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);
    }
}