EditText和获取字符

Question

我如何可以获得我编辑视图中写入的charakters数量？我想检查这个数字，因为当我写更多然后3我想要使用alertdialog。我如何以简单的方式做到这一点？

Answer 1

使用TextWatcher用于在计数的EditText焦炭：

private CharSequence temp; 
    mEditText = (EditText)findViewById(R.id.ET); 
     mEditText.addTextChangedListener(mTextWatcher); 

     TextWatcher mTextWatcher = new TextWatcher() { 
       @Override 
       public void beforeTextChanged(CharSequence s, int arg1, int arg2, 
         int arg3) { 
        temp = s; 
       } 

       @Override 
       public void onTextChanged(CharSequence s, int arg1, int arg2, 
         int arg3) { 

       } 

       @Override 
       public void afterTextChanged(Editable s) { 
        // check here length of text in EditText after change 
      if (temp.length() > 3) { 
       // your alertdialog 
     } 
       } 
      }; 

Answer 2

你需要使用TextWatcher来做到这一点。

yourEditText.addTextChangedListener(new TextWatcher() { 

     @Override 
     public void onTextChanged(CharSequence s, int start, int before, 
     int count) { 
      // TODO Auto-generated method stub 

     } 

     @Override 
     public void beforeTextChanged(CharSequence s, int start, int count, 
       int after) { 
      // TODO Auto-generated method stub 

     } 

     @Override 
     public void afterTextChanged(Editable s) { 
      // TODO Auto-generated method stub 

     } 
    }); 

使用任何方法来保持量的跟踪和显示警告如果适用