在Windows、iOS和Android设备上实现屏幕共享_视频直播(LIVE)-阿里云帮助中心

阿里云基于ARTC SDK在不同设备（Windows、iOS和Android）上实现了屏幕共享的相关功能，本篇文档详细介绍了如何使用ARTC SDK通过少量的代码实现屏幕共享。

方案概览

主播在视频直播时可能会有屏幕共享的需求，阿里云ARTC SDK提供了屏幕分享的最佳实践，开发者可以调用ARTC SDK的相关API实现屏幕共享。您可以通过少量的代码实现屏幕分享，现在ARTC SDK支持Windows、iOS和Android设备。

接下来我们通过Windows、iOS和Android的顺序详细的介绍如何使用ARTC SDK快速实现屏幕共享。

一、Windows

1.屏幕共享

1.1 打开屏幕共享

/*
* 共享屏幕局部
*/
      RECT rc;
      ::GetWindowRect(::GetDesktopWindow(), &rc);

      AliEngineScreenShareRegion screenRegion;
      screenRegion.originX = (float)rc.left;
      screenRegion.originY = (float)rc.top;
      screenRegion.width = (float)(rc.right - rc.left);
      screenRegion.height = (float)(rc.bottom - rc.top);

      AliEngineScreenShareConfig config;

      config.isShareByRegion = false;
      config.shareRegion = screenRegion;
      
      mpEngine->StartScreenShareByScreenRegion(screenRegion, config);

1.2 停止屏幕共享

mpEngine->StopScreenShare();

2.多窗口共享

2.1 枚举所有可共享的窗口或者桌面

/*
 mScreenShareType可赋值为AliEngineScreenShareDesktop或者AliEngineScreenShareWindow
 分别代表桌面与窗口。
*/

mScreenShareType = AliEngineScreenShareDesktop ;//(或 mScreenShareType = AliEngineScreenShareWindow ; )

/*
 mSourceId 上次选中的id，下面代码是填充一个comboBox列表
*/

mCurrentSourceList = mEngine->GetScreenShareSourceInfo(mScreenShareType);
  if (nullptr != mCurrentSourceList)
  {
      for (size_t i = 0; i < mCurrentSourceList->GetCount(); i++) {
        AliEngineScreenSourcInfo info = mCurrentSourceList->GetSourceInfo(i);

        /*
        * 如果不希望共享APP自身窗口，可以通过sourceIsSelf来区分
        */
        info.sourceIsSelf 
        CString s = AliStringToCString(info.sourceName);
        lb->AddString(s);
        if (mSourceId == info.sourceId) {
          lb->SetCurSel(i);
        }
      }
      
      /*
      * 默认选择第一个窗口或者桌面，记录ID和窗口名
      */
      if (mSourceId.isEmpty() && lb->GetCount() > 0)
      {
        lb->SetCurSel(0);
        AliEngineScreenSourcInfo info = mCurrentSourceList->GetSourceInfo(0);
        mSourceId = info.sourceId;
        mSourceTitle = info.sourceName;
      }
  }

2.2 共享对应的窗口或者桌面

msSourceId是共享桌面的ID，可以通过上文的枚举接口获取；
screenShareSource是配置；

AliEngineScreenShareRegion  shareRegion ;
shareRegion.originX = 0.f;
shareRegion.originY = 0.f;
shareRegion.width = 640.f;
shareRegion.height = 480.f;
            
screenShareSource.isShareByRegion = true ;
screenShareSource.shareRegion =  shareRegion;

/*
* 共享桌面
*/
mpEngine->StartScreenShareByDesktopId(atol(msSourceId.c_str()), screenShareSource);

/*
* 共享窗口
*/
mpEngine->StartScreenShareByWindowId(atol(msSourceId.c_str()), screenShareSource);

