ios - 如何使用 if/else 条件来切换手电筒？

Question

所以我有一个用于覆盖层的 UISwitch，每次相机出现时都会出现。现在，当我切换打开按钮或将开关滑动到右侧(打开模式)时，手电筒就会打开。但是当我将其切换到左侧时，它不会关闭。我做错了什么？

- (void)mySwitchPressed {
    if (self.mySwitch.on) { 
        AVCaptureDevice *flashLight = [AVCaptureDevice
        defaultDeviceWithMediaType:AVMediaTypeVideo];
        if([flashLight isTorchAvailable] && [flashLight
            isTorchModeSupported:AVCaptureTorchModeOn]) {
            BOOL success = [flashLight lockForConfiguration:nil];
            if(success) {
                [flashLight setTorchMode:AVCaptureTorchModeOn];
                [flashLight unlockForConfiguration];
            }
        } else {
            AVCaptureDevice *flashLight = [AVCaptureDevice
            defaultDeviceWithMediaType:AVMediaTypeVideo];
            if([flashLight isTorchAvailable] && [flashLight 
                isTorchModeSupported:AVCaptureTorchModeOn]) {
                BOOL success = [flashLight lockForConfiguration:nil];
                if(success) {
                    [flashLight setTorchMode:AVCaptureTorchModeOff];
                    [flashLight unlockForConfiguration];
                }
            }
        }
    }
}

Answer 1

重新格式化您的代码后，您的 else 子句似乎位于错误的位置。尝试将 else 移至第一个 if block 末尾之后:

- (void)mySwitchPressed {
    if (self.mySwitch.on) { 
        AVCaptureDevice *flashLight = [AVCaptureDevice
        defaultDeviceWithMediaType:AVMediaTypeVideo];
        if([flashLight isTorchAvailable] && [flashLight
            isTorchModeSupported:AVCaptureTorchModeOn]) {
            BOOL success = [flashLight lockForConfiguration:nil];
            if(success) {
                [flashLight setTorchMode:AVCaptureTorchModeOn];
                [flashLight unlockForConfiguration];
            }
        }
    } else {
        AVCaptureDevice *flashLight = [AVCaptureDevice
        defaultDeviceWithMediaType:AVMediaTypeVideo];
        if([flashLight isTorchAvailable] && [flashLight 
            isTorchModeSupported:AVCaptureTorchModeOn]) {
            BOOL success = [flashLight lockForConfiguration:nil];
            if(success) {
                [flashLight setTorchMode:AVCaptureTorchModeOff];
                [flashLight unlockForConfiguration];
            }
        }
    }
}