为特定时间隐藏布局

Question

我正在构建应用程序。我想从上午8点到12点隐藏我的布局。我试过使用线程和asynctask，但我不明白如何在8到12之间给出时间段。

<LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
     <de.hdodenhof.circleimageview.CircleImageView
            android:layout_width="40dp"
            android:layout_height="50dp"
            android:layout_marginLeft="3dp"
            android:scaleType="centerCrop"
            android:src="@drawable/vegitables"
            app:civ_border_color="#80000000"
            app:civ_border_width="1dp" />
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:layout_marginLeft="5dp"
            android:text="Veg :"
            android:textColor="#F00"
            android:textSize="18sp"
            android:textStyle="bold" />
    </LinearLayout>
    <ListView
        android:id="@+id/list"
        android:layout_width="match_parent"
        android:layout_height="150dp"/>
</LinearLayout>

Answer 1

试试这个:

Calendar now = Calendar.getInstance();
int currentHour = now.get(Calendar.HOUR_OF_DAY);
if(currentHour >=7 && currentHour <= 11)
    rootLayoutReference.setVisibility(View.GONE);
else
    rootLayoutReference.setVisibility(View.VISIBLE);

Answer 2

首先，12 AM表示午夜，而12 PM表示中午。我以为你指的是中午，但这个解决方案可以很容易地更改为任何时间界限。

你可以添加以下内容到你的Activity:

public class MyActivity extends AppCompatActivity {
    private Handler handler;
    private View layout;
    private Runnable updateVisibilityCallback;
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.my_activity);
        handler = new Handler(Looper.getMainLooper());
        layout = findViewById(R.id.layout);
        updateVisibilityCallback = new Runnable() {
            @Override
            public void run() {
                updateTextVisibility();
            }
        };
    }
    @Override
    protected void onResume() {
        super.onResume();
        updateTextVisibility();
    }
    @Override
    protected void onPause() {
        super.onPause();
        handler.removeCallbacks(updateVisibilityCallback);
    }
    private void updateTextVisibility() {
        Calendar calendar = Calendar.getInstance();
        int hour = calendar.get(Calendar.HOUR_OF_DAY);
        if (8 <= hour && hour <= 11) {
            layout.setVisibility(View.GONE);
        } else {
            layout.setVisibility(View.VISIBLE);
        }
        handler.postDelayed(updateVisibilityCallback, getVisibilityUpdateDelay());
    }
    private long getVisibilityUpdateDelay() {
        Calendar rightNow = Calendar.getInstance();
        int hour = rightNow.get(Calendar.HOUR_OF_DAY);
        Calendar nextUpdate = Calendar.getInstance();
        nextUpdate.set(Calendar.MINUTE, 0);
        nextUpdate.set(Calendar.SECOND, 0);
        nextUpdate.set(Calendar.MILLISECOND, 0);
        if (hour < 8) {
            nextUpdate.set(Calendar.HOUR_OF_DAY, 8);
        } else if (hour < 12) {
            nextUpdate.set(Calendar.HOUR_OF_DAY, 12);
        } else {
            nextUpdate.add(Calendar.DATE, 1);
            nextUpdate.set(Calendar.HOUR_OF_DAY, 8);
        }
        return nextUpdate.getTimeInMillis() - rightNow.getTimeInMillis();
    }
}

每次当Activity对用户可见时(在onResume中)，您检查时间并更新布局的可见性。此外，您跟踪下一次更新应该发生的时间-您计算延迟到8:00或12:00，并使用Handler发布Runnable。当你的用户停止关注活动时，你就清除回调。