TextWatcher参数理解

class MyTextWatcher implements TextWatcher{  
  
        @Override  
        public void afterTextChanged(Editable s) {  
            // s是文本改变后的内容  
            Log.i("afterTextChanged", "afterTextChanged the text's length is "+etTest.length());  
            Log.i("afterTextChanged", "afterTextChanged the s is "+s.toString());  
            Log.i("afterTextChanged", "-------------------------------------");  
        }  
  
        @Override  
        public void beforeTextChanged(CharSequence s, int start, int count,  
                int after) {  
            // s是文本改变前的内容  
            // start是文本改变操作后输入光标所在位置  
            // count删除内容时是删除字符的个数，增加内容时为0  
            // after增加内容时是增加字符的个数，删除内容时为0 ，改变后新的内容的数量
            // 通过组件索引获得的text内容是改变前的  
            Log.i("beforeTextChanged", "beforeTextChanged the text's content is "+etTest.getText().toString());  
            Log.i("beforeTextChanged", "beforeTextChanged the text's length is "+etTest.length());  
            Log.i("beforeTextChanged", "beforeTextChanged the s is "+s);  
            Log.i("beforeTextChanged", "beforeTextChanged the start is "+start);  
            Log.i("beforeTextChanged", "beforeTextChanged the count is "+count);  
            Log.i("beforeTextChanged", "beforeTextChanged the after is "+after);  
            Log.i("beforeTextChanged", "-------------------------------------");  
        }  
  
        @Override  
        public void onTextChanged(CharSequence s, int start, int before,  
                int count) {  
            // s是文本改变后的内容  
            // start是文本改变操作后输入光标所在位置  
            // count增加内容时是增加字符的个数，删除内容时为0  
            // before删除内容时是删除字符的个数，增加内容时为0，被改变的内容的数量
            // 通过组件索引获得的text内容是改变后的  
            Log.i("onTextChanged", "onTextChanged the text's content is "+etTest.getText().toString());  
            Log.i("onTextChanged", "onTextChanged the text's length is "+etTest.length());  
            Log.i("onTextChanged", "onTextChanged the s is "+s);  
            Log.i("onTextChanged", "onTextChanged the start is "+start);  
            Log.i("onTextChanged", "onTextChanged the before is "+before);  
            Log.i("onTextChanged", "onTextChanged the count is "+count);  
            Log.i("onTextChanged", "-------------------------------------");  
        }  
          
    }