using onBackPressed() with backward compatibility

问题

I want to use onBackPressed() method and still want to provide support for Android SDK before 2.0. onBackPressed() is introduced in Android SDK 2.0. but how to do ?

回答1:

Using onKeyDown;

public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK) {

          // Your Code Here

        return true;
    }
    return super.onKeyDown(keyCode, event);
}

回答2:

You may capture a key event and check for the back key. On your activity:

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if(keyCode == KeyEvent.KEYCODE_BACK){
        goBack();
        return true;
    }
    return super.onKeyDown(keyCode, event);
}

And write the goBack method to go where you need.

More at: Android - onBackPressed() not working

回答3:

Answer ---> http://apachejava.blogspot.com/2011/01/backward-compatibility-using.html

@Override
public boolean onKeyDown(int keyCode, KeyEvent event)  {
    if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.ECLAIR
            && keyCode == KeyEvent.KEYCODE_BACK
            && event.getRepeatCount() == 0) {
        // Take care of calling this method on earlier versions of
        // the platform where it doesn't exist.
        onBackPressed();
    }

    return super.onKeyDown(keyCode, event);
}

@Override
public void onBackPressed() {
    // This will be called either automatically for you on 2.0
    // or later, or by the code above on earlier versions of the
    // platform.
    return;
}

来源：https://stackoverflow.com/questions/4815127/using-onbackpressed-with-backward-compatibility

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android

sdk