Question

所以我认为我在主线程上有startDeviceMotionUpdatesToQueue，但显然情况并非如此，因为我应该在NSLogs之后获得NSLog更新。

2017-03-26 14:01:40.422661 Pneumonia Diagnosing App[950:200771] File 
accel.wav being overwritten...
...
2017-03-26 14:01:40.617392 Pneumonia Diagnosing App[950:200771] j=229320, finalfilelength = 229320, and i=114704, and filelength = 114660
2017-03-26 14:01:40.622864 Pneumonia Diagnosing App[950:200771] number: 66 Accelval: 0.004889
2017-03-26 14:01:40.623466 Pneumonia Diagnosing App[950:200771] number: 67 Accelval: 0.005058

我设置了startDeviceMotionUpdatesToQueue，如下所示：

[motionManager startDeviceMotionUpdatesToQueue:[NSOperationQueue mainQueue] withHandler:^(CMDeviceMotion *deviceMotion, NSError *error) {
        CMAcceleration userAcceleration = deviceMotion.userAcceleration;
        float accelval = userAcceleration.y*9.81;
        count = count + 1;
        NSString *accelvalue = [[NSString alloc] initWithFormat:@"%f\n",accelval];
        //NSLog(@"number: %d Accelval: %f",count, accelval);
        NSFileHandle *myHandle;
        myHandle = [NSFileHandle fileHandleForWritingAtPath:filePath];
        [myHandle seekToEndOfFile];
        [myHandle writeData:[accelvalue dataUsingEncoding:NSUTF8StringEncoding]];
        [myHandle closeFile];
    }];

我相信mainQueue是主线程。

在我的代码中，我希望将加速度计值记录到csv中，然后经过大量处理后，我希望将它们放入wav文件中。

在startDeviceMotionUpdatesToQueue块之后（通过点击记录按钮发生），点击停止按钮并发生这种情况：

[motionManager stopDeviceMotionUpdates];
        [recordbuttonimage setImage:[UIImage imageNamed:@"record.png"] forState:UIControlStateNormal];
    recordbuttonstatus=0;
    playbuttonimage.enabled=TRUE;
    [playbuttonimage setImage:[UIImage imageNamed:@"play.png"] forState:UIControlStateNormal];
    [recorder stop];
        // Process CSV File on new Thread
        [self prepareaccelvalsforwav];
        // Combine data channels
        [self combinechannels];

记录应该出现的行的代码发生在combine渠道方法中，我在下面分享了一些代码。

创建wav后，我有日志告诉我wav中字节的索引和文件的音频长度：

FILE *finaldata = fopen([finalaudiofilepath UTF8String], "ab");
                                       i=44;
                                   k=4096;
                                   j=0;
                                       for (j = 0; j < (mixedaudiobufferlength);) {
                                           buffer3[0] = audiobytedatabuffer[k];
                                           buffer3[1] = audiobytedatabuffer[k + 1];
                                           buffer3[2] = accelbytedatabuffer[i];
                                           buffer3[3] = accelbytedatabuffer[i + 1];

                                           j = j + 4;
                                           i = i + 2;
                                           k = k + 2;
                                           fwrite(buffer3,1,4,finaldata);
                                           fflush(finaldata);
                                       }
                                   NSLog(@"j=%d, finalfilelength = %d, and i=%d, and filelength = %llu",j,mixedaudiobufferlength,i,accelfileSize);
                                       fclose(finaldata);

您可以在我发布的日志中看到。然而，加速度计NSLog再次弹出。我该怎么做才能防止这种情况，让加速度计在写入wav文件之前停止记录值？

为什么NSLog无序？

0 个答案: