监听EditText输入事件

先定义如下EditText和TextWatcher :
    EditText editText;
    TextWatcher textWatcher;

(如下代码放在一个方法中)

editText.addTextChangedListener(textWatcher);
        textWatcher = new TextWatcher() {
            
            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                // TODO Auto-generated method stu
            }
            
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count,
                    int after) {
                // TODO Auto-generated method stub                 
            }
            
            @Override
            public void afterTextChanged(Editable s) {
                /**
                 * 在这个方法里面写EditText输入的监听事件
                 */
                
            }
        };