnswer.getText().length(); i++) if ('.' == textAnswer.getText().charAt(i)) { isDot = true; break; } if (isDot == false) textAnswer.setText(textAnswer.getText() + "."); } if ( (temp == buttonAdd || temp == buttonSub || temp == buttonMul || temp == buttonDiv) && clickable == true) { //'+'操作 if (temp == buttonAdd) { switch (prekey) { case 0: answerd += Double.parseDouble(textAnswer.getText()); break; case 1: answerd -= Double.parseDouble(textAnswer.getText()); break; case 2: answerd *= Double.parseDouble(textAnswer.getText()); break; case 3: if (Double.parseDouble(textAnswer.getText()) == 0) { textAnswer.setText("除数不能为零"); clickable = false; } else answerd /= Double.parseDouble(textAnswer.getText()); break; default: answerd = Double.parseDouble(textAnswer.getText()); } textAnswer.setText(""); prekey = key = 0; } //'-'操作 if (temp == buttonSub) { switch (prekey) { case 0: answerd += Double.parseDouble(textAnswer.getText()); break; case 1: answerd -= Double.parseDouble(textAnswer.getText()); break; case 2: answerd *= Double.parseDouble(textAnswer.getText()); break; case 3: if (Double.parseDouble(textAnswer.getText()) == 0) { textAnswer.setText("除数不能为零"); clickable = false; } else answerd /= Double.parseDouble(textAnswer.getText()); break; default: answerd = Double.parseDouble(textAnswer.getText()); } textAnswer.setText(""); prekey = key = 1; } //'*'操作 if (temp == buttonMul) { switch (prekey) { case 0: answerd += Double.parseDouble(textAnswer.getText()); break; case 1: answerd -= Double.parseDouble(textAnswer.getText()); break; case 2: answerd *= Double.parseDouble(textAnswer.getText()); break; case 3: if (Double.parseDouble(textAnswer.getText()) == 0) { textAnswer.setText("除数不能为零"); clickable = false; } else answerd /= Double.parseDouble(textAnswer.getText()); break; default: answerd = Double.parseDouble(textAnswer.getText()); } textAnswer.setText(""); prekey = key = 2; } //'/'操作 if (temp == buttonDiv) { switch (prekey) { case 0: answerd += Double.parseDouble(textAnswer.getText()); break; case 1: answerd -= Double.parseDouble(textAnswer.getText()); break; case 2: answerd *= Double.parseDouble(textAnswer.getText()); break; case 3: if (Double.parseDouble(textAnswer.getText()) == 0) { textAnswer.setText("除数不能为零"); clickable = false; } else answerd /= Double.parseDouble(textAnswer.getText()); break; default: answerd = Double.parseDouble(textAnswer.getText()); } textAnswer.setText(""); prekey = key = 3; } } //'='操作 if (temp == buttonEqual && clickable == true) { //如果连续按'=',则进行连续运算 if (prekey == 5) { if (key == 0) { answerd += vard; textAnswer.setText(df.format(answerd)); } if (key == 1) { answerd -= vard; textAnswer.setText(df.format(answerd)); } if (key == 2) { answerd *= vard; textAnswer.setText(df.format(answerd)); } if (key == 3) { if (Double.parseDouble(textAnswer.getText()) == 0) { textAnswer.setText("除数不能为零"); clickable = false; } else { answerd /= vard; textAnswer.setText(df.format(answerd)); } } } else { vard = Double.parseDouble(textAnswer.getText()); if (key == 0) { prekey = -1; answerd += Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); } if (key == 1) { prekey = -1; answerd -= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); } if (key == 2) { prekey = -1; answerd *= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); } if (key == 3) { prekey = -1; if (Double.parseDouble(textAnswer.getText()) == 0) { textAnswer.setText("除数不能为零"); clickable = false; } else { answerd /= Double.parseDouble(textAnswer.getText()); textAnswer.setText(df.format(answerd)); } } } prekey = 5; } //'%'操作,对第二个操作数除以100 if (temp == buttonMod && clickable == true) { if (answerd == 0) { String s = textAnswer.getText(); textAnswer.setText(s); } else { boolean isDot = false; for (int i = 0; i < textAnswer.getText().length(); i++) if ('.' == textAnswer.getText().charAt(i)) { isDot = true; break; } //如果是double数,除100 if (isDot == true) { double dtemp = Double.parseDouble(textAnswer.getText()); dtemp = dtemp / 100.0; textAnswer.setText(Double.toString(dtemp)); } else { //如果是int数但能被100整除,则去掉末尾两个零 if (Integer.parseInt(textAnswer.getText()) % 100 == 0) { int itemp = Integer.parseInt(textAnswer.getText()); itemp /= 100; textAnswer.setText(Integer.toString(itemp)); } //如果是int数,但不能被100整除,则按double数处理 else { double dtemp = Double.parseDouble(textAnswer.getText()); dtemp = dtemp / 100.0; textAnswer.setText(Double.toString(dtemp)); } } } } //开根号运算 if (temp == buttonSqrt && clickable == true) { String s = textAnswer.getText(); if (s.charAt(0) == '-') { textAnswer.setText("负数不能开根号"); clickable = false; } else textAnswer.setText(Double.toString(java.lang.Math.sqrt(Double. parseDouble(textAnswer.getText())))); } //倒数运算 if (temp == buttonDao && clickable == true) { if (textAnswer.getText().charAt(0) == '0' && textAnswer.getText().length() == 1) { textAnswer.setText("零不能求倒数"); clickable = false; } else { boolean isDec = true; int i, j, k; String s = Double.toString(1 / Double.parseDouble(textAnswer.getText())); for (i = 0; i < s.length(); i++) if (s.charAt(i) == '.') break; for (j = i + 1; j < s.length(); j++) if (s.charAt(j) != '0') { isDec = false; break; } if (isDec == true) { String stemp = ""; for (k = 0; k < i; k++) stemp += s.charAt(k); textAnswer.setText(stemp); } else textAnswer.setText(s); } } //按下'+/-'按钮时处理 if (temp == buttonAddAndSub && clickable == true) { boolean isNumber = true; String s = textAnswer.getText(); for (int i = 0; i < s.length(); i++) if (! (s.charAt(i) >= '0' && s.charAt(i) <= '9' || s.charAt(i) == '.' || s.charAt(i) == '-')) { isNumber = false; break; } if (isNumber == true) { //如果当前字符串首字母有'-'号,代表现在是个负数,再按下时,则将首符号去掉 if (s.charAt(0) == '-') { textAnswer.setText(""); for (int i = 1; i < s.length(); i++) { char a = s.charAt(i); textAnswer.setText(textAnswer.getText() + a); } } //如果当前字符串第一个字符不是符号,则添加一个符号在首字母处 else textAnswer.setText('-' + s); } } //计算器有关内存操作 //'MC'的操作,将内存清0 if (temp == buttonMC && clickable == true) { memoryd = memoryi = 0; textMemory.setText(""); } //'MS'的操作,将当前文本框内容保存入内存,显示'M' if (temp == buttonMS && clickable == true) { boolean isDot = false; textMemory.setText(" M"); for (int i = 0; i < textAnswer.getText().length(); i++) if ('.' == textAnswer.getText().charAt(i)) { isDot = true; break; } //如果是double,则存入memoryd(double存储器) if (isDot == true) { memoryd = Double.parseDouble(textAnswer.getText()); memoryi = 0; //保证存储器中存放最新的值 } //如果是int,则存入memoryi(int存储器) else { memoryi = Integer.parseInt(textAnswer.getText()); memoryd = 0; //保证存储器中存放最新的值 } } //'MR'的操作,将存储器中的信息输出 if (temp == buttonMR && clickable == true) { if (memoryd != 0) textAnswer.setText(Double.toString(memoryd)); if (memoryi != 0) textAnswer.setText(Integer.toString(memoryi)); } //'M+'的功能,将当前文本框里的数据和存储器中数据相加后,再存入存储器 if (temp == buttonMAdd && clickable == true) { boolean isDot = false; for (int i = 0; i < textAnswer.getText().length(); i++) if ('.' == textAnswer.getText().charAt(i)) { isDot = true; break; } if (memoryi != 0) { //存储中是一个int型数 if (isDot == false) //被加数是一个int型数 memoryi += Integer.parseInt(textAnswer.getText()); else { //被加数是一个double型数,则将int存储器中数传入double存储器与当前数相加,int存储器清零 memoryd = memoryi + Double.parseDouble(textAnswer.getText()); memoryi = 0; } } else memoryd += Double.parseDouble(textAnswer.getText()); } //按下'Backspace'键,利用循环将当前字符串中的最后一个字母删除 if (temp == buttonBk && clickable == true) { String s = textAnswer.getText(); textAnswer.setText(""); for (int i = 0; i < s.length() - 1; i++) { char a = s.charAt(i); textAnswer.setText(textAnswer.getText() + a); } } //按下'CE'按钮,将当前文本框内数据清除 if (temp == buttonCe) { textAnswer.setText(""); clickable = true; } //按下'C'按钮,文本框内数据清除,同时var,answer清0 if (temp == buttonC) { vard = answerd = 0; textAnswer.setText(""); clickable = true; } if (temp == sItem) { JOptionPane.showMessageDialog(panel, "当前是标准型计算器,\n科学型计算器有待更新。"); } //按下'帮助主题'菜单栏 if (temp == topHelp) { JOptionPane.showMessageDialog(panel, scrollHelp); } //按下'关于'菜单栏 if (temp == aboutCal) { JOptionPane.showMessageDialog(panel, "开发者:ff \n QQ :394447974 \n E_mail:xysyclover@163.com"); } } //输入中如果有操作非法,比如按下两次'+',捕获异常 catch (Exception e) { textAnswer.setText("操作非法"); clickable = false; } } //主函数 public static void main(String args[]) { new Calculator(); } }
