iOS OC AlertViewController messa

//提示更新    更新类型：1-强制更新 2-提醒更新 3-可忽略更新
                    NSString *version_name = [NSString stringWithFormat:@"%@ %@", @"发现最新版本, 请下载", [data valueForKey:@"updateDescription"]];
//                    NSString *version_name = [NSString stringWithFormat:@"%@", @"发现最新版本, 请下载"];
                    UIAlertController *alertVC = [UIAlertController alertControllerWithTitle:@"检查更新" message:version_name preferredStyle:(UIAlertControllerStyleAlert)];
                    // Create a mutable paragraph style
                    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
                    paragraphStyle.alignment = NSTextAlignmentLeft;

                    // Create an attributed string with the message text and the paragraph style
                    NSString *messageText = version_name;
                    NSDictionary *attributes = @{
                        NSParagraphStyleAttributeName: paragraphStyle,
                        NSFontAttributeName: [UIFont systemFontOfSize:13.0] // Customize the font size if needed
                    };

                    NSAttributedString *attributedMessage = [[NSAttributedString alloc] initWithString:messageText attributes:attributes];

                    // Set the attributed message to the alert controller
                    [alertVC setValue:attributedMessage forKey:@"attributedMessage"];
                    
                    UIAlertAction *right = [UIAlertAction actionWithTitle:@"去更新" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
                        NSLog(@"点击更新了");
                        NSString *safari_url = [data valueForKey:@"url"];
                        if (safari_url.length > 0) {
                            dispatch_async(dispatch_get_main_queue(), ^{
                                if ([[UIApplication sharedApplication] canOpenURL:[NSURL URLWithString:safari_url]]) {
                                    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:safari_url] options:@{} completionHandler:^(BOOL success) {
                                        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
                                            exit(0);
                                        });
                                    }];
                                }
                            });
                        }
                    }];
                    
                    UIAlertAction *left = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
                        NSLog(@"取消");
                    }];
                    [alertVC addAction:right];
                    [alertVC addAction:left];
                    [[UIApplication sharedApplication].keyWindow.rootViewController presentViewController:alertVC animated:YES completion:^{
                        
                    }];
                }

解释
创建 UIAlertController:

objective
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UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Title" message:nil preferredStyle:UIAlertControllerStyleAlert];
创建一个 UIAlertController 实例，指定标题、消息为空（因为我们会使用富文本消息），以及警告样式。

创建段落样式并设置左对齐:

objective
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NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.alignment = NSTextAlignmentLeft;
创建一个 NSMutableParagraphStyle 实例，并将文本对齐方式设置为左对齐。

创建富文本消息:

objective
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NSString *messageText = @"This is a sample message that should be left aligned.";
NSDictionary *attributes = @{
NSParagraphStyleAttributeName: paragraphStyle,
NSFontAttributeName: [UIFont systemFontOfSize:13.0] // Customize the font size if needed
};
NSAttributedString *attributedMessage = [[NSAttributedString alloc] initWithString:messageText attributes:attributes];
创建一个包含消息文本的 NSAttributedString，并应用段落样式和其他属性（如字体大小）。

将富文本消息设置到 UIAlertController:

objective
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[alertController setValue:attributedMessage forKey:@"attributedMessage"];
使用 KVC (Key-Value Coding) 将富文本消息设置为 UIAlertController 的 attributedMessage 属性。

添加操作并显示警告控制器:

objective
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UIAlertAction *okAction = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:nil];
[alertController addAction:okAction];
[self presentViewController:alertController animated:YES completion:nil];
添加一个默认样式的“OK”操作，并显示警告控制器。