AVfoundation中焦距的设置(slider实现拉近拉远镜头) -自定义UISlider

焦距AVfoundation调节焦距
首先设置一个slider

UISlider focusSlider = [[UISlideralloc]initWithFrame:CGRectMake(60,_bottomView.frame.origin.y-60,200,20)];

[focusSlideraddTarget:selfaction:@selector(AdjustFocusAction:)forControlEvents:UIControlEventValueChanged];

[focusSlidersetThumbImage:[UIImageimageNamed:@"camera_view_slider_take_gray.png"]forState:UIControlStateNormal];

[focusSlidersetMinimumTrackImage:[UIImageimageNamed:@"camera_view_sliderbar_gray.png"]forState:UIControlStateNormal];

[focusSlidersetMaximumTrackImage:[UIImageimageNamed:@"camera_view_sliderbar_gray.png"]forState:UIControlStateNormal];

[focusSlidersetBackgroundColor:[UIColorclearColor]];

[focusSlidersetMaximumValue:1];

[focusSlidersetMinimumValue:0];

[focusSlider setValue:0.0];

[self.viewaddSubview:focusSlider];

以下做一下有关相机的设置（只写出来了其中一部分，并非全部）

preview = [AVCaptureVideoPreviewLayerlayerWithSession:self.session];

self.preview.frame =CGRectMake(0,0, self.cameraView.frame.size.width,self.cameraView.frame.size.height);

[self.previewsetPosition:CGPointMake(CGRectGetMidX(self.cameraView.bounds),CGRectGetMidY(self.cameraView.bounds))];

self.preview.videoGravity =AVLayerVideoGravityResize;

[self.cameraView.layeraddSublayer:self.preview];

captureOutput
= (AVCaptureStillImageOutput*)[self.session.outputsobjectAtIndex:0];

focusConnection =[captureOutput connectionWithMediaType:AVMediaTypeVideo];

调节焦距

-(void)AdjustFocusAction:(id)sender

{

[UIViewanimateWithDuration:0.025animations:^{

[self.previewsetAffineTransform:CGAffineTransformMakeScale([(UISlider
*)sendervalue]+1, [(UISlider *)sendervalue]+1)];

focusConnection.videoScaleAndCropFactor = [(UISlider *)sendervalue]+1;

}];

}