当setText on editText texttwatcher.onTextChanged未被调用

Question

只要改变EditText字符串，就调用onTextChanged。

现在，当我启动一个新的Activity并通过Bundle发送数据时，onTextChanged没有被调用。

if( getIntent().getExtras() != null) {
    Bundle b = getIntent().getExtras();
    int value = -1;
    if(b != null)
        value = b.getInt("key");
    edit1.setText("Mywords:");
}

如何命名?

Answer 1

这是修改后的代码。这个想法是在添加TextWatcher之后在EditText中设置文本。

if( getIntent().getExtras() != null) {
    Bundle b = getIntent().getExtras();
    int value = -1;
    if(b != null)
        value = b.getInt("key");
    // Add  the TextWatcher here
    edit1.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
            // Toast.makeText(MainActivity.this, "before text changed", Toast.LENGTH_LONG).show();
        }
        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            // Toast.makeText(MainActivity.this, "on text changed", Toast.LENGTH_LONG).show();
        }
        @Override
        public void afterTextChanged(Editable s) {
            // Toast.makeText(MainActivity.this, "after text changed", Toast.LENGTH_LONG).show();
        }
    });
    // Now the set the value in your EditText
    edit1.setText("Mywords:");
}

Answer 2

确保在setText调用之前订阅TextWatcher

Answer 3

由于某种原因，方法addTextChangedListener没有为我调用。

然而doBeforeTextChanged, doOnTextChanged和doAfterTextChanged的方法效果很好:

amountTextField.doBeforeTextChanged { text, start, count, after ->
    Log.d(TAG, "beforeTextChange.") // OK, called
}
amountTextField.doOnTextChanged { text, start, before, count ->
    Log.d(TAG,  "onTextChanged.") // OK, called
}
amountTextField.doAfterTextChanged {
    Log.d(TAG, "afterTextChanged.") // OK, called
}
amountTextField.addTextChangedListener {
    object:  TextWatcher {
        override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
            Log.d(TAG, "beforeTextChange.") // NOK, not called
        }
        override fun onTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
            Log.d(TAG,  "onTextChanged.") // NOK, not called
        }
        override fun afterTextChanged(p0: Editable?) {
            Log.d(TAG,  "onTextChanged.") // NOK, not called
        }
    } }

顺便说一下，结果总是一样的:无论我是否将任何文本设置为我的EidtText，无论是在我设置任何文本之后还是之前。

Answer 4

尝试如下:

edit1.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) {
        }
    });

参考:android on Text Change Listener