我正在尝试制作一个按钮来计算文本字段中的字符 [英] I'm trying to make a button to count characters in a text field

问题描述

我正在尝试使用 JButton count 来计算输入到 JTextField t 中的字符数.我是 Java 和 GUI 的新手，但这是我的代码:

I'm trying to use the JButton count to count the number of characters entered into the JTextField t. I'm new to Java and GUIs but here's my code:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class GUI1 extends Frame implements ActionListener{

    TextField t; 
    Button count;
    int a;
    Choice choice;

    public GUI1(){

        this.t = new TextField("", 30);

        this.count = new Button("count");
        this.count.addActionListener(this);

        JTextField x = new JTextField();
        x.setEditable(false);

        this.setTitle("Character count");
        this.setLayout(new FlowLayout());

        this.add(x);
        this.add(t);
        this.add(count);

        this.pack();
        this.setVisible(true);

    }

    public void actionPerformed(ActionEvent e) {
        if(e.getSource()== this.count) 


       t.setText(choice.getSelectedItem()+ " " +a);
    }

我还试图在另一个不可编辑的 JTextField x 中输入值.任何帮助表示赞赏.

I'm also trying to enter the value in another uneditable JTextField x. Any help is appreciated.

推荐答案

首先，我建议你不要使用 AWT 元素，因为它带来了很多问题，而且几乎没有支持，相反，您可以尝试使用 Swing 组件，它们是 AWT 的替代/修复.您可以在此处阅读更多信息.您可能还想阅读AWT vs Swing(优点和缺点).

First of all, I recommend you not to use AWT elements, since it brings tons of problems and it has little to no support, instead you can try using Swing components which are a replacement/fix for AWT. You can read more about here. You might also want to read AWT vs Swing (Pros and Cons).

现在进入你的问题:

您应该避免从 JFrame 扩展，我建议您改为创建一个新的 JFrame 对象.原因如下.话虽如此，您还可以使用 this 删除所有 this.t 和其他调用.

You should avoid extending from JFrame, I might recommend you to create a new JFrame object instead. Here's the reason to why. That being said, you can also remove all your this.t and other calls with this.

很高兴您使用了布局管理器！

I'm glad you're using a Layout Manager!

现在要计算 JTextField 上的字符数并将文本设置为其他 JTextField，您应该使用以下代码:

And now to count the number of characters on your JTextField and set text to your other JTextField you should use this code:

count.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
        int count = t.getText().length();
        System.out.println(count);
        x.setText(t.getText());
    }
});

我还修复了您的代码，我将 AWT 元素更改为 Swing 元素，并将列数添加到您的第二个 JTextField 以便它出现.

Also I fixed your code, I changed AWT elements to Swing ones and added number of cols to your second JTextField so it would appear.

所以，这是我根据您的代码制作的运行示例(并删除了 Choice choice 行，因为您没有发布该代码):

So, here's a running example that I made from your code (And removed Choice choice line since you didn't posted that code):

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class GUI1 {

    JTextField t; 
    JButton count;
    int a;
    JFrame frame;

    public GUI1(){
        frame = new JFrame();
        t = new JTextField("", 15);
        count = new JButton("count");
        JTextField x = new JTextField("", 15);
        x.setEditable(false);

        count.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                int count = t.getText().length();
                System.out.println(count);
                x.setText(t.getText());
            }
        });

        frame.setTitle("Character count");
        frame.setLayout(new FlowLayout());

        frame.add(x);
        frame.add(t);
        frame.add(count);

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);

    }

    public static void main (String args[]) {
        new GUI1();
    }
}

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