在Android Studio按Back返回键执行返回指定页面和线程销毁任务
先建立一个Back键的自动运行任务
@Override
public void onBackPressed() {
}
这里以关闭mqtt线程并返回MainActivity页为例:
@Override
public void onBackPressed() {
try {
androidClient.disconnect();
} catch (MqttException e) {
e.printStackTrace();
}
Intent intent = new Intent(Yaokong.this, MainActivity.class);
startActivity(intent);
}
按back键退出程序时,实现“再按一次退出”的功能
下面代码源自 https://blog.csdn.net/lwcumt/article/details/46422297
long startTime = 0;
@Override
public void onBackPressed() {
long currentTime = System.currentTimeMillis();
if ((currentTime - startTime) >= 2000) {
Toast.makeText(MainActivity.this, "再按一次退出", Toast.LENGTH_SHORT).show();
startTime = currentTime;
} else {
finish();
}
}