向UIAlertView添加活动指示器

Question

我正在尝试将UIActivityIndicatorView添加到UIAlertView中，但无法完成。我已经看到了有关此实现的帖子，并发现它仅适用于iOS7以下版本。

以下是我尝试过的代码...

var alert: UIAlertView = UIAlertView(title: "Title", message: "Please wait...", delegate: nil, cancelButtonTitle: "Cancel");

var loadingIndicator: UIActivityIndicatorView = UIActivityIndicatorView(frame: CGRectMake(0.0, 0.0, 10.0, 10.0)) as UIActivityIndicatorView
loadingIndicator.center = self.view.center;
loadingIndicator.hidesWhenStopped = true
loadingIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.Gray
loadingIndicator.startAnimating();

alert.addSubview(loadingIndicator);  
alert.show();

针对iOS7及以上的版本，是否有特定的事情需要做才能完成这项任务？

- Srujan Simha

---

你可能也会对这个类感兴趣：https://github.com/goktugyil/CozyLoadingActivity - Esqarrouth

Answer 1

试试这段代码!!

var alert: UIAlertView = UIAlertView(title: "Title", message: "Please wait...", delegate: nil, cancelButtonTitle: "Cancel")


var loadingIndicator: UIActivityIndicatorView = UIActivityIndicatorView(frame: CGRect(x: 50, y: 10, width: 37, height: 37)) as UIActivityIndicatorView
loadingIndicator.center = self.view.center
loadingIndicator.hidesWhenStopped = true
loadingIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.Gray
loadingIndicator.startAnimating();

alert.setValue(loadingIndicator, forKey: "accessoryView")
loadingIndicator.startAnimating()

alert.show();

我希望我能帮助了你

- Beslan Tularov

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一个非常简短、非常好的解决方案，而且不建议使用 pod。你应该得到天堂里的一个特殊位置。 - Jochen Österreicher

使用了旧的方法/API，所以这段代码无法在Swift 5+中工作。UIAlertView在iOS 9.0中已被弃用。 - falsecrypt

setValue:forUndefinedKey - 立即崩溃。 - dub

Answer 2

对于 Swift 4 创建一个警告控制器扩展

extension UIAlertController {

    private struct ActivityIndicatorData {
        static var activityIndicator = UIActivityIndicatorView(frame: CGRect(x: 0, y: 0, width: 40, height: 40))
    }

    func addActivityIndicator() {
        let vc = UIViewController()
        vc.preferredContentSize = CGSize(width: 40,height: 40)
        ActivityIndicatorData.activityIndicator.color = UIColor.blue
        ActivityIndicatorData.activityIndicator.startAnimating()
        vc.view.addSubview(ActivityIndicatorData.activityIndicator)
        self.setValue(vc, forKey: "contentViewController")
    }

    func dismissActivityIndicator() {
        ActivityIndicatorData.activityIndicator.stopAnimating()
        self.dismiss(animated: false)
    }
}

在您的视图控制器中创建一个名为ctivityIndicatorAlert的Var，并像以下示例代码一样编写display和dismiss方法。

var activityIndicatorAlert: UIAlertController?

func displayActivityIndicatorAlert() {
    activityIndicatorAlert = UIAlertController(title: NSLocalizedString("Loading", comment: ""), message: NSLocalizedString("PleaseWait", comment: "") + "...", preferredStyle:  UIAlertController.Style.alert)
    activityIndicatorAlert!.addActivityIndicator()
    var topController:UIViewController = UIApplication.shared.keyWindow!.rootViewController!
    while ((topController.presentedViewController) != nil) {
        topController = topController.presentedViewController!
    }
    topController.present(activityIndicatorAlert!, animated:true, completion:nil)
}

func dismissActivityIndicatorAlert() {
    activityIndicatorAlert!.dismissActivityIndicator()
    activityIndicatorAlert = nil
}

你也可以添加UIViewcontroller的扩展，使其在全局上可用于所有方法。

extension UIViewController {
    private struct activityAlert {
        static var activityIndicatorAlert: UIAlertController?
    }
    //completion : ((Int, String) -> Void)?)
    func displayIPActivityAlert(_ onCancel : (()-> Void)?) {
        activityAlert.activityIndicatorAlert = UIAlertController(title: NSLocalizedString("Loading...", comment: ""), message: nil , preferredStyle: UIAlertController.Style.alert)
        activityAlert.activityIndicatorAlert!.addActivityIndicator()
        var topController:UIViewController = UIApplication.shared.keyWindow!.rootViewController!
        while ((topController.presentedViewController) != nil) {
            topController = topController.presentedViewController!
        }

        activityAlert.activityIndicatorAlert!.addAction(UIAlertAction.init(title:NSLocalizedString("Cancel", comment: ""), style: .default, handler: { (UIAlertAction) in
                self.dismissIPActivityAlert()
                onCancel?()
        }))
        topController.present(activityAlert.activityIndicatorAlert!, animated:true, completion:nil)
    }

    func dismissIPActivityAlert() {
        activityAlert.activityIndicatorAlert!.dismissActivityIndicator()
        activityAlert.activityIndicatorAlert = nil
    }
}

- Pak Ho Cheung

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这个答案非常完美！ - Mike Koene

Answer 3

对于使用Objective-C的人来说，我的解决方案是用一个更大的视图包装UIActivityIndicatorView，这样UIAlertView边缘的边距就不会太小了。

#import "UIAlertView+ActivityIndicator.h"

@implementation UIAlertView (ActivityIndicator)

+ (UIAlertView *)alertViewWithActivityIndicator:(NSString *)title delegate:(id<UIAlertViewDelegate>)delegate;
{
    UIAlertView *a = [[UIAlertView alloc] initWithTitle:title
                                                message:nil
                                               delegate:delegate
                                      cancelButtonTitle:nil
                                      otherButtonTitles:nil];

    UIView *v = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 50, 50)];
    UIActivityIndicatorView *aiv = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
    aiv.translatesAutoresizingMaskIntoConstraints = NO;
    [v addSubview:aiv];
    [v addConstraint:[NSLayoutConstraint constraintWithItem:aiv
                                                  attribute:NSLayoutAttributeCenterX
                                                  relatedBy:NSLayoutRelationEqual
                                                     toItem:v
                                                  attribute:NSLayoutAttributeCenterX
                                                 multiplier:1.0
                                                   constant:0]];
    [v addConstraint:[NSLayoutConstraint constraintWithItem:aiv
                                                  attribute:NSLayoutAttributeCenterY
                                                  relatedBy:NSLayoutRelationEqual
                                                     toItem:v
                                                  attribute:NSLayoutAttributeCenterY
                                                 multiplier:1.0
                                                   constant:0]];
    [aiv startAnimating];
    [a setValue:v forKey:@"accessoryView"];

    return a;
}

@end

- user89862

Answer 4

在Swift 3中被接受的答案：

var alert: UIAlertView = UIAlertView(title: "Title", message: "Please wait...", delegate: nil, cancelButtonTitle: "Cancel");


    let loadingIndicator = UIActivityIndicatorView(frame: CGRect(x:50, y:10, width:37, height:37))
    loadingIndicator.center = self.view.center;
    loadingIndicator.hidesWhenStopped = true
    loadingIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.gray
    loadingIndicator.startAnimating();

    alert.setValue(loadingIndicator, forKey: "accessoryView")
    loadingIndicator.startAnimating()

    alert.show();

- Jochen Österreicher

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UIAlertView在iOS 9.0中已被弃用。 - cmii