private long mExitTime; @Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
//设置回退
if ((System.currentTimeMillis() - mExitTime) > 2000) {
Toast.makeText(this, "再按一次退出程序", Toast.LENGTH_SHORT).show();
mExitTime = System.currentTimeMillis();
} else {
this.finish();
}
return true;
}
return super.onKeyDown(keyCode, event);
}