直接在需要的activity中重寫onKeyDown方法
private long start = 0;
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_DOWN){
if ((System.currentTimeMillis()- startTime) > 2000){
Toast.makeText(getApplicationContext(),"再按一次退出程序",Toast.LENGTH_LONG).show();
startTime = System.currentTimeMillis();
} else {
finish();
System.exit(0);
}
return true;
}
return super.onKeyDown(keyCode, event);
}
