小编Bat*_*atu的帖子

我搜索了很多,但找不到GROUP BY查询的任何文档或示例.

现在,即使把RLMResults放在一个循环中也可以解决我的问题,但有一种优雅的方法吗？

我想用相机录制时播放音频文件.我使用AVAudioPlayer播放音频和AVCamCaptureManager进行录制.

但是当音频开始播放时,预览屏幕就会冻结.我该怎么办？

谢谢你的帮助.这是代码.(我正在研究AVCam的例子.)

这是预览部分.

if ([self captureManager] == nil) {
        AVCamCaptureManager *manager = [[AVCamCaptureManager alloc] init];
        [self setCaptureManager:manager];

        [[self captureManager] setDelegate:self];

        if ([[self captureManager] setupSession]) {             
            AVCaptureVideoPreviewLayer *newCaptureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:[[self captureManager] session]];
            UIView *view = [self videoPreviewView];
            CALayer *viewLayer = [view layer];
            [viewLayer setMasksToBounds:YES];

            CGRect bounds = CGRectMake(0, 0, 480, 320);
            [newCaptureVideoPreviewLayer setFrame:bounds];

            if ([newCaptureVideoPreviewLayer isOrientationSupported]) {
                [newCaptureVideoPreviewLayer setOrientation:[DeviceProperties setPreviewOrientation]];
            }

            [newCaptureVideoPreviewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];

            [viewLayer insertSublayer:newCaptureVideoPreviewLayer below:[[viewLayer sublayers] objectAtIndex:0]];

            [self setCaptureVideoPreviewLayer:newCaptureVideoPreviewLayer];
            dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
                [[[self captureManager] session] startRunning];
            }); …