JFrame在去掉标题栏的情况下怎么实现拉大收缩边框的功能？

[yaochunpin]

JFrame在去掉标题栏的情况下怎么实现拉大收缩边框的功能？谢谢！

[yaochunpin]

呀，没人回答啊，自己顶一下！

[Tassdars]

只能自己实现了，思路是把JFrame分成九个区域，八个boolean状态变量，当然，是虚拟的划分，注册mouse move事件，当鼠标进入不同区域的时候设置八个boolean状态变量的值，同时改变鼠标指针状态，然后注册mouse down事件，根据八个boolean状态变量的值确定应该如何Resize，还是比较复杂的。

[Tassdars]

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class ResizeFrame extends JFrame {
	private boolean isTopLeft;
	private boolean isTop;
	private boolean isTopRight;
	private boolean isRight;
	private boolean isBottomRight;
	private boolean isBottom;
	private boolean isBottomLeft;
	private boolean isLeft;
	private final static int RESIZE_WIDTH = 5;
	private final static int MIN_WIDTH = 20;
	private final static int MIN_HEIGHT = 20;
	
	public ResizeFrame() {
		addMouseMotionListener(new ResizeAdapter(this));
	}
	
	private class ResizeAdapter extends MouseAdapter {
		private Component c;
		
		public ResizeAdapter(Component c) {
			this.c = c;
		}
		
		@Override
		public void mouseMoved(MouseEvent event) {
			int x = event.getX();
			int y = event.getY();
			int width = c.getWidth();
			int height = c.getHeight();
			int cursorType = Cursor.DEFAULT_CURSOR;
			isTopLeft = isTop = isTopRight = isRight = isBottomRight = isBottom = isBottomLeft = isLeft = false;
			if (y <= RESIZE_WIDTH) {
				if (x <= RESIZE_WIDTH) {
					isTopLeft = true;
					cursorType = Cursor.NW_RESIZE_CURSOR;
				} else if (x >= width - RESIZE_WIDTH) {
					isTopRight = true;
					cursorType = Cursor.NE_RESIZE_CURSOR;
				} else {
					isTop = true;
					cursorType = Cursor.N_RESIZE_CURSOR;
				}
			} else if (y >= height - RESIZE_WIDTH) {
				if (x <= RESIZE_WIDTH) {
					isBottomLeft = true;
					cursorType = Cursor.SW_RESIZE_CURSOR;
				} else if (x >= width - RESIZE_WIDTH) {
					isBottomRight = true;
					cursorType = Cursor.SE_RESIZE_CURSOR;
				} else {
					isBottom = true;
					cursorType = Cursor.S_RESIZE_CURSOR;
				}
			} else if (x <= RESIZE_WIDTH) {
				isLeft = true;
				cursorType = Cursor.W_RESIZE_CURSOR;
			} else if (x >= width - RESIZE_WIDTH) {
				isRight = true;
				cursorType = Cursor.E_RESIZE_CURSOR;
			}
			c.setCursor(new Cursor(cursorType));
		}
		
		@Override
		public void mouseDragged(MouseEvent event) {
			int x = event.getX();
			int y = event.getY();
			int width = c.getWidth();
			int height = c.getHeight();
			if (isTopLeft) {
				c.setLocation(c.getX() + x, c.getY() + y);
				c.setSize(width - x, height - y);
			}
			if (isTop) {
				c.setLocation(c.getX(), c.getY() + y);
				c.setSize(width, height - y);
			}
			if (isTopRight) {
				c.setLocation(c.getX(), c.getY() + y);
				c.setSize(x, height - y);
			}
			if (isRight) {
				c.setSize(x, height);
			}
			if (isBottomRight) {
				c.setSize(x, y);
			}
			if (isBottom) {
				c.setSize(width, y);
			}
			if (isBottomLeft) {
				c.setLocation(c.getX() + x, c.getY());
				c.setSize(width - x, y);
			}
			if (isLeft) {
				c.setLocation(c.getX() + x, c.getY());
				c.setSize(width - x, height);
			}
		}
	}
	
	public static void main(String[] args) {
		JFrame frame = new ResizeFrame();
		frame.setLocation(200, 200);
		frame.setSize(400, 300);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.setUndecorated(true);
		frame.setVisible(true);
	}
}

