iOS 自定义UIAlertController的字体、颜色、大小

先来说说系统的界面提醒吧。

一、系统UIAlertController

苹果自iOS8开始，就已经废弃了之前用于界面提醒的UIAlertView类以及UIActionSheet，取而代之的是UIAlertController以及UIAlertAction，从实际使用情况来看，苹果把之前不同类型/样式的通知实现方法进行了统一，简化了有关提醒功能的实现。

1.UIAlertController的使用

- 常用方法和属性

+ (instancetype)alertControllerWithTitle:(nullable NSString *)title message:(nullable NSString *)message preferredStyle:(UIAlertControllerStyle)preferredStyle; //初始化

- (void)addAction:(UIAlertAction *)action;//添加一个按钮选项

- (void)presentViewController:(UIViewController *)viewControllerToPresent animated: (BOOL)flag completion:(void (^ __nullable)(void))completion NS_AVAILABLE_IOS(5_0);//显示提醒

提醒的样式把弹出提醒和底部提醒进行了统一，使用preferredStyle来区分

typedef NS_ENUM(NSInteger, UIAlertControllerStyle) {

UIAlertControllerStyleActionSheet = 0,

UIAlertControllerStyleAlert

}

2.UIAlertAction的使用

UIAlertAction是定义提醒中每个按钮的样式以及用户点击后所执行的操作

+ (instancetype)actionWithTitle:(nullable NSString *)title style:(UIAlertActionStyle)style handler:(void (^ __nullable)(UIAlertAction *action))handler;

提醒按钮的样式是通过UIAlertActionStyle参数决定的

typedef NS_ENUM(NSInteger, UIAlertActionStyle) {

UIAlertActionStyleDefault = 0,

UIAlertActionStyleCancel,

UIAlertActionStyleDestructive

} NS_ENUM_AVAILABLE_IOS(8_0);

3.代码示例

UIAlertController* alert = [UIAlertControlleralertControllerWithTitle:@"提示"message:@"是否要重新开始？"preferredStyle:UIAlertControllerStyleAlert];

UIAlertAction* defaultAction = [UIAlertActionactionWithTitle:@"是"style:UIAlertActionStyleDefaulthandler:^(UIAlertAction* action) {self.timeLabel.text =@"5";}];

UIAlertAction* Action1 = [UIAlertActionactionWithTitle:@"取消"style:UIAlertActionStyleCancelhandler:^(UIAlertAction*action) {

}];

[alert addAction:defaultAction];

[alert addAction:Action1];

[selfpresentViewController:alert animated:YEScompletion:nil];

二、自定义UIAlertC0ntroller使用

使用KVC的方式改变UIAlertController的样式

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"标题" message:@"内容" preferredStyle:UIAlertControllerStyleAlert]; 

UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:nil];

//Add image 这里可以给button添加图片

UIImage *accessoryImage = [UIImage imageNamed:@"selectRDImag.png"];

accessoryImage = [accessoryImage imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];

[cancelAction setValue:accessoryImage forKey:@"image"];

//设置cancelAction的title颜色

[cancelAction setValue:[UIColor lightGrayColor] forKey:@"titleTextColor"];

//设置cancelAction的title的对齐方式

[cancelAction setValue:[NSNumber numberWithInteger:NSTextAlignmentLeft] forKey:@"titleTextAlignment"];

[alertController addAction:cancelAction];

UIAlertAction *okAction = [UIAlertAction actionWithTitle:@"确定" style:UIAlertActionStyleDefault handler:nil];

//设置okAction的title颜色

[okAction setValue:[UIColor greenColor] forKey:@"titleTextColor"];

[alertController addAction:okAction];

//Custom Title,使用富文本来改变title的字体大小

NSMutableAttributedString *hogan = [[NSMutableAttributedString alloc] initWithString:@"Presenting the Hulk Hogan!"];

[hogan addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:20] range:NSMakeRange(13, 11)];

[alertController setValue:hogan forKey:@"attributedTitle"];

NSMutableAttributedString *hogan1 = [[NSMutableAttributedString alloc] initWithString:@"hjasdghjdfsgkfdghfdgsgdsfgdsfg"];

[hogan1 addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:20] range:NSMakeRange(13, 11)];

[alertController setValue:hogan1 forKey:@"attributedMessage"];

[self presentViewController:alertController animated:YES completion:nil];

最终效果图