从源码看Activity启动过程(三)AMS-ActivityThread/ApplicationThread-实例化Activity

最新推荐文章于 2024-08-26 19:14:05 发布

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最新推荐文章于 2024-08-26 19:14:05 发布 · 689 阅读

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#Activity启动过程

1、ActivityThread源码解析

public final class ActivityThread {
	//一些重要变量
	final ApplicationThread mAppThread = new ApplicationThread();
    final Looper mLooper = Looper.myLooper();
	//这个mH就是当前进程UI线程的handler，处理接收到的消息，比如四大组件生命周期方法的调用等
    final H mH = new H();
	//当前进程的所有activity数据都会封装成ActivityClientRecord放入mActivities
    final ArrayMap<IBinder, ActivityClientRecord> mActivities = new ArrayMap<>();
	ArrayList<WeakReference<AssistStructure>> mLastAssistStructures = new ArrayList<>();
	final ArrayMap<IBinder, Service> mServices = new ArrayMap<>();
    AppBindData mBoundApplication;
    Profiler mProfiler;
    int mCurDefaultDisplayDpi;
    boolean mDensityCompatMode;
    Configuration mConfiguration;
    Configuration mCompatConfiguration;
    Application mInitialApplication;
    final ArrayList<Application> mAllApplications = new ArrayList<Application>();
    // set of instantiated backup agents, keyed by package name
    final ArrayMap<String, BackupAgent> mBackupAgents = new ArrayMap<String, BackupAgent>();
    /** Reference to singleton {@link ActivityThread} */
    private static volatile ActivityThread sCurrentActivityThread;
    Instrumentation mInstrumentation;	
	...
	//main方法
	public static void main(String[] args) {
        Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "ActivityThreadMain");
        SamplingProfilerIntegration.start();
        CloseGuard.setEnabled(false);

        Environment.initForCurrentUser();

        // Set the reporter for event logging in libcore
        EventLogger.setReporter(new EventLoggingReporter());

        // Make sure TrustedCertificateStore looks in the right place for CA certificates
        final File configDir = Environment.getUserConfigDirectory(UserHandle.myUserId());
        TrustedCertificateStore.setDefaultUserDirectory(configDir);

        Process.setArgV0("<pre-initialized>");

        Looper.prepareMainLooper();

        ActivityThread thread = new ActivityThread();
        thread.attach(false);

        if (sMainThreadHandler == null) {
            sMainThreadHandler = thread.getHandler();