UIAlertController的使用

preferredStyle是个枚举类型

typedef NS_ENUM(NSInteger, UIAlertControllerStyle) {
    UIAlertControllerStyleActionSheet = 0,该状态是类似于(UIAlertView)
    UIAlertControllerStyleAlert  该状态是UIActionSheet(从底部弹出来的弹窗)
}

        UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"升级提示"message:@"温馨提示" preferredStyle:UIAlertControllerStyleActionSheet];
   
        [alert addAction:[UIAlertAction actionWithTitle:@"相机" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action)
                          {
                              NSLog(@"点击现在升级按钮");
                          }]];
        [alert addAction:[UIAlertAction actionWithTitle:@"相册" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action)
                          {
                              NSLog(@"点击下次再说按钮");
                          }]];
    
    [self presentViewController:alert animated:YES completion:nil];