基于swing实现窗体拖拽和拉伸

本文为大家分享了swing实现窗体拖拽和拉伸的具体代码，供大家参考，具体内容如下

当用setundecorated(true) 后 jframe去掉标题栏后就得自己写拖拽和拉伸功能了。

下面是效果图，我的截图软件不能够截取除系统默认光标外的光标，所以各个方向光标变化在图中没有体现

代码如下：

import javax.swing.*; 
import java.awt.*; 
 
/** 
 * 窗体拖拽和拉伸 
 */ 
public class winresizedemo { 
 private jframe jf; 
 public winresizedemo(){ 
  jf=new jframe(); 
  jf.setundecorated(true);//去标边界和标题栏 
  jf.setlocationrelativeto(null);//窗口置中 
  jf.setsize(400,400); 
  jf.setdefaultcloseoperation(jframe.exit_on_close); 
  resizeevent dg = new resizeevent(jf); 
  /**添加两个监听器**/ 
  jf.addmouselistener(dg); 
  jf.addmousemotionlistener(dg); 
  jf.setvisible(true); 
 } 
 public static void main(string [] args){ 
  new winresizedemo(); 
 } 
} 

import javax.swing.*; 
import java.awt.*; 
import java.awt.event.mouseadapter; 
import java.awt.event.mouseevent; 
/** 
 * 实现窗口各个方向拉伸以及拖动。 
 */ 
public class resizeevent extends mouseadapter{ 
 public jframe jf; 
 private point prepos,curpos,jfpos; 
 private static final double breadth = 15.0;//边界拉伸范围 
 private int dragtype; 
 private static final int drag_move = 1; 
 private static final int drag_up = 2; 
 private static final int drag_upleft = 3; 
 private static final int drag_upright = 4; 
 private static final int drag_left = 5; 
 private static final int drag_right = 6; 
 private static final int drag_bottom = 7; 
 private static final int drag_bottomleft = 8; 
 private static final int drag_bottomright = 9; 
 public resizeevent(jframe jf){ 
  this.jf = jf; 
 } 
 @override 
 public void mousepressed(mouseevent e){ 
  prepos = e.getlocationonscreen(); 
 } 
 @override 
 public void mousemoved(mouseevent e){ 
  areacheck(e.getpoint()); 
 } 
 @override 
 public void mousedragged(mouseevent e){ 
  curpos = e.getlocationonscreen(); 
  jfpos = jf.getlocation(); 
  dragaction(); 
  prepos = curpos; 
 } 
 private void dragaction(){ 
  switch(dragtype){ 
   case drag_move: 
    jf.setlocation(jfpos.x+curpos.x-prepos.x, 
      jfpos.y+curpos.y-prepos.y); 
    break; 
   case drag_up://x位置不变，y位置变化，并且height变化 
    jf.setlocation(jfpos.x, 
      jfpos.y+curpos.y-prepos.y); 
    jf.setsize(jf.getwidth(), jf.getheight()-(curpos.y-prepos.y)); 
    break; 
   case drag_left://y位置不变，x位置变化，width变化 
    jf.setlocation(jfpos.x+curpos.x-prepos.x, 
      jfpos.y); 
    jf.setsize(jf.getwidth()-(curpos.x-prepos.x), jf.getheight()); 
    break; 
   case drag_right://x,y位置不变，width变化 
    jf.setlocation(jfpos.x, 
      jfpos.y); 
    jf.setsize(jf.getwidth()+(curpos.x-prepos.x), jf.getheight()); 
    break; 
   case drag_bottom://x,y位置不变，height变化 
    jf.setlocation(jfpos.x, 
      jfpos.y); 
    jf.setsize(jf.getwidth(), jf.getheight()+(curpos.y-prepos.y)); 
    break; 
   case drag_upleft://x,y位置均变化，h,w均变化 
    jf.setlocation(jfpos.x+curpos.x-prepos.x, 
      jfpos.y+curpos.y-prepos.y); 
    jf.setsize(jf.getwidth()-(curpos.x-prepos.x), jf.getheight()-(curpos.y-prepos.y)); 
    break; 
   case drag_bottomright://x,y位置均不变，h,w变化 
    jf.setlocation(jfpos.x, 
      jfpos.y); 
    jf.setsize(jf.getwidth()+(curpos.x-prepos.x), jf.getheight()+(curpos.y-prepos.y)); 
    break; 
   case drag_upright://x位置不变，y,w,h变化 
    jf.setlocation(jfpos.x, 
      jfpos.y+curpos.y-prepos.y); 
    jf.setsize(jf.getwidth()+(curpos.x-prepos.x), jf.getheight()-(curpos.y-prepos.y)); 
    break; 
   case drag_bottomleft://y不变，xwh变化 
    jf.setlocation(jfpos.x+curpos.x-prepos.x, 
      jfpos.y); 
    jf.setsize(jf.getwidth()-(curpos.x-prepos.x), jf.getheight()+(curpos.y-prepos.y)); 
    break; 
   default: 
    break; 
  } 
 } 
 private boolean areacheck(point p){ 
  if(p.getx()<=breadth && p.gety()<=breadth){ 
   dragtype = drag_upleft; 
   jf.setcursor(new cursor(cursor.nw_resize_cursor)); 
  }else if(p.getx()>breadth 
    && p.getx()<(jf.getwidth()-breadth) 
    && p.gety()<=breadth){ 
   dragtype = drag_up; 
   jf.setcursor(new cursor(cursor.n_resize_cursor)); 
  }else if(p.getx()>=(jf.getwidth()-breadth) && p.gety()<=breadth){ 
   dragtype = drag_upright; 
   jf.setcursor(new cursor(cursor.ne_resize_cursor)); 
  }else if(p.getx()<=breadth 
    && p.gety()<(jf.getheight()-breadth) 
    && p.gety()>breadth){ 
   dragtype = drag_left; 
   jf.setcursor(new cursor(cursor.w_resize_cursor)); 
  }else if(p.getx()>=(jf.getwidth()-breadth) 
    && p.gety()<(jf.getheight()-breadth) 
    && p.gety()>breadth){ 
   dragtype = drag_right; 
   jf.setcursor(new cursor(cursor.e_resize_cursor)); 
  }else if(p.getx()<=breadth 
    && p.gety()>=(jf.getheight()-breadth)){ 
   dragtype = drag_bottomleft; 
   jf.setcursor(new cursor(cursor.sw_resize_cursor)); 
  }else if(p.getx()>breadth 
    && p.getx()<(jf.getwidth()-breadth) 
    && p.gety()>=(jf.getheight()-breadth)){ 
   dragtype = drag_bottom; 
   jf.setcursor(new cursor(cursor.s_resize_cursor)); 
  }else if(p.getx()>=(jf.getwidth()-breadth) 
    && p.gety()>=(jf.getheight()-breadth)){ 
   dragtype = drag_bottomright; 
   jf.setcursor(new cursor(cursor.se_resize_cursor)); 
  }else{ 
   dragtype = drag_move; 
   jf.setcursor(new cursor(cursor.move_cursor)); 
   return false; 
  } 
  return true; 
 } 
} 

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。