Android MediaProjection 录屏方案

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已于 2023-04-22 20:47:58 修改 · 5.4k 阅读

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#android

于 2020-01-25 17:45:18 首次发布

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MediaProjection是Android5.0后提出的一套用于录制屏幕的API，无需root权限。与 MediaProjection协同的类有 MediaProjectionManager， MediaCodec等。

获取MediaProjection对象

申请权限

在使用 MediaPeojection相关API时，需要请求系统级录制屏幕权限，申请权限的方法如下：

//通过getSystemService获取MediaProjectionManager对象

mMediaProjectionManager = (MediaProjectionManager) getSystemService(MEDIA_PROJECTION_SERVICE);

Intent captureIntent = mMediaProjectionManager.createScreenCaptureIntent();

startActivityForResult(captureIntent, REQUEST_CODE);

在 onActivityResult方法中处理回调并初始化 MediaProjection对象

MediaProjection mMediaProjection = mMediaProjectionManager.getMediaProjection(resultCode, data);

MediaProjectionManager获取过程

通过 context.getSystemService(MEDIA_PROJECTION_SERVICE)获取 MediaProjectionManager的详细流程：

Context#getSystemSevice

public abstract @Nullable Object getSystemService(@ServiceName @NonNull String name);

ContextImpl#getSystemService

@Override

public Object getSystemService(String name) {

return SystemServiceRegistry.getSystemService(this, name);

}

SystemServiceRegistry#getSystemService

private static final HashMap<String, ServiceFetcher<?>> SYSTEM_SERVICE_FETCHERS =

new HashMap<String, ServiceFetcher<?>>();

/**

* Statically registers a system service with the context.

* This method must be called during static initialization only.

*/

private static <T> void registerService(String serviceName, Class<T> serviceClass,

ServiceFetcher<T> serviceFetcher) {

SYSTEM_SERVICE_NAMES.put(serviceClass, serviceName);

SYSTEM_SERVICE_FETCHERS.put(serviceName, serviceFetcher);

}

registerService(Context.MEDIA_PROJECTION_SERVICE, MediaProjectionManager.class,

new CachedServiceFetcher<MediaProjectionManager>() {

@Override

public MediaProjectionManager createService(ContextImpl ctx) {

return new MediaProjectionManager(ctx);

}});