java编写的计算器,能实现加减乘除。 //***该梦幻计算器与Windows附件自带计算器的标准版功能、界面相仿***// //******但还不支持键盘操作,如有需要,下一次等级将满足你**********// import java.awt.*; import java.lang.*; import javax.swing.*; import javax.swing.event.*; import java.awt.event.*; import java.awt.Component.*; import java.awt.color.*; import java.text.DecimalFormat; //*****************************************************************************// //*****************************************************************************// public class Calculator implements ActionListener //导入动作监听接口 { //******************************// //*****设计计算器界面的单位*****// JFrame frame; //定义框架 JTextField textAnswer; //定义输出显示框 JPanel panel, panel1, panel2, panel3;//定义面板作为子容器,从而达到要求的界面效果 JMenuBar mainMenu; JTextField textMemory; JLabel labelMemSpace; //labelMemSpace单纯做摆设,控制面板的形状 JButton buttonBk, buttonCe, buttonC; JButton button[]; JButton buttonMC, buttonMR, buttonMS, buttonMAdd; JButton buttonDot, buttonAddAndSub, buttonAdd, buttonSub, buttonMul,buttonDiv, buttonMod; JButton buttonSqrt, buttonDao, buttonEqual; JMenu editMenu, viewMenu, helpMenu; JMenuItem copyItem, pasteItem, tItem, sItem, numberGroup, topHelp, aboutCal,myCollege; DecimalFormat df; //设置数据输出精度 boolean clickable; //控制当前能否按键 double memoryd; //使用内存中存储的数字 int memoryi; double vard, answerd; //用来保存double型数据的中间值(vard)和最后结果(answerd) short key = -1, prekey = -1; //key用来保存当前进行何种运算,prekey用来保存前次进行何种运算 boolean clear = false; String copy; //做复制用 JTextArea help; //帮助 JScrollPane scrollHelp; static boolean One =true; //******************// //*****构造函数开始*****// public Calculator() { clickable = true; answerd = 0; frame = new JFrame("梦幻计算器--SWE08008"); frame.setResizable(false);//不允许改变计算器的大小 frame.setLocation(250,150);//设置计算器的起始位置 frame.setBackground(Color.YELLOW); df = new DecimalFormat("0.##############"); //设置数据输出精度(对于double型值)
package chapter11_3; import java.awt.BorderLayout; import java.awt.Color; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.ImageIcon; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JOptionPane; import javax.swing.JPanel; import javax.swing.JTextField; public class Calculator extends JFrame implements ActionListener { private String[] str = { "7", "8", "9", "/", "sqrt", "4", "5", "6", "*", "%", "1", "2", "3", "-", "1/x", "0", "+/-", ".", "+", "=" }; private JTextField tf_out; private JButton jb_bk, jb_ce, jb_c; private JButton[] jb_key; private char ch = '#'; private boolean can = false; private double num1; public void creatGUI() { tf_out = new JTextField(); tf_out.setHorizontalAlignment(JTextField.RIGHT); tf_out.setColumns(18); tf_out.setEditable(false); // 设置输出不可编辑 tf_out.setText("0"); this.add(tf_out, BorderLayout.NORTH); JPanel p = new JPanel(new BorderLayout(3, 8)); JPanel p1 = new JPanel(new GridLayout(1, 3, 3, 10)); p.add(p1, "North"); jb_bk = new JButton("Backspace"); jb_bk.setForeground(Color.RED); jb_bk.addActionListener(this); jb_ce = new JButton("CE"); jb_ce.setForeground(Color.RED); jb_ce.addActionListener(this); jb_c = new JButton("C"); jb_c.setForeground(Color.RED); jb_c.addActionListener(this); p1.add(jb_bk); p1.add(jb_ce); p1.add(jb_c); JPanel p2 = new JPanel(new GridLayout(4, 5, 3, 3)); p.add(p2, BorderLayout.CENTER); jb_key = new JButton[str.length]; for (int i = 0; i < str.length; i++) { jb_key[i] = new JButton(str[i]); jb_key[i].addActionListener(this); if (i == 3 || i == 8 || i == 13 || i == 18 || i == 19) { jb_key[i].setForeground(Color.RED); } else { jb_key[i].setForeground(Color.BLUE); } p2.add(jb_key[i]); } this.add(p, BorderLayout.CENTER); this.setTitle("计算器"); this.setIconImage(new ImageIcon("image/1.jpg").getImage()
