Android UI update notification

Question

我的视图中有 3 个 Edittexts 和 3 个微调器，每当任何 edittext 文本值发生变化或任何微调器选择发生变化时，我都必须进行 service cal ，我如何获得通知，例如 edittext 或微调器选择发生变化？

Answer 1

You need to add listeners to the EditTexts and Spinners.

For the EditTexts try this:

editText1.addTextChangedListener(new TextWatcher() {
    @Override
    public void afterTextChanged(Editable s) {
        // your code here
    }

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

    @Override    
    public void onTextChanged(CharSequence s, int start, int before, int count) {
        // your code here
    }
});

And for the Spinners try this:

spinner1.setOnItemSelectedListener(new OnItemSelectedListener() {
    @Override
    public void onItemSelected(AdapterView<?> parentView, View selectedItemView, int position, long id) {
        // your code here
    }

    @Override
    public void onNothingSelected(AdapterView<?> parentView) {
        // your code here
    }
}

Answer 2

Have you checked the api documentation? All android views have pretty clear listener apis. EditText / TextView is no exception: addTextChangedListener

Spinners have: setOnItemSelectedListener