QMUIImagePreviewViewControllerTransitioningStyle

NS_ENUM(NSUInteger, QMUIImagePreviewViewControllerTransitioningStyle) {
    /// present 时整个界面渐现，dismiss 时整个界面渐隐，默认。
    QMUIImagePreviewViewControllerTransitioningStyleFade,
    
    /// present 时从某个指定的位置缩放到屏幕中央，dismiss 时缩放到指定位置，必须实现 sourceImageView 并返回一个非空的值
    QMUIImagePreviewViewControllerTransitioningStyleZoom
}