檢查是否任何AV設備連接

Question

我有這個代碼假定一個AV決定的，是連接...

AVCaptureDeviceInput *device_input = [[AVCaptureDeviceInput alloc] initWithDevice : 
               [AVCaptureDevice devicesWithMediaType : AVMediaTypeVideo][0] error : nil]; 

我如何修改代碼，使我得到這樣的消息...

if (No AV devices were detected) 
NSLog(@"No AV devices were detected"); 
else 
NSLog(@"The following devices were detected..."); 

謝謝， Len。

Answer 1

如果你有檢查音頻設備，你可以使用下面代碼 -

-(void)checkForDevice{ 
    AVCaptureDevice *audioDevice = [[AVCaptureDevice devicesWithMediaType:AVMediaTypeAudio] firstObject]; 
    AVCaptureDeviceInput *audioDeviceInput = [AVCaptureDeviceInput deviceInputWithDevice:audioDevice error:&error]; 

    if (error) 
    { 
     NSLog(@"%@", error); //problem with the device 
    } 
    else 
    { 
     //device is available 
    } 
} 

在類似的方式，你可以檢查錄象和其他視聽設備。