iOS：AVFoundation：焦点

Question

自动对焦完成后，是否有办法随时获得对焦点？

在Apple的示例代码中，他们使用：

    - (void)subjectAreaDidChange:(NSNotification *)notification

{

     CGPoint devicePoint = CGPointMake(.5, .5);

     [self focusWithMode:AVCaptureFocusModeContinuousAutoFocus exposeWithMode:AVCaptureExposureModeContinuousAutoExposure atDevicePoint:devicePoint monitorSubjectAreaChange:NO];

}

以上代码仅适用于“点击以关注”。它还会强制相机对焦在屏幕中央。我想在自动对焦完成后立即获得对焦点。

Answer 1

看起来您只需阅读focusPointOfInterest属性即可获得当前焦点：

- (void)subjectAreaDidChange:(NSNotification *)notification
{
     CGPoint devicePoint = device.focusPointOfInterest;
}