做人臉識別的項目中用到，順便做了下筆記

//上鎖

-(void)changeDevicePropertySafety:(void (^)(AVCaptureDevice *captureDevice))propertyChange{

??? AVCaptureDevice *captureDevice= [_videoInput device];
?
??? if ([captureDevice lockForConfiguration:nil]) {
??????? propertyChange(captureDevice);
??????? [captureDevice unlockForConfiguration];
??? }

}

//縮放的實現點擊

-(void)FocalLength{
??? NSLog(@"調整焦距");
??? [self changeDevicePropertySafety:^(AVCaptureDevice *captureDevice) {
????? if (captureDevice.videoZoomFactor == 1.0) {

????????????//縮放倍數

??????????? CGFloat current = 1.5;
??????????? if (current < captureDevice.activeFormat.videoMaxZoomFactor) {
??????????????? [captureDevice rampToVideoZoomFactor:current withRate:10];
??????????? }
??????? }else{

??????????? //1.0 表示縮放回到原來的大小（復原）

??????????? [captureDevice rampToVideoZoomFactor:1.0 withRate:10];
??????? }
??? }];
?? ?
}

總結

以上是生活随笔為你收集整理的AVCaptureDevice中通过调用VideoZoomFactor方法调整焦距实现拉近拉远镜头进行拍照录制视频（动画缩放画面，不闪屏）的全部內容，希望文章能夠幫你解決所遇到的問題。

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