Swingr的JTextField、JPasswordField设置圆角输入框

方法1：定义Border，然后给JTextField设置即可

摘自并整理：https://blog.csdn.net/u012093968/article/details/39316679

最好添加这句话g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON)告诉绘制API我们需要平滑一点，

否则绘制出来会有很多锯齿哟。

 package com.xxx.xxx.xxx;

 import java.awt.Color;
 import java.awt.Component;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
 import java.awt.Insets;
 import java.awt.RenderingHints;

 import javax.swing.border.Border;

 /**
  * Swing
  * 设置圆角边框（可以自定义边框的颜色）
  * 可以为button，文本框等人以组件添加边框
  * 使用方法：
  * JButton close = new JButton(" 关 闭 ");
  * close.setOpaque(false);// 设置原来按钮背景透明
  * close.setBorder(new RoundBorder());黑色的圆角边框
  * close.setBorder(new RoundBorder(Color.RED)); 红色的圆角边框
  * 
  * @author Monsoons
  */

 public class RoundBorder implements Border {
     private Color color;

     private int arcH = 15;
     private int arcW = 15;

     public RoundBorder() {
         this(Color.BLACK);
         // 如果实例化时，没有传值
         // 默认是黑色边框
     }

     public RoundBorder(Color color) {
         this.color = color;
     }

     public Insets getBorderInsets(Component c) {

         // top:可以调节光标与边枉的距离, 间接影响高度
         // left:可以调节光标与边枉的距离
         // bottom:可以调节光标与边枉的距离, 间接影响高度
         // right:可以调节光标与边枉的距离
         return new Insets(10, 15, 10, 15);
     }

     public boolean isBorderOpaque() {
         return false;
     }

     // 实现Border（父类）方法
     @Override
     public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) {
         //        g.setColor(color);
         //        g.drawRoundRect(0, 0, c.getWidth() - 1, c.getHeight() - 1, arcH, arcW);

         Graphics2D g2d = (Graphics2D) g.create();

         g2d.setColor(color);
         g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
         g2d.drawRoundRect(0, 0, c.getWidth() - 1, c.getHeight() - 1, arcH, arcW);

         g2d.dispose();
     }
 }

方法二： 重写JTextField，然后覆盖paintBorder方法

摘自：https://www.aliyun.com/jiaocheng/543166.html?spm=5176.100033.2.10.SPifa6

 /*Swing的圆角输入框
 发布时间：2018-03-01 来源：网络 上传者：用户
 关键字: 圆角 输入 Swing
 发表文章
 摘要：最近看了flyPig前辈的圆角高亮Buttonhttp://flypig.iteye.com/blog/389253,依葫芦画瓢,自己做了一个简单的圆角输入框。importjava.awt.Color;importjava.awt.FlowLayout;importjava.awt.Graphics;importjava.awt.Graphics2D;importjava.awt.Insets;importjava.awt.RenderingHints;importjava.

 最近看了flyPig前辈的圆角高亮Buttonhttp://flypig.iteye.com/blog/389253,依葫芦画瓢,自己做了一个简单的圆角输入框。*/

 import java.awt.Color;
 import java.awt.FlowLayout;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
 import java.awt.Insets;
 import java.awt.RenderingHints;
 import java.awt.Shape;
 import java.awt.event.MouseAdapter;
 import java.awt.event.MouseEvent;
 import java.awt.geom.RoundRectangle2D;
 import javax.swing.JFrame;
 import javax.swing.JTextField;

 public class MyTextField extends JTextField {
     private static final long serialVersionUID = -1946802815417758252L;

     public MyTextField(int columns) {
         super(columns);
         //
         setMargin(new Insets(0, 5, 0, 5));
     }

     @Override
     protected void paintBorder(Graphics g) {
         int h = getHeight();// 从JComponent类获取高宽
         int w = getWidth();
         Graphics2D g2d = (Graphics2D) g.create();
         Shape shape = g2d.getClip();
         g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
         g2d.setClip(shape);
         g2d.drawRoundRect(0, 0, w - 2, h - 2, h, h);
         g2d.dispose();
         super.paintBorder(g2d);
     }

     public static void main(String[] args) {
         JFrame jf = new JFrame();
         jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         jf.setSize(300, 200);
         jf.setLayout(new FlowLayout());
         MyTextField text = new MyTextField(20);
         jf.add(text);
         jf.setVisible(true);
     }
 }