/*
* 可以显示获取共享窗口的显示范围
*/
AliEngineScreenShareRegion region;
		mEngine->GetDesktopRegion(mSourceId, mSourceTitle, region);
		CString resolutionMsg;
		resolutionMsg.Format(_T("Resolution: %d x %d"), region.width, region.height);
		((CStatic*)GetDlgItem(IDC_STATIC_SCREEN_SOURCE_RESOLUTION))->SetWindowTextW(resolutionMsg);
		((CEdit*)GetDlgItem(IDC_EDIT_SHARE_REGION_X))->SetWindowTextW(std::to_wstring(mScreenShareSource.shareRegion.originX).c_str());
		((CEdit*)GetDlgItem(IDC_EDIT_SHARE_REGION_Y))->SetWindowTextW(std::to_wstring(mScreenShareSource.shareRegion.originY).c_str());
		((CEdit*)GetDlgItem(IDC_EDIT_SHARE_REGION_X2))->SetWindowTextW(std::to_wstring(mScreenShareSource.shareRegion.width).c_str());
		((CEdit*)GetDlgItem(IDC_EDIT_SHARE_REGION_Y2))->SetWindowTextW(std::to_wstring(mScreenShareSource.shareRegion.height).c_str());
	}

2.3 停止共享对应的窗口或者桌面

mpEngine->StopScreenShare();

二、iOS

1.接入方式

iOS接入屏幕共享需要在原宿主 App 的基础上新建 App Extension, 并在 App Extension 中依赖 AliScreenShare.framework。
在宿主 APP 当中 embed 新建的 App Extension, 并且设置相同的 App Groups, 如果在原宿主 App 当中没有设置 App Groups, 需要在宿主 App 的 profile 当中新建 App Groups 选项。
宿主 App 和 App Extension 需要保持相同的 Bundle Id 前缀, 并使用同样的开发证书进行签名。

2.共享窗口/系统音频

    AliRtcScreenShareMode mode = AliRtcScreenShareNone;

 /*
 * 根据需要选择性设置是否共享音频
 */
    if (ctrl.shareVideo) {
      mode |= AliRtcScreenShareVideo;
    }
    
    if (ctrl.shareAudioApp) {
      mode |= AliRtcScreenShareAudioApp;
    }
    
    [strongSelf.engine startScreenShare:kAppGroup mode:mode];
    [strongSelf.engine setAudioShareAppVolume:ctrl.appPublishVolume];

3.停止共享窗口和音频

[strongSelf.engine stopScreenShare];

4.改变设置

/* 值改变，调用相关接口 */
if (ctrl.enablePublishScreenTrackConfig) {
   [strongSelf.engine setPublishVideoStreamAttribute:AliRtcVideoTrackScreen attr:@"range=mpu"];
} else {
    [strongSelf.engine setPublishVideoStreamAttribute:AliRtcVideoTrackScreen attr:@""];
}

/* 停止推流，才能重新repub屏幕流 */
[strongSelf.engine stopScreenShare];

AliRtcScreenShareMode mode = AliRtcScreenShareNone;

if (ctrl.shareVideo) {
   mode |= AliRtcScreenShareVideo;
}

if (ctrl.shareAudioApp) {
   mode |= AliRtcScreenShareAudioApp;
}

[strongSelf.engine startScreenShare:kAppGroup mode:mode];
[strongSelf.engine setAudioShareAppVolume:ctrl.appPublishVolume];

三、Android

1.共享窗口/系统音频

if (config.permitScreen && config.permitAudioShare) {
    mScreenShareMode = AliRtcEngine.AliRtcScreenShareMode.AliRtcScreenShareAllMode;
} else if (config.permitScreen) {
    mScreenShareMode = AliRtcEngine.AliRtcScreenShareMode.AliRtcScreenShareOnlyVideoMode;
} else if (config.permitAudioShare) {
    mScreenShareMode = AliRtcEngine.AliRtcScreenShareMode.AliRtcScreenShareOnlyAudioMode;
}
      
mAliRtcEngine.startScreenShare(null, mScreenShareMode);

2.停止共享窗口和音频

pubScreenCaptureResult = mAliRtcEngine.stopScreenShare();