先这么多，还有BUG，最小宽度和最小高度的处理还没弄，下班了，晚上回家再说。

[qysword]

学习一下，顶……

[yaochunpin]

真的实在感谢，像先生这么负责人的人真让人感动！

[yaochunpin]

谢谢了！

[Tassdars]

[code=Java]import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class ResizeFrame extends JFrame {
private boolean isTopLeft;// 是否处于左上角调整窗口状态
private boolean isTop;// 是否处于上边界调整窗口状态
private boolean isTopRight;// 是否处于右上角调整窗口状态
private boolean isRight;// 是否处于右边界调整窗口状态
private boolean isBottomRight;// 是否处于右下角调整窗口状态
private boolean isBottom;// 是否处于下边界调整窗口状态
private boolean isBottomLeft;// 是否处于左下角调整窗口状态
private boolean isLeft;// 是否处于左边界调整窗口状态
private final static int RESIZE_WIDTH = 5;// 判定是否为调整窗口状态的范围与边界距离
private final static int MIN_WIDTH = 20;// 窗口最小宽度
private final static int MIN_HEIGHT = 20;// 窗口最小高度

public ResizeFrame() {
addMouseMotionListener(new ResizeAdapter(this));
}

private class ResizeAdapter extends MouseAdapter {
private Component c;

public ResizeAdapter(Component c) {
this.c = c;
}

@Override
public void mouseMoved(MouseEvent event) {
int x = event.getX();
int y = event.getY();
int width = c.getWidth();
int height = c.getHeight();
int cursorType = Cursor.DEFAULT_CURSOR;// 鼠标光标初始为默认类型，若未进入调整窗口状态，保持默认类型
// 先将所有调整窗口状态重置
isTopLeft = isTop = isTopRight = isRight = isBottomRight = isBottom = isBottomLeft = isLeft = false;
if (y <= RESIZE_WIDTH) {
if (x <= RESIZE_WIDTH) {// 左上角调整窗口状态
isTopLeft = true;
cursorType = Cursor.NW_RESIZE_CURSOR;
} else if (x >= width - RESIZE_WIDTH) {// 右上角调整窗口状态
isTopRight = true;
cursorType = Cursor.NE_RESIZE_CURSOR;
} else {// 上边界调整窗口状态
isTop = true;
cursorType = Cursor.N_RESIZE_CURSOR;
}
} else if (y >= height - RESIZE_WIDTH) {
if (x <= RESIZE_WIDTH) {// 左下角调整窗口状态
isBottomLeft = true;
cursorType = Cursor.SW_RESIZE_CURSOR;
} else if (x >= width - RESIZE_WIDTH) {// 右下角调整窗口状态
isBottomRight = true;
cursorType = Cursor.SE_RESIZE_CURSOR;
} else {// 下边界调整窗口状态
isBottom = true;
cursorType = Cursor.S_RESIZE_CURSOR;
}
} else if (x <= RESIZE_WIDTH) {// 左边界调整窗口状态
isLeft = true;
cursorType = Cursor.W_RESIZE_CURSOR;
} else if (x >= width - RESIZE_WIDTH) {// 右边界调整窗口状态
isRight = true;
cursorType = Cursor.E_RESIZE_CURSOR;
}
// 最后改变鼠标光标
c.setCursor(new Cursor(cursorType));
}

