提示框：UIAlertView、UIAlertController以及UIAlertAction

//判断Xcode的版本

float version = [UIDevice currentDevice].systemVersion.floatValues;

if (version < 8.0) {

        //iOS8.0以前UIAlertView

        UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"提示" message:@"密码不正确，请重新输入。" delegate:self cancelButtonTitle:@"取消" otherButtonTitles:@"确定",@"很确定",@"非常确定", nil];

        //弹出alertView

        [alertView show];

    }else{

        //iOS8.0以后UIAlertController

        //UIAlertControllerStyleActionSheet上弹提示框

        //UIAlertControllerStyleAlert屏幕中间弹出提示框

        //使用模态展示

        UIAlertController *alertC = [UIAlertController alertControllerWithTitle:@"提示" message:@"密码错误，请重新输入。" preferredStyle:UIAlertControllerStyleActionSheet];

        //添加点击按钮

        [alertC addAction:[UIAlertAction actionWithTitle:@"确定" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {

            NSLog(@"点击确定");

        }]];

        [self presentViewController:alertC animated:YES completion:^{

        }];

}

#pragma mark - UIAlertViewDelegate的代理方法

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex{
    NSLog(@"%ld",buttonIndex);
}