Android 在特定 Activity 之上启动 Activity

Question

假设我有以下 Activity

Activity A, Activity B, Activity C and Activity D

当前堆栈有以下条目

Activity C
Activity B
Activity A

我必须启动Activity D，以便堆栈变得如下所示，

Activity D
Activity A

我必须设置什么标志？

Answer 1

考虑使用A作为调度程序。当您想要从 C 启动 D 并在此过程中完成 C 和 B 时，请在 中执行此操作>C:

// Launch A (our dispatcher)
Intent intent = new Intent(this, A.class);
// Setting CLEAR_TOP ensures that all other activities on top of A will be finished
//  and setting SINGLE_TOP ensures that a new instance of A will not
//  be created (the existing instance will be reused and onNewIntent() will be called)
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP|Intent.FLAG_ACTIVITY_SINGLE_TOP);
// Add an extra telling A that it should launch D
intent.putExtra("startD", true);
startActivity(intent);

在A.onNewIntent()中执行以下操作:

@Override
protected void onNewIntent(Intent intent) {
    if (intent.hasExtra("startD")) {
        // Need to start D from here
        startActivity(new Intent(this, D.class));
    }
}