react-native - 我在连接多维数据集 react-native 中有错误

Question

我有这个错误： TypeError: undefined is not an object (evalating 'f.getUserMedia')

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CallingService.createVideoSession([218307,218308 ]).then(session => {
      this.setState({'session':session});
      // global.videoSession=session;
            CallingService.getUserMedia(session)
                .then(stream => {
         alert(stream)
          // global.localVideoStreamObtained=stream;
                    // global.userIsCalling=true;
                    CallingService.initiateCall(session);
                })
                .catch(err => {
                    alert("getUserMedia err" + err);
                });
        });

请帮我