@Override
public void mouseDragged(MouseEvent event) {
int x = event.getX();
int y = event.getY();
int width = c.getWidth();
int height = c.getHeight();
// 保存窗口改变后的x、y坐标和宽度、高度，用于预判是否会小于最小宽度、最小高度
int nextX = c.getX();
int nextY = c.getY();
int nextWidth = width;
int nextHeight = height;
if (isTopLeft || isLeft || isBottomLeft) {// 所有左边调整窗口状态
nextX += x;
nextWidth -= x;
}
if (isTopLeft || isTop || isTopRight) {// 所有上边调整窗口状态
nextY += y;
nextHeight -= y;
}
if (isTopRight || isRight || isBottomRight) {// 所有右边调整窗口状态
nextWidth = x;
}
if (isBottomLeft || isBottom || isBottomRight) {// 所有下边调整窗口状态
nextHeight = y;
}
if (nextWidth <= MIN_WIDTH) {// 如果窗口改变后的宽度小于最小宽度，则宽度调整到最小宽度
nextWidth = MIN_WIDTH;
if (isTopLeft || isLeft || isBottomLeft) {// 如果是从左边缩小的窗口，x坐标也要调整
nextX = c.getX() + width - nextWidth;
}
}
if (nextHeight <= MIN_HEIGHT) {// 如果窗口改变后的高度小于最小高度，则高度调整到最小高度
nextHeight = MIN_HEIGHT;
if (isTopLeft || isTop || isTopRight) {// 如果是从上边缩小的窗口，y坐标也要调整
nextY = c.getY() + height - nextHeight;
}
}
// 最后统一改变窗口的x、y坐标和宽度、高度，可以防止刷新频繁出现的屏闪情况
setBounds(nextX, nextY, nextWidth, nextHeight);
}
}

public static void main(String[] args) {
// 一个简单的演示小例子
JFrame frame = new ResizeFrame();
frame.setSize(400, 300);
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
frame.setLocation((screenSize.width - frame.getWidth()) / 2, (screenSize.height - frame.getHeight()) / 2);
frame.addMouseListener(new MouseAdapter() {
public void mouseClicked(MouseEvent event) {
if (event.getClickCount() > 1) {
System.exit(0);
}
}
});
frame.setUndecorated(true);
frame.setVisible(true);
}
}[code]

这个是完整版，更新如下：
1、优化了一下代码结构
2、解决了限制最小宽度和最小高度的问题
3、解决了左边和上边调整大小时的屏闪问题
4、加入了注释
5、解决了无法在窗体上直接结束程序的问题（双击窗体结束程序）

[Tassdars]

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class ResizeFrame extends JFrame {
	private boolean isTopLeft;// 是否处于左上角调整窗口状态
	private boolean isTop;// 是否处于上边界调整窗口状态
	private boolean isTopRight;// 是否处于右上角调整窗口状态
	private boolean isRight;// 是否处于右边界调整窗口状态
	private boolean isBottomRight;// 是否处于右下角调整窗口状态
	private boolean isBottom;// 是否处于下边界调整窗口状态
	private boolean isBottomLeft;// 是否处于左下角调整窗口状态
	private boolean isLeft;// 是否处于左边界调整窗口状态
	private final static int RESIZE_WIDTH = 5;// 判定是否为调整窗口状态的范围与边界距离
	private final static int MIN_WIDTH = 20;// 窗口最小宽度
	private final static int MIN_HEIGHT = 20;// 窗口最小高度
	
	public ResizeFrame() {
		addMouseMotionListener(new ResizeAdapter(this));
	}
	
	private class ResizeAdapter extends MouseAdapter {
		private Component c;
		
