Android 如何在没有 UI 的情况下启动 Activity？
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原文地址: http://stackoverflow.com/questions/2704084/
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How to launch an Activity without a UI?
提问by fjmustak
Is it in any way possible to launch an activity from the main function without having a UI? i.e. is there a way to create a sort of "wrapper" around another activity, i.e. by launching the main activity, it takes you to another activity automatically.
是否可以在没有 UI 的情况下从主功能启动活动？即有没有办法围绕另一个活动创建一种“包装器”，即通过启动主要活动，它会自动将您带到另一个活动。
If that is not possible, is there a way to remove the main activity from the stack so that clicking the back button does not take you to a blank UI? Here's an example of what I'm trying to do:
如果这是不可能的，有没有办法从堆栈中删除主要活动，以便单击后退按钮不会将您带到空白 UI？这是我正在尝试做的一个例子：
public class WrapperActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
final Intent intent = new Intent(Intent.ACTION_DIAL, Uri.parse("tel:555-1212"));
startActivity(intent);
}
}
采纳答案by Vishwanath
You need to add the Intent flag,
您需要添加 Intent 标志，
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
Or
或者
call "finish();" after firing the intent.
finish();在触发意图后调用“ ”。
回答by Justin
Android also provides a theme specifically for this:
Android 还专门为此提供了一个主题：
android:theme="@android:style/Theme.NoDisplay"
回答by strange quark
In your manifest, when you declare the activity, use theme "@android:style/Theme.Translucent.NoTitleBar"
在您的清单中，当您声明活动时，请使用主题 "@android:style/Theme.Translucent.NoTitleBar"
Ex:
前任：
<activity android:name="yourActivityName" android:label="@string/app_name" android:theme="@android:style/Theme.Translucent.NoTitleBar">
回答by arunwithasmile
Just in case you are using Android 6.0+ or Target SDK is 23+, having a theme android:theme = "@android:style/Theme.NoDisplay"will lead to a crash with error did not call finish() prior to onResume() completing. This in fact is a bug recognised by Google developers here.
以防万一您使用的是 Android 6.0+ 或 Target SDK 是 23+，拥有主题android:theme = "@android:style/Theme.NoDisplay"会导致崩溃并出现错误did not call finish() prior to onResume() completing。这实际上是 Google 开发人员在此处承认的错误。
So it is recommended to use an activity with following theme as a workaround.
因此，建议使用具有以下主题的活动作为解决方法。
android:theme = "@android:style/Theme.Translucent.NoTitleBar"
android:theme = "@android:style/Theme.Translucent.NoTitleBar"
回答by Tmac
Using
使用
<activity android:name="yourActivityName" android:label="@string/app_name" android:theme="@android:style/Theme.Translucent.NoTitleBar">
mentioned by Brian515 works great. This method is useful for creating an entry point Activity that decides on which activity to call, start, services, etc without having to show a UI to the user. Remember to use finish()after you have started your intent.
Brian515 提到的效果很好。此方法对于创建一个入口点 Activity 非常有用，该入口点 Activity 决定要调用、启动、服务等的 Activity，而无需向用户显示 UI。请记住finish()在开始意图后使用。
回答by Fermin Genao
I think this would help you a lot:
我认为这会对你有很大帮助：
<activity android:name = "MyActivity"
android:label = "@string/app_name"
android:theme = "@android:style/Theme.NoDisplay" >
回答by Vipul Behl
In your manifest add @android:style/Theme.Translucent.NoTitleBar"as mentioned in some of the answers above.
在您的清单中添加@android:style/Theme.Translucent.NoTitleBar"上面一些答案中提到的内容。
Also remove the setContentView(R.layout.your_activity);line from your activity.java file.
同时setContentView(R.layout.your_activity);从您的 activity.java 文件中删除该行。
回答by Sreedevi J
Looks similar to the question asked here: Removing an activity from the history stack
看起来类似于这里提出的问题：Removing an activity from the history stack
If it is, then you can use:
如果是，那么您可以使用：
FLAG_ACTIVITY_NO_HISTORY
FLAG_ACTIVITY_NO_HISTORY
This should work to wipe activities off of the stack.
这应该可以清除堆栈中的活动。
If you need to exclude from recent apps (long press home key) you can use this flag:
如果您需要从最近的应用程序中排除（长按主页键），您可以使用此标志：
FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS
FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS
回答by sfratini
If you are not interacting with the UI, what you are trying to do sounds more like an android service.
如果您不与 UI 交互，那么您尝试做的事情听起来更像是一个 android 服务。
回答by Tarak
I had used moveTaskToBack(true)in onResume()to put the entire activity stack in background.
我曾用moveTaskToBack(true)在onResume()把整个活动堆栈的背景。
