android :KeyListener这个接口在android.text.method中

它有如下子类:

BaseKeyListener,DateKeyListener,DateTimeKeyListener,

DialerKeyListener,DigitsKeyListener,MultiTapKeyListener,

NumberKeyListener,QwertyKeyListener,TextKeyListener,

TimeKeyListener

今天要使用KeyListener来让EditText只能输入某些字符，如数字，大小写a~z等等

keylistener有如下函数：

public int getInputType();

public boolean onKeyDown(View view, Editable text,

int keyCode, KeyEvent event);

public boolean onKeyUp(View view, Editable text,

int keyCode, KeyEvent event);

public boolean onKeyOther(View view, Editable text, KeyEvent event);

public void clearMetaKeyState(View view, Editable content, int states);

NumberKeyListener定义

public abstract class NumberKeyListener extends BaseKeyListener implements InputFilter

里面有一个抽象函数：protected abstract char[] getAcceptedChars();

这个函数就是用来编写自己想要输入的字符数据：

比如：

public char [] getAcceptedChars(){

char numberChars[] ={'0'  , '1' ,'2' ,' 3' , ' 4' , '5'  ,'6'  ,' 7 ' ,  '8'  , '9'};

return numberChars;

}

public char [] getAcceptedChars(){

char [] myChar ={'a','b','c','d','e','f','g','h','i'.......};

return myChar;

}

editText.setKeyListener(new numberKeyListener(){

..........

把抽象函数实现

});