Question

键盘监听，文本框之内 只允许输入1-99之间数字，怎么写呀

Answer 1

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

class CustomedDocument extends PlainDocument {
private int limit;

public CustomedDocument (int limit) {
super();
this.limit = limit;
}

public void insertString (int offset, String str, AttributeSet attr) throws BadLocationException {
if (this.getLength() + str.length() > limit)
return;

char charArray[] = str.toCharArray();
for (char c : charArray)
if ((this.getLength() == 0 && c < '1') || (this.getLength() != 0 && c < '0') || c > '9')
return;
super.insertString(offset, str, attr);
}
}

public class Demo {
private JFrame mainFrame;
private JTextField txtInput;

public Demo () {
Toolkit tk = Toolkit.getDefaultToolkit();
Dimension dms = tk.getScreenSize();
Font f = new Font("Arial", Font.PLAIN, 13);

mainFrame = new JFrame("Demo");
mainFrame.setLayout(null);
mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainFrame.setBounds((int)dms.getWidth()/2-95, (int)dms.getHeight()/2-50, 190, 73);

txtInput = new JTextField();
txtInput.setBounds(5, 5, 165, 25);
txtInput.setFont(f);
txtInput.setDocument(new CustomedDocument(2));

mainFrame.add(txtInput);
mainFrame.setVisible(true);
}

public static void main (String args[]) throws InstantiationException, ClassNotFoundException, IllegalAccessException, UnsupportedLookAndFeelException {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
new Demo();
}
}

Answer 2

为了这个简单的功能，去学功能庞大的正则表达式，恐怕有点小题大作，不妨对文本框加一个事件mouseOut

如果焦点离开了该文本框，则检查文本框内的值，如果满足条件>1&&<99则继续，否则焦点回来文本框，并提示“1<输入的数<99”，确认后清空文本框的内容

祝你成功！

Answer 3

<input maxlength=2
onkeypress="var k=event.keyCode; return k>=48&&k<=57"
onpaste="return !clipboardData.getData('text').match(/\D/)"
ondragenter="return false"
style="ime-mode:Disabled"
>

Answer 4

</script>
<input type="text" onkeypress="return blo(this,event)" id="t1">
<script type="text/javascript">
function blo(text1,oevent){
//var str = "0123456789";
//var str = /^[1-9]\d*|0$/; //匹配数字，就是符合这个就只能输入数字
var str = /^[a-zA-Z]+$/; //匹配字母
var key;
if(window.event){//key为该字符的按键代码
key = window.event.keyCode; //IE浏览器
}else if(oevent){
key = oevent.charCode; //Firefox浏览器
}
var schar = String.fromCharCode(key);//得到字符代码
if(str.test(schar)){
return s;
} else{
return false;
}
}

</script>

Answer 5

<input
maxlength=2
onkeypress="var
k=event.keyCode;
return
k>=48&&k<=57"
onpaste="return
!clipboardData.getData('text').match(/\D/)"
ondragenter="return
false"
style="ime-mode:Disabled"
>

Answer 6

为了这个简单的功能，去学功能庞大的正则表达式，恐怕有点小题大作，不妨对文本框加一个事件mouseOut
如果焦点离开了该文本框，则检查文本框内的值，如果满足条件>1&&<99则继续，否则焦点回来文本框，并提示“1<输入的数<99”，确认后清空文本框的内容
祝你成功！