在Kotlin中简单使用KTX扩展函数: (它使用TextWatcher)

yourEditText.doOnTextChanged { text, start, count, after -> 
        // action which will be invoked when the text is changing
    }

进口core-KTX:

implementation "androidx.core:core-ktx:1.2.0"

在onCreate方法中动态添加背景:

getWindow().setBackgroundDrawableResource(R.drawable.background);

也从XML中删除背景。

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。

您可以添加一个检查，只在字段中的文本不为空时清除(即当长度不等于0时)。

field1.addTextChangedListener(new TextWatcher() {

   @Override
   public void afterTextChanged(Editable s) {}

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

   @Override    
   public void onTextChanged(CharSequence s, int start,
     int before, int count) {
      if(s.length() != 0)
        field2.setText("");
   }
  });

field2.addTextChangedListener(new TextWatcher() {

   @Override
   public void afterTextChanged(Editable s) {}

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

   @Override
   public void onTextChanged(CharSequence s, int start,
     int before, int count) {
      if(s.length() != 0)
         field1.setText("");
   }
  });

这里是TextWatcher的文档。

另外，请尊重命名约定。

这个回答有点晚了，但这里有一个可重复使用的解决方案:

/**
 * An extension of TextWatcher which stops further callbacks being called as 
 * a result of a change happening within the callbacks themselves.
 */
public abstract class EditableTextWatcher implements TextWatcher {

    private boolean editing;

    @Override
    public final void beforeTextChanged(CharSequence s, int start, 
                                                    int count, int after) {
        if (editing)
            return;

        editing = true;
        try {
            beforeTextChange(s, start, count, after);
        } finally {
            editing = false;
        }
    }

    protected abstract void beforeTextChange(CharSequence s, int start, 
                                                     int count, int after);

    @Override
    public final void onTextChanged(CharSequence s, int start, 
                                                int before, int count) {
        if (editing)
            return;

        editing = true;
        try {
            onTextChange(s, start, before, count);
        } finally {
            editing = false;
        }
    }

    protected abstract void onTextChange(CharSequence s, int start, 
                                            int before, int count);

    @Override
    public final void afterTextChanged(Editable s) {
        if (editing)
            return;

        editing = true;
        try {
            afterTextChange(s);
        } finally {
            editing = false;
        }
    }

    public boolean isEditing() {
        return editing;
    }

    protected abstract void afterTextChange(Editable s);
}

因此，当使用上述方法时，在TextWatcher中发生的任何setText()调用都不会导致TextWatcher再次被调用:

/**
 * A setText() call in any of the callbacks below will not result in TextWatcher being 
 * called again.
 */
public class MyTextWatcher extends EditableTextWatcher {

    @Override
    protected void beforeTextChange(CharSequence s, int start, int count, int after) {
    }

    @Override
    protected void onTextChange(CharSequence s, int start, int before, int count) {
    }

    @Override
    protected void afterTextChange(Editable s) {
    }
}

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) 
            {
            }
 });