我正在使用新的 UIAlertController 来显示警报。我有这个代码:
// nil titles break alert interface on iOS 8.0, so we'll be using empty strings
UIAlertController *alert = [UIAlertController alertControllerWithTitle: title == nil ? @"": title message: message preferredStyle: UIAlertControllerStyleAlert];
UIAlertAction *defaultAction = [UIAlertAction actionWithTitle: cancelButtonTitle style: UIAlertActionStyleCancel handler: nil];
[alert addAction: defaultAction];
UIViewController *rootViewController = [UIApplication sharedApplication].keyWindow.rootViewController;
[rootViewController presentViewController:alert animated:YES completion:nil];
现在我想更改标题和消息字体、颜色、大小等。最好的方法是什么?
编辑: 我应该插入整个代码。我为 UIView 创建了类别,我可以为 iOS 版本显示正确的警报。
@implementation UIView (AlertCompatibility)
+( void )showSimpleAlertWithTitle:( NSString * )title
message:( NSString * )message
cancelButtonTitle:( NSString * )cancelButtonTitle
{
float iOSVersion = [[UIDevice currentDevice].systemVersion floatValue];
if (iOSVersion < 8.0f)
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle: title
message: message
delegate: nil
cancelButtonTitle: cancelButtonTitle
otherButtonTitles: nil];
[alert show];
}
else
{
// nil titles break alert interface on iOS 8.0, so we'll be using empty strings
UIAlertController *alert = [UIAlertController alertControllerWithTitle: title == nil ? @"": title
message: message
preferredStyle: UIAlertControllerStyleAlert];
UIAlertAction *defaultAction = [UIAlertAction actionWithTitle: cancelButtonTitle
style: UIAlertActionStyleCancel
handler: nil];
[alert addAction: defaultAction];
UIViewController *rootViewController = [UIApplication sharedApplication].keyWindow.rootViewController;
[rootViewController presentViewController:alert animated:YES completion:nil];
}
}
最佳答案
不确定这是否违反私有(private) API/属性,但在 ios8 上使用 KVC 对我有用
UIAlertController *alertVC = [UIAlertController alertControllerWithTitle:@"Dont care what goes here, since we're about to change below" message:@"" preferredStyle:UIAlertControllerStyleActionSheet];
NSMutableAttributedString *hogan = [[NSMutableAttributedString alloc] initWithString:@"Presenting the great... Hulk Hogan!"];
[hogan addAttribute:NSFontAttributeName
value:[UIFont systemFontOfSize:50.0]
range:NSMakeRange(24, 11)];
[alertVC setValue:hogan forKey:@"attributedTitle"];
UIAlertAction *button = [UIAlertAction actionWithTitle:@"Label text"
style:UIAlertActionStyleDefault
handler:^(UIAlertAction *action){
//add code to make something happen once tapped
}];
UIImage *accessoryImage = [UIImage imageNamed:@"someImage"];
[button setValue:accessoryImage forKey:@"image"];
郑重声明,使用这些私有(private) API 也可以更改警报操作的字体。同样,它可能会让您的应用程序被拒绝,我还没有尝试提交此类代码。
let alert = UIAlertController(title: nil, message: nil, preferredStyle: .ActionSheet)
let action = UIAlertAction(title: "Some title", style: .Default, handler: nil)
let attributedText = NSMutableAttributedString(string: "Some title")
let range = NSRange(location: 0, length: attributedText.length)
attributedText.addAttribute(NSKernAttributeName, value: 1.5, range: range)
attributedText.addAttribute(NSFontAttributeName, value: UIFont(name: "ProximaNova-Semibold", size: 20.0)!, range: range)
alert.addAction(action)
presentViewController(alert, animated: true, completion: nil)
// this has to be set after presenting the alert, otherwise the internal property __representer is nil
guard let label = action.valueForKey("__representer")?.valueForKey("label") as? UILabel else { return }
label.attributedText = attributedText
对于 XCode 10 及更高版本中的 Swift 4.2,最后 2 行现在是:
guard let label = (action!.value(forKey: "__representer")as? NSObject)?.value(forKey: "label") as? UILabel else { return }
label.attributedText = attributedText
关于ios - UIAlertController 自定义字体、大小、颜色,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/52114441/