在TextWatcher中检测退格 [英] Detect backspace in TextWatcher

问题描述

我正在使用TextWatcher，并且无法检测到TextWatcher.afterTextChange事件中的 Backspace 键.我还想在textWatcher事件中的某些情况下清除textView.

I am using TextWatcher and I am unable to detect Backspace key in TextWatcher.afterTextChange event. I also want to clear textView on some condition in textWatcher event.

public void afterTextChanged(Editable s) {
    // TODO Auto-generated method stub
    // I want to detect backspace key here
}

推荐答案

KeyListener可以满足您的两个条件.

A KeyListener can fulfil both of your conditions.

mEditText.setOnKeyListener(new OnKeyListener() {                 
    @Override
    public boolean onKey(View v, int keyCode, KeyEvent event) {
           if(keyCode == KeyEvent.KEYCODE_DEL){  
             //on backspace
             }
    return false        
        }
});

类似地，在onKey()内，当您想清除textView时，可以放置多个检查语句以检查条件.

Similarly inside the onKey(), you can put multiple check statements to check for the condition, when you would want to clear the textView.

由于 @RankoR 足以指出，请记住 onKeyListener()仅适用于硬件键盘而不是软键盘.

EDIT : As @RankoR was kind enough to point out, please bear in mind that onKeyListener() works only for the hardware keyboards and not the soft keyboards.

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