ios - 如何将 Objective-C block 转换为 Swift 闭包？

Question

我有来自 Github 的以下 Objective-C block 分配示例 dzenbot/DZNPhotoPickerController我正在努力转换为 Swift。 Controller 是一个 UIImagePickerController。

controller.finalizationBlock = ^(UIImagePickerController *picker, NSDictionary *info) {

    UIImage *image = info[UIImagePickerControllerEditedImage];
    weakSelf.imageView.image = image;

    // Dismiss when the crop mode was disabled
    if (picker.cropMode == DZNPhotoEditorViewControllerCropModeNone) {
        [weakSelf dismissController:picker];
    }
};

我尝试了以下方法，但无法弄清楚我哪里出了问题。

controller.finalizationBlock = { (picker: UIImagePickerController, info: NSDictionary) -> UIImagePickerControllerFinalizationBlock! in
        var image = UIImagePickerControllerEditedImage(info)
        imageView.image = image

        // Dismiss when the crop mode was disabled
        if (picker.cropMode == .None) {
            dismissEditor(picker)
        }
    }

我得到的错误是:

"Cannot assign value of type '(UIImagePickerController, NSDictionary) -> UIImagePickerControllerFinalizationBlock!' to type 'UIImagePickerControllerFinalizationBlock!'

Answer 1

Objective-C block 不返回任何内容，因此其闭包应如下所示:

controller.finalizationBlock = { (picker, info) in
        var image = UIImagePickerControllerEditedImage(info)
        imageView.image = image

        // Dismiss when the crop mode was disabled
        if (picker.cropMode == .None) {
            dismissEditor(picker)
        }
    }