UIAlertController 取代了 UIAlertView 和 UIActionSheet

屏幕快照 2018-03-21 17.20.20.png

声明：

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"标题" message:@"这个是UIAlertController的标题" preferredStyle:UIAlertControllerStyleAlert];
/*
typedef NS_ENUM(NSInteger, UIAlertControllerStyle) {
    UIAlertControllerStyleActionSheet = 0,
    UIAlertControllerStyleAlert
}
*/

添加项目：

    UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:nil];
    UIAlertAction *okAction = [UIAlertAction actionWithTitle:@"确定" style:UIAlertActionStyleDefault handler:nil];
    UIAlertAction *resetAction = [UIAlertAction actionWithTitle:@"重置" style:UIAlertActionStyleDestructive handler:nil];

/*
typedef NS_ENUM(NSInteger, UIAlertActionStyle) {
    UIAlertActionStyleDefault = 0,
    UIAlertActionStyleCancel,
    UIAlertActionStyleDestructive
}
*/
    [alertController addAction:cancelAction];
    [alertController addAction:okAction];
    [alertController addAction:resetAction];

//各个项目的顺序取决于类型，同类型的取决于添加顺序

展示：

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

含对话框的

165455_u3x5_1451688.png

    [alertController addTextFieldWithConfigurationHandler:^(UITextField *textField){
        textField.placeholder = @"登录";
        //添加监听
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(alertTextFieldDidChange:) name:UITextFieldTextDidChangeNotification object:textField];
    }];
    
    [alertController addTextFieldWithConfigurationHandler:^(UITextField *textField) {
        textField.placeholder = @"密码";
        textField.secureTextEntry = YES;
    }];

    UIAlertAction *okAction = [UIAlertAction actionWithTitle:@"确定" style:UIAlertActionStyleDefault handler:^(UIAlertAction *alertAction){
        //移除监听
        [[NSNotificationCenter defaultCenter] removeObserver:self name:UITextFieldTextDidChangeNotification object:nil];
    }];
    okAction.enabled = NO;//设置不可点击

监听方法

- (void)alertTextFieldDidChange:(NSNotification *)notification{
    UIAlertController *alertController = (UIAlertController *)self.presentedViewController;
    if (alertController) {
        UITextField *login = alertController.textFields.firstObject;
        UIAlertAction *okAction = alertController.actions.lastObject;
        okAction.enabled = login.text.length > 2;
    }
}

设置颜色

[cancelAction setValue:[UIColor orangeColor] forKey:@"_titleTextColor"];

170129_sZHK_1451688.png