		public ResizeAdapter(Component c) {
			this.c = c;
		}
		
		@Override
		public void mouseMoved(MouseEvent event) {
			int x = event.getX();
			int y = event.getY();
			int width = c.getWidth();
			int height = c.getHeight();
			int cursorType = Cursor.DEFAULT_CURSOR;// 鼠标光标初始为默认类型，若未进入调整窗口状态，保持默认类型
			// 先将所有调整窗口状态重置
			isTopLeft = isTop = isTopRight = isRight = isBottomRight = isBottom = isBottomLeft = isLeft = false;
			if (y <= RESIZE_WIDTH) {
				if (x <= RESIZE_WIDTH) {// 左上角调整窗口状态
					isTopLeft = true;
					cursorType = Cursor.NW_RESIZE_CURSOR;
				} else if (x >= width - RESIZE_WIDTH) {// 右上角调整窗口状态
					isTopRight = true;
					cursorType = Cursor.NE_RESIZE_CURSOR;
				} else {// 上边界调整窗口状态
					isTop = true;
					cursorType = Cursor.N_RESIZE_CURSOR;
				}
			} else if (y >= height - RESIZE_WIDTH) {
				if (x <= RESIZE_WIDTH) {// 左下角调整窗口状态
					isBottomLeft = true;
					cursorType = Cursor.SW_RESIZE_CURSOR;
				} else if (x >= width - RESIZE_WIDTH) {// 右下角调整窗口状态
					isBottomRight = true;
					cursorType = Cursor.SE_RESIZE_CURSOR;
				} else {// 下边界调整窗口状态
					isBottom = true;
					cursorType = Cursor.S_RESIZE_CURSOR;
				}
			} else if (x <= RESIZE_WIDTH) {// 左边界调整窗口状态
				isLeft = true;
				cursorType = Cursor.W_RESIZE_CURSOR;
			} else if (x >= width - RESIZE_WIDTH) {// 右边界调整窗口状态
				isRight = true;
				cursorType = Cursor.E_RESIZE_CURSOR;
			}
			// 最后改变鼠标光标
			c.setCursor(new Cursor(cursorType));
		}
		
		@Override
		public void mouseDragged(MouseEvent event) {
			int x = event.getX();
			int y = event.getY();
			int width = c.getWidth();
			int height = c.getHeight();
			// 保存窗口改变后的x、y坐标和宽度、高度，用于预判是否会小于最小宽度、最小高度
			int nextX = c.getX();
			int nextY = c.getY();
			int nextWidth = width;
			int nextHeight = height;
			if (isTopLeft || isLeft || isBottomLeft) {// 所有左边调整窗口状态
				nextX += x;
				nextWidth -= x;
			}
			if (isTopLeft || isTop || isTopRight) {// 所有上边调整窗口状态
				nextY += y;
				nextHeight -= y;
			}
			if (isTopRight || isRight || isBottomRight) {// 所有右边调整窗口状态
				nextWidth = x;
			}
			if (isBottomLeft || isBottom || isBottomRight) {// 所有下边调整窗口状态
				nextHeight = y;
			}
			if (nextWidth <= MIN_WIDTH) {// 如果窗口改变后的宽度小于最小宽度，则宽度调整到最小宽度
				nextWidth = MIN_WIDTH;
				if (isTopLeft || isLeft || isBottomLeft) {// 如果是从左边缩小的窗口，x坐标也要调整
					nextX = c.getX() + width - nextWidth;
				}
			}
			if (nextHeight <= MIN_HEIGHT) {// 如果窗口改变后的高度小于最小高度，则高度调整到最小高度
				nextHeight = MIN_HEIGHT;
				if (isTopLeft || isTop || isTopRight) {// 如果是从上边缩小的窗口，y坐标也要调整
					nextY = c.getY() + height - nextHeight;
				}
			}
			// 最后统一改变窗口的x、y坐标和宽度、高度，可以防止刷新频繁出现的屏闪情况
			setBounds(nextX, nextY, nextWidth, nextHeight);
		}
	}
	
	public static void main(String[] args) {
		// 一个简单的演示小例子
		JFrame frame = new ResizeFrame();
		frame.setSize(400, 300);
		Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
		frame.setLocation((screenSize.width - frame.getWidth()) / 2, (screenSize.height - frame.getHeight()) / 2);
		frame.addMouseListener(new MouseAdapter() {
			public void mouseClicked(MouseEvent event) {
				if (event.getClickCount() > 1) {
					System.exit(0);
				}
			}
		});
		frame.setUndecorated(true);
		frame.setVisible(true);
	}
}

这个是完整版，更新如下：
1、优化了一下代码结构
2、解决了限制最小宽度和最小高度的问题
3、解决了左边和上边调整大小时的屏闪问题
4、加入了注释
5、解决了无法在窗体上直接结束程序的问题（双击窗体结束程序）

一个斜杠和CSDN帖子不能修改引发的杯具……

[mahaigss]

最近刚看这些 刚好用到证发愁呢哈哈 谢谢Tassdars 谢谢楼主
问题解决

[wen517913840]

我也遇到这个问题了 顶起 学习了