如何在UIAlertController中添加UIImageView？

Question

我想UIAlertController与提出警告UIImageView在ActionSheet.但是,当我运行应用程序时,它正在终止.

这是我的代码:

UIAlertController *alert = [UIAlertController
                                  alertControllerWithTitle:@"Title"
                                  message:@"Welcome"
                                  preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *okButton = [UIAlertAction
                            actionWithTitle:OK
                            style:UIAlertActionStyleDefault
                            handler:^(UIAlertAction *action)
                            {
                            }];
[alert addAction:okButton];
UIImageView *imgv = [[UIImageView alloc]initWithFrame:CGRectMake(20,20,50,50)];
imgv.image = [UIImage imageNamed:@"kaga.jpg"];
[alert setValue:imgv forKey:@"image"];
[self presentViewController:alert animated:YES completion:nil];

Answer 1

您可以通过子类化添加图像在标题标签上方,UIAlertController并添加\n到标题字符串以为其创建空间UIImageView.您必须根据字体大小计算布局.对于UIAlertAction使用中的图像KVC如此:self.setValue(image, forKey: "image").我建议使用检查的扩展名responds(to:).

这是示例实现.

extension UIAlertAction {

    /// Image to display left of the action title
    var actionImage: UIImage? {
        get {
            if self.responds(to: Selector(Constants.imageKey)) {
                return self.value(forKey: Constants.imageKey) as? UIImage
            }
            return nil
        }
        set {
            if self.responds(to: Selector(Constants.imageKey)) {
                self.setValue(newValue, forKey: Constants.imageKey)
            }
        }
    }

    private struct Constants {
        static var imageKey = "image"
    }
}

Answer 2

UIAlertController根据Apple Doc，无法将图像添加到中。

如果需要，可以创建自己的自定义视图，例如：

https://github.com/wimagguc/ios-custom-alertview

如果您想拍摄图像，button 请尝试如下操作：

UIAlertController * alert = [UIAlertController alertControllerWithTitle:@"Title"
                              message:@"Welcome"
                              preferredStyle:UIAlertControllerStyleActionSheet];

UIAlertAction* okButton = [UIAlertAction actionWithTitle:@"OK"
                            style:UIAlertActionStyleCancel
                            handler:^(UIAlertAction * action) {
                              //Do some thing here
                            }];

[okButton setValue:[[UIImage imageNamed:@"kaga.jpg"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal] forKey:@"image"];

[alert addAction:okButton];
[self presentViewController:alert animated:YES completion:nil];