android的文本更改监听器

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

你用这个我已经提供了textchangelistner的最新方法

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

            @Override
            public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
                
                if (i2 == 0){
                    ////Edit text blanked
                } 
                
                String msg = charSequence.toString();/// your text on changed in edit text
                
            }

            @Override
            public void afterTextChanged(Editable editable) {

            }
        });

2022-12-14 11:48:54

其他回答

另一个可能会帮助别人的解决方案。有2个EditText，它们在编辑后相互改变。默认情况下，它导致了周期性。

使用变量:

Boolean uahEdited = false;
Boolean usdEdited = false;

添加TextWatcher

uahEdit = findViewById(R.id.uahEdit);
usdEdit = findViewById(R.id.usdEdit);

uahEdit.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
            if (!usdEdited) {
                uahEdited = true;
            }
        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            String tmp = uahEdit.getText().toString();

            if(!tmp.isEmpty() && uahEdited) {
                uah = Double.valueOf(tmp);
                usd = uah / 27;
                usdEdit.setText(String.valueOf(usd));
            } else if (tmp.isEmpty()) {
                usdEdit.getText().clear();
            }
        }

        @Override
        public void afterTextChanged(Editable s) {
            uahEdited = false;
        }
    });

usdEdit.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
            if (!uahEdited) {
                usdEdited = true;
            }
        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            String tmp = usdEdit.getText().toString();

            if (!tmp.isEmpty() && usdEdited) {
                usd = Double.valueOf(tmp);
                uah = usd * 27;
                uahEdit.setText(String.valueOf(uah));
            } else if (tmp.isEmpty()) {
                uahEdit.getText().clear();
            }
        }

        @Override
        public void afterTextChanged(Editable s) {
            usdEdited = false;
        }
    });

不要批评太多。我是一个开发新手

2020-06-26 19:00:45

在onCreate方法中动态添加背景:

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

也从XML中删除背景。

2019-12-16 10:00:44

你用这个我已经提供了textchangelistner的最新方法

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

            @Override
            public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
                
                if (i2 == 0){
                    ////Edit text blanked
                } 
                
                String msg = charSequence.toString();/// your text on changed in edit text
                
            }

            @Override
            public void afterTextChanged(Editable editable) {

            }
        });

2022-12-14 11:48:54

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) 
            {
            }
 });

2022-12-28 07:42:03

var filenameText = findViewById(R.id.filename) as EditText
filenameText.addTextChangedListener(object : TextWatcher {
    override fun afterTextChanged(s: Editable?) {
        filename = filenameText.text.toString()
        Log.i("FileName: ", filename)
    }
    
    override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {}
    override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {}
})

2020-08-03 08:21:07

android的文本更改监听器

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