谁能告诉我如何控制textarea的输入长度啊？我输入不了多少文字就不能加了。。

[akingzhen]

RT，谢谢大家啊~~~帮帮我哈`~~

[gdsean]

one way u can do like this,

The following two classes are to create a textfield with
restricting the number of characters to be entered into it.
=============================================================
public class FixedLengthPlainDocument extends PlainDocument {

private int maxLength;

public FixedLengthPlainDocument(int maxLength) {
this.maxLength = maxLength;
}
public void insertString(int offset, String str,
AttributeSet a)
throws BadLocationException {
if(getLength() + str.length() > maxLength) {
Toolkit.getDefaultToolkit().beep();
}
else {
super.insertString(offset, str, a);
}
}

}

public class FixedLengthTextArea extends JTextArea{

public FixedLengthTextArea (int length)
{
this(null, length);
}

public FixedLengthTextArea (String text, int length) {
super(new FixedLengthPlainDocument(length), text,
length);
}
}
=========================================================

so now u can create ur text field as
JTextArea tf = new FixedLengthTextArea (10);

[Sundery]

简单的话，我觉得用.size()或者.length()来控制也蛮好：）

[bonnyone]

我决的给这个textarea加个KeyTyped接口，在接口函数中控制长度!

[whyxx]

flybird0923(追梦人) ( ) 的方法比较简单,效果也不错

[oopliu]

study!