相机相关备注

获取 AVCaptureSession

在获取

- (AVCaptureDevice*)backCamera

{

NSArray*devices = [AVCaptureDevicedevicesWithMediaType:AVMediaTypeVideo];

for(AVCaptureDevice*deviceindevices) {

if(device.position==AVCaptureDevicePositionBack) {

returndevice;

}

}

returnnil;

}

[_avSessionbeginConfiguration];

_avSession.sessionPreset=AVCaptureSessionPreset640x480;

//通过capture对象创建输入设备对象

NSError*error =nil;

_backCameraDevice= [selfbackCamera];

[_backCameraDevicelockForConfiguration:&error];

//_backCameraDevice.focusMode = AVCaptureFocusModeLocked;

[_backCameraDeviceunlockForConfiguration];

[_avSessioncommitConfiguration];

[_backCameraDevice setFocusModeLockedWithLensPosition:slider.value completionHandler:nil]; 此方法是设置对焦，position为0到1；

[_backCameraDevicelockForConfiguration:&error];

_backCameraDevice.videoZoomFactor= sender.value; 此方法可以实现镜头放大缩小，最小为1.0

[_backCameraDeviceunlockForConfiguration];