我有一个情况,有两个领域。Field1和field2。我想要的 当field1被改变时,要做的是空field2,反之亦然。所以只有在最后 一个字段上有内容。

field1 = (EditText)findViewById(R.id.field1);
field2 = (EditText)findViewById(R.id.field2);

field1.addTextChangedListener(new TextWatcher() {

   public void afterTextChanged(Editable s) {}

   public void beforeTextChanged(CharSequence s, int start,
     int count, int after) {
   }

   public void onTextChanged(CharSequence s, int start,
     int before, int count) {
      field2.setText("");
   }
  });

field2.addTextChangedListener(new TextWatcher() {

   public void afterTextChanged(Editable s) {}

   public void beforeTextChanged(CharSequence s, int start,
     int count, int after) {
   }

   public void onTextChanged(CharSequence s, int start,
     int before, int count) {
     field1.setText("");
   }
  });

它工作得很好,如果我附加addTextChangedListener到field1,但当 我对两个字段都这么做,应用程序崩溃了。显然是因为他们想要改变 无限地相互联系。一旦field1改变,此时它就会清除field2 Field2被更改,因此它将清除field1,以此类推……

谁能给点建议吗?


当前回答

editText.addTextChangedListener(new TextWatcher() 
{
            @Override
            public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) 
            {
            }

            @Override
            public void onTextChanged(CharSequence chr, int i, int i1, int i2) 
            {
                //Check char sequence is empty or not
                if (chr.length() > 0)
                {
                    //Your Code Here
                }
            }

            @Override
            public void afterTextChanged(Editable editable) 
            {
            }
 });

其他回答

我写了自己的扩展,对我很有帮助。(芬兰湾的科特林)

你可以这样写:

editText.customAfterTextChanged { editable -> 
    //You have accessed the editable object. 
}

我的分机号:

fun EditText.customAfterTextChanged(action: (Editable?)-> Unit){
    this.addTextChangedListener(object : TextWatcher {
       override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {}
       override fun onTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {}
       override fun afterTextChanged(editable: Editable?) {
        action(editable)
    }
})}

你也可以使用hasFocus()方法:

public void onTextChanged(CharSequence s, int start,
     int before, int count) {
     if (Field2.hasfocus()){
         Field1.setText("");
     }
   }

我在大学作业中测试了这个方法,在用户输入温标时转换温标。效果很好,而且简单多了。

editText.addTextChangedListener(new TextWatcher() 
{
            @Override
            public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) 
            {
            }

            @Override
            public void onTextChanged(CharSequence chr, int i, int i1, int i2) 
            {
                //Check char sequence is empty or not
                if (chr.length() > 0)
                {
                    //Your Code Here
                }
            }

            @Override
            public void afterTextChanged(Editable editable) 
            {
            }
 });

我也遇到过同样的问题,并不断得到stackOverflow异常,我提出了以下解决方案。

edt_amnt_sent.addTextChangedListener(new TextWatcher() {    
    @Override
    public void afterTextChanged(Editable s) {
        if (skipOnChange)
            return;

        skipOnChange = true;
        try {
            //method
        } catch (NumberFormatException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            skipOnChange = false;
        }
    }
});

edt_amnt_receive.addTextChangedListener(new TextWatcher() {

    @Override
    public void afterTextChanged(Editable s) {

        if (skipOnChange)
            return;

        skipOnChange = true;
        try {
            //method
        } catch (NumberFormatException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            skipOnChange = false;
        }
    }
});

skipOnChange = false;

etSearch.addTextChangedListener(object : TextWatcher {
     override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
          TODO("Not yet implemented")
     }

     override fun onTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
          TODO("Not yet implemented")
     }

     override fun afterTextChanged(p0: Editable?) {
          TODO("Not yet implemented")
     }
})