import java.awt.*; import java.awt.event.*; import javax.swing.*; public class Text extends JFrame implements ActionListener,TextListener { private JLabel username,password,email,telephone; private JTextField usernameField,emailField; private TextField teleField; private JPasswordField passwordField; private JButton registButton,cancelButton; public Text() { super("用户注册"); Container container = getContentPane(); container.setLayout(new FlowLayout()); username = new JLabel("用户名"); username.setToolTipText("请输入用户名"); password = new JLabel("密 码"); password.setToolTipText("密码不能少于6位"); email = new JLabel("邮 箱"); email.setToolTipText("邮箱中必须包含@字符"); telephone = new JLabel("电 话"); telephone.setToolTipText("电话只能为数字"); usernameField = new JTextField(15); usernameField.addActionListener(this); passwordField = new JPasswordField(15); passwordField.addActionListener(this); emailField = new JTextField(15); emailField.addActionListener(this); teleField = new TextField(21); teleField.addActionListener(this); teleField.addTextListener(this); registButton = new JButton("注册"); cancelButton = new JButton("取消"); container.add(username); container.add(usernameField); container.add(password); container.add(passwordField); container.add(email); container.add(emailField); container.add(telephone); container.add(teleField); container.add(registButton); container.add(cancelButton); registButton.addActionListener(this); cancelButton.addActionListener(this); setSize(250,200); setVisible(true); setResizable(false); } public void textValueChanged(TextEvent event) { if (event.getSource() == teleField) { /*if (!checkNumber(teleField.getText())) { JOptionPane.showMessageDialog(this,"电话必须为数字","温馨提示",JOptionPane.INFORMATION_MESSAGE); teleField.setText(""); } */ } } public void actionPerformed(ActionEvent event) { if (event.getSource() == usernameField) { if (usernameField.getText().equals("")) { JOptionPane.showMessageDialog(null,"用户名不能为空","温馨提示",JOptionPane.INFORMATION_MESSAGE); } } if (event.getSource() == passwordField) { if (passwordField.getPassword().length == 0) { JOptionPane.showMessageDialog(this,"密码不能为空","温馨提示",JOptionPane.INFORMATION_MESSAGE); } else if (passwordField.getPassword().length < 6) { JOptionPane.showMessageDialog(this,"密码长度不能小于6位","温馨提示",JOptionPane.INFORMATION_MESSAGE); passwordField.setText(""); } } if (event.getSource() == emailField) { if (emailField.getText().indexOf("@") < 0 || emailField.getText().indexOf("@") >= (emailField.getText().length() - 1) || emailField.getText().equals("")) { JOptionPane.showMessageDialog(this,"您的邮箱格式不正确","温馨提示",JOptionPane.INFORMATION_MESSAGE); emailField.setText(""); } } if (event.getSource() == teleField) { if (teleField.getText().equals("")) { JOptionPane.showMessageDialog(this,"联系电话不能为空","温馨提示",JOptionPane.INFORMATION_MESSAGE); } else if (!checkNumber(teleField.getText())) { JOptionPane.showMessageDialog(this,"电话必须为数字","温馨提示",JOptionPane.INFORMATION_MESSAGE); teleField.setText(""); } } if (event.getSource() == registButton) { if (usernameField.getText().equals("") || passwordField.getPassword().length == 0 || emailField.getText().equals("") || teleField.getText().equals("")) { JOptionPane.showMessageDialog(this, "您填写的信息不完整","温馨提示",JOptionPane.INFORMATION_MESSAGE); usernameField.setText(""); passwordField.setText(""); emailField.setText(""); teleField.setText(""); } else if (passwordField.getPassword().length < 6) { JOptionPane.showMessageDialog(this,"密码长度不能小于6位","温馨提示",JOptionPane.INFORMATION_MESSAGE); passwordField.setText(""); } else if (emailField.getText().indexOf("@") < 0 || emailField.getText().indexOf("@") >= (emailField.getText().length() - 1)) { JOptionPane.showMessageDialog(this,"您的邮箱格式不正确","温馨提示",JOptionPane.INFORMATION_MESSAGE); emailField.setText(""); } else if (!checkNumber(teleField.getText())) { JOptionPane.showMessageDialog(this,"电话必须为数字","温馨提示",JOptionPane.INFORMATION_MESSAGE); teleField.setText(""); } else JOptionPane.showMessageDialog(this,"恭喜您,注册成功","温馨提示",JOptionPane.INFORMATION_MESSAGE); } if (event.getSource() == cancelButton) { usernameField.setText(""); passwordField.setText(""); emailField.setText(""); teleField.setText(""); } } public boolean checkNumber(String str) { for (int i=0;i

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