c#读取下一条数据

longai123 2012-01-03 05:29:18

我记得以前delphi有个这个这样的导航控件.点一下邦定的texbox控件自动读取下一条记录

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longai123 2012-01-09

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搞出来了
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;
namespace WindowsApplication3
{
public partial class Form1 : Form
{
int i = 0;//i用来去顶其所在数据表的行号，一开始为第一行
DataSet ds;
SqlDataAdapter da;
string str = "Data Source=20111229-1228\\SQLEXPRESS;Initial Catalog=test;User ID=sa;Password=longhai";
string strsql = "select * from student";
SqlConnection cn;

public Form1()
{
InitializeComponent();
}

private void button8_Click(object sender, EventArgs e)
{
int k = 0;//用来确定要查找数据行的下标
if (textBox5.Text.Trim() == string.Empty)
{
MessageBox.Show("查找内容不能为空！");
textBox5.Focus();
}
else
for (k = 0; k < ds.Tables["student"].Rows.Count; k++)
if (ds.Tables["student"].Rows[k]["id"].ToString() == textBox5.Text) //找到textBox5.Text文本框中相匹配的数据行，其行号为k
{
i = k;
show(i);
break;
}
if (k == ds.Tables["student"].Rows.Count)
MessageBox.Show("无该学生信息");
textBox5.Text = "";

}
void show(int i)
{
try
{
if (ds != null)
ds.Clear();
else
{
ds = new DataSet();
da = new SqlDataAdapter(strsql, str);
}
//由于DataSet为断开连接的，因此在显示时对数据集重新填入，从而显示的为更新后的值
da.Fill(ds, "student");
DataRow dr = ds.Tables["student"].Rows[i];
textBox1.Text = dr["id"].ToString();
textBox2.Text = dr["name"].ToString();
textBox3.Text = dr["department"].ToString();
textBox4.Text = dr["age"].ToString();
}
catch(Exception ex)
{
MessageBox.Show(ex.Message);
}
}

private void Form1_Load(object sender, EventArgs e)
{
cn = new SqlConnection(str);
show(i);
}

private void button4_Click(object sender, EventArgs e)
{
i = 0;
show(i);
}

private void button1_Click(object sender, EventArgs e)
{
SqlConnection cn = new SqlConnection(str);
cn.Open();
SqlCommand Sqlcmd = new SqlCommand("select count(*) from student where id='" + textBox1.Text.Trim() + "'", cn);

// Sqlcmd.Connection.Open();
int a = (int)Sqlcmd.ExecuteScalar();//返回的为源表中与输入的学号相等的个数
Sqlcmd.Connection.Close();
if (a > 0)
{
MessageBox.Show("此学号已存在，请重新输入");
return;
}
//上述方法通过求出在student表中，输入的学号与表中的原有数据是否冲突
ds.Clear();
da.Fill(ds, "student");
ds.Tables["student"].PrimaryKey = new DataColumn[] { ds.Tables["student"].Columns["id"] };//设置数据表student 表的主码，为后来的使用Update 方法打下基础
SqlCommandBuilder sqlCommandBuilder1 = new SqlCommandBuilder(da); //通过 CommandBulider对象自动生成DbDataAdapter 的**Command属性
DataRow dr = ds.Tables["student"].NewRow();
dr["id"] = textBox1.Text;
dr["name"] = textBox2.Text;
dr["department"] = textBox3.Text;
if (textBox4.Text != "")
dr["age"] = int.Parse(textBox4.Text);
else
dr["age"] = 0;
ds.Tables["student"].Rows.Add(dr);
da.Update(ds, "student");
ds.AcceptChanges();
MessageBox.Show("数据插入成功");

}

private void button2_Click(object sender, EventArgs e)
{
for (int k = 0; k < ds.Tables["student"].Rows.Count; k++)
if (ds.Tables["student"].Rows[k]["id"].ToString() == "" + textBox1.Text + "" && ds.Tables["student"].Rows[k]["id"].ToString() != ds.Tables["student"].Rows[i]["id"].ToString())
{
MessageBox.Show("此学号已存在，请重新输入");
textBox1.Text = "";
return;
}
ds.Clear();
da.Fill(ds, "student");
ds.Tables["student"].PrimaryKey = new DataColumn[] { ds.Tables["student"].Columns["id"] };
SqlCommandBuilder sqlCommandBuilder1 = new SqlCommandBuilder(da);
ds.BeginInit();//挂起修改;
ds.Tables["student"].Rows[i]["id"] = textBox1.Text;
ds.Tables["student"].Rows[i]["name"] = textBox2.Text;
ds.Tables["student"].Rows[i]["department"] = textBox3.Text;
if (textBox4.Text != "")
ds.Tables["student"].Rows[i]["age"] = int.Parse(textBox4.Text);
else
ds.Tables["student"].Rows[i]["age"] = 0;
ds.EndInit();//终止挂起修改
da.Update(ds, "student");
ds.AcceptChanges();
MessageBox.Show("数据修改成功");
Refresh();

}

private void button3_Click(object sender, EventArgs e)
{
DataSet ds = new DataSet();
SqlDataAdapter da = new SqlDataAdapter(strsql, str);
da.Fill(ds, "student");
ds.Tables["student"].PrimaryKey = new DataColumn[] { ds.Tables["student"].Columns["id"] };
SqlCommandBuilder sqlCommandBuilder1 = new SqlCommandBuilder(da);
ds.Tables["student"].Rows[i].Delete();
da.Update(ds, "student");
ds.AcceptChanges();
MessageBox.Show("数据删除成功");
i = 0;
show(i);

}

private void button5_Click(object sender, EventArgs e)
{
if (i != 0)
{
i--;
show(i);
}
else
MessageBox.Show("已经是第一条记录");

}

private void button6_Click(object sender, EventArgs e)
{
if (i < ds.Tables["student"].Rows.Count - 1)
{
i++;
show(i);
}
else
MessageBox.Show("已经是最后一条记录");
}

private void button7_Click(object sender, EventArgs e)
{
i = ds.Tables["student"].Rows.Count - 1;
show(i);
}
}
}