如何使用户可调整大小的JTextArea? [英] How to make user-resizable JTextArea?
本文介绍了如何使用户可调整大小的JTextArea?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
似乎唯一的选择是设置行数,但是我需要为用户调整文本区域的大小. JScrollPane有帮助,但是当文本很多时,我想让用户自己调整区域的大小.
Seems like the only option is to set number of rows, but I need my text area to be resizable for user. JScrollPane helps, but when there's a lot of text, I want to let user resize the area itself.
我该怎么做?如果我可以为此目的使用另一个类,那么我会完全同意的.
How do I do this? If I can use another class for this purpose, I'll be totally ok with it.
简化代码是
import javax.swing.*;
import java.awt.*;
public class Problematic {
public static void main(String[] args) {
JFrame f = new JFrame("frame");
f.setLayout(new BorderLayout());
JPanel p1 = new JPanel();
JPanel p = new JPanel();
JButton button = new JButton("Whatever here");
JTextArea t2 = new JTextArea(5, 30);
JScrollPane scrollPane = new JScrollPane(t2);
scrollPane.setSize(600, 400);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
t2.setText("this is some random text\nthat may go for many rows\nso it may look messy");
p1.add(button);
p.add(scrollPane);
f.add(p, BorderLayout.NORTH);
f.add(p1, BorderLayout.CENTER);
f.setSize(600, 500);
f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
f.setVisible(true);
}
}
推荐答案
作为第一个改进,您可以进行一些小的布局更改,以使JTextArea
占据整个空间并随着框架调整大小:
As first improvement you can make some small layout changes that will make the JTextArea
occupy the whole space and resize with the frame :
import java.awt.BorderLayout;
import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.WindowConstants;
public class Problematic {
public static void main(String[] args) {
JFrame f = new JFrame("frame");
f.setLayout(new BorderLayout());
JPanel p = new JPanel(new GridLayout(1, 1)); //assign gridlayout so text area fills panel
JTextArea t2 = new JTextArea(5, 30);
t2.setText("this is some random text\nthat may go for many rows\nso it may look messy");
JScrollPane scrollPane = new JScrollPane(t2);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
p.add(scrollPane);
f.add(p, BorderLayout.CENTER); //place text area panel in center position
JPanel p1 = new JPanel();
JButton button = new JButton("Whatever here");
p1.add(button);
f.add(p1, BorderLayout.PAGE_END);
f.setSize(600, 500);
f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
f.setVisible(true);
}
}
为获得更大的灵活性,您可以添加JSplitPane
:
for additional flexibility you can add a JSplitPane
:
public class Problematic {
public static void main(String[] args) {
JFrame f = new JFrame("frame");
f.getContentPane().setLayout(new BorderLayout());
JPanel p1 = new JPanel();
JButton button = new JButton("Whatever here");
p1.add(button);
JPanel p = new JPanel(new GridLayout(1, 1)); //assign gridlayout so text area fills panel
JTextArea t2 = new JTextArea(5, 30);
t2.setText("this is some random text\nthat may go for many rows\nso it may look messy");
JScrollPane scrollPane = new JScrollPane(t2); scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
p.add(scrollPane);
JSplitPane splitPane = new JSplitPane(JSplitPane.VERTICAL_SPLIT, p,p1);
f.getContentPane().add(splitPane, BorderLayout.CENTER);
f.setSize(600, 500);
f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
f.setVisible(true);
}
}
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