AlertView in material design,support iOS 7 and above.
MDAlertView *alert = [[MDAlertView alloc]initWithTitle:<#(NSString *)#> message:<#(NSString *)#> image:<#(UIImage *)#> delegate:<#(id)#> cancelButtonTitle:<#(NSString *)#> confirmButtonTitle:<#(NSString *)#>];
alert.delegate = self;
[alert show];