JTextArea圆角 [英] JTextArea Rounded Corners
本文介绍了JTextArea圆角的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我想使JTextArea具有圆角，并且我执行了以下代码:
public BPosTxtArea() {
super();
setOpaque(false);
}
@Override
protected void paintComponent(Graphics g) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(getBackground());
g2.fillRoundRect(0, 0, getWidth() - 1, getHeight() - 1, 15, 15);
super.paintComponent(g);
}
@Override
protected void paintBorder(Graphics g) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(new Color(102, 102, 102));
g2.drawRoundRect(0, 0, getWidth() - 1, getHeight() - 1, 15, 15);
}
但是它的外部仍然有一个方形的边框，如下面的波纹图所示:
有人可以帮助我吗?
解决方案
首先查看如何使用边框
这是一个非常简单的示例:
public class RoundBorder implements Border {
private int radius;
public RoundBorder(int radius) {
this.radius = radius;
}
public int getRadius() {
return radius;
}
@Override
public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.draw(new RoundRectangle2D.Double(x, y, width - 1, height - 1, getRadius(), getRadius()));
g2d.dispose();
}
@Override
public Insets getBorderInsets(Component c) {
int value = getRadius() / 2;
return new Insets(value, value, value, value);
}
@Override
public boolean isBorderOpaque() {
return false;
}
}
import java.awt.Component;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.geom.RoundRectangle2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.Border;
public class Example {
public static void main(String[] args) {
new Example();
}
public Example() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
JTextArea ta = new JTextArea(10, 20);
ta.setBorder(new RoundBorder(20));
JScrollPane sp = new JScrollPane(new JTextArea(10, 20));
sp.setBorder(new RoundBorder(20));
add(ta, gbc);
add(sp, gbc);
}
}
public class RoundBorder implements Border {
private int radius;
public RoundBorder(int radius) {
this.radius = radius;
}
public int getRadius() {
return radius;
}
@Override
public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.draw(new RoundRectangle2D.Double(x, y, width - 1, height - 1, getRadius(), getRadius()));
g2d.dispose();
}
@Override
public Insets getBorderInsets(Component c) {
int value = getRadius() / 2;
return new Insets(value, value, value, value);
}
@Override
public boolean isBorderOpaque() {
return false;
}
}
}
问题是，边框在组件填充区域内"被绘制，这意味着角将与填充区域具有相同的颜色.使用Border无法解决它.
诀窍是创建第二个组件，您可以在其上绘制边框(通过paintComponent，用与文本区域相同的颜色填充边框内的区域)，然后将该组件添加到其中. /p>
已更新
根据您的代码示例，您不会覆盖getInsets，这将是非常重要的，另一件事是，您的JTextArea似乎在JScrollPane内...
public class BPosTextArea extends JTextArea {
private int radius;
public BPosTextArea() {
super(10, 20);
setOpaque(false);
setBorder(null);
setRadius(20);
}
@Override
protected void paintComponent(Graphics g) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(getBackground());
g2.fillRoundRect(0, 0, getWidth() - 1, getHeight() - 1, getRadius(), getRadius());
super.paintComponent(g);
}
@Override
protected void paintBorder(Graphics g) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(new Color(102, 102, 102));
g2.drawRoundRect(0, 0, getWidth() - 1, getHeight() - 1, getRadius(), getRadius());
}
public void setRadius(int radius) {
this.radius = radius;
repaint();
}
public int getRadius() {
return radius;
}
@Override
public Insets getInsets() {
int value = getRadius() / 2;
return new Insets(value, value, value, value);
}
}
一种解决方案是将JScrollPane
border设置为nullI want to make JTextArea has a rounded corners, and i did this code :
public BPosTxtArea() {
super();
setOpaque(false);
}
@Override
protected void paintComponent(Graphics g) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(getBackground());
g2.fillRoundRect(0, 0, getWidth() - 1, getHeight() - 1, 15, 15);
super.paintComponent(g);
}
@Override
protected void paintBorder(Graphics g) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(new Color(102, 102, 102));
g2.drawRoundRect(0, 0, getWidth() - 1, getHeight() - 1, 15, 15);
}
but it still has a square border outside like picture bellow :
Can anyone help me?
解决方案
Start by having a look at How to Use Borders
This is a very simple example:
public class RoundBorder implements Border {
private int radius;
public RoundBorder(int radius) {
this.radius = radius;
}
public int getRadius() {
return radius;
}
@Override
public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.draw(new RoundRectangle2D.Double(x, y, width - 1, height - 1, getRadius(), getRadius()));
g2d.dispose();
}
@Override
public Insets getBorderInsets(Component c) {
int value = getRadius() / 2;
return new Insets(value, value, value, value);
}
@Override
public boolean isBorderOpaque() {
return false;
}
}
import java.awt.Component;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.geom.RoundRectangle2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.Border;
public class Example {
public static void main(String[] args) {
new Example();
}
public Example() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
JTextArea ta = new JTextArea(10, 20);
ta.setBorder(new RoundBorder(20));
JScrollPane sp = new JScrollPane(new JTextArea(10, 20));
sp.setBorder(new RoundBorder(20));
add(ta, gbc);
add(sp, gbc);
}
}
public class RoundBorder implements Border {
private int radius;
public RoundBorder(int radius) {
this.radius = radius;
}
public int getRadius() {
return radius;
}
@Override
public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.draw(new RoundRectangle2D.Double(x, y, width - 1, height - 1, getRadius(), getRadius()));
g2d.dispose();
}
@Override
public Insets getBorderInsets(Component c) {
int value = getRadius() / 2;
return new Insets(value, value, value, value);
}
@Override
public boolean isBorderOpaque() {
return false;
}
}
}
Problems, the border is painted "within" the component fill area, meaning that the corners will be the same color as the fill area. There's no way around it using Border.
The trick would be to create a second component, onto which you could paint the border (via the paintComponent, filling the area within the border the same color as the text area) and then add the component into that.
Updated
Based on you code example, you're not overriding getInsets, which is going to be very important, the other thing is, it appears that your JTextArea is within a JScrollPane...
public class BPosTextArea extends JTextArea {
private int radius;
public BPosTextArea() {
super(10, 20);
setOpaque(false);
setBorder(null);
setRadius(20);
}
@Override
protected void paintComponent(Graphics g) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(getBackground());
g2.fillRoundRect(0, 0, getWidth() - 1, getHeight() - 1, getRadius(), getRadius());
super.paintComponent(g);
}
@Override
protected void paintBorder(Graphics g) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(new Color(102, 102, 102));
g2.drawRoundRect(0, 0, getWidth() - 1, getHeight() - 1, getRadius(), getRadius());
}
public void setRadius(int radius) {
this.radius = radius;
repaint();
}
public int getRadius() {
return radius;
}
@Override
public Insets getInsets() {
int value = getRadius() / 2;
return new Insets(value, value, value, value);
}
}
A solution is to set the border to null for the JScrollPane
这篇关于JTextArea圆角的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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