如何在按下第一个字符后显示 "Clear button" 并在文本为“”时隐藏它？

Question

我需要在编辑文本的右侧显示一个清除按钮，并在文本为“”时隐藏它。我该怎么做。

我只需要知道当文本长度>0或=0时如何显示和隐藏，仅此而已。

Answer 1

设置它的可见性从 xml。

If(editText1.getText.toString.length>0)
 {
  if(button1.getVisibility == View.GONE)
  {
  button1.setVisibility(View.VISIBLE)
   }
}
else
{
 if(button1.getVisibility == View.VISIBLE)
  {
  button1.setVisibility(View.GONE)
  }
}

Answer 2

试试这个代码

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)
        // set the visibility
    }
     });

Answer 3

您可以使用 TextWatcher，一种监听器类型：

yourEditText.addTextChangedListener(new TextWatcher() {

      public void afterTextChanged(Editable s) {

        //Here, you can check for text size...
        int length = editText.toString().length();
         [...]



      }

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

      public void onTextChanged(CharSequence s, int start, int before, int count) {}
   });
}

}

摘自 this question.

Answer 4

Here就是你的答案。

使用代码并通过检查字符长度在 textchange 上打开和关闭按钮可见性。

Answer 5

看看下面的代码，它可能对你有帮助:

EditText etSearch = (EditText) view.findViewById(R.id.etSearch);

etSearch.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                String str = etSearch.getText().toString();
                if (str.isEmpty()) {
                    btnClear.setVisibility(View.INVISIBLE);
                } else {
                    btnClear.setVisibility(View.VISIBLE);
                }
            }

            @Override
            public void afterTextChanged(Editable s) {

            }
        });

Answer 6

文本观察器可能适合您

If(editText1.getText.toString.length>0)
 {
  if(button1.getVisibility == View.GONE)
  {
  button1.setVisibility(View.VISIBLE)
  }
}
else
{
 if(button1.getVisibility == View.VISIBLE)
  {
  button1.setVisibility(View.GONE)
  }
}

如何在按下第一个字符后显示 "Clear button" 并在文本为“”时隐藏它？

How to show a "Clear button" after the first character pressed and hide it when the text is ""?

android

textwatcher

android-edittext