在objective-c中执行功能之前将图像设置为清除

Question

我正在开发一款应用。

我在UIViewController中有一个UIView。在UIIView中有16个UIImageView并将标记1设置为16。 并用于通过编码显示图像：

- (void)viewDidLoad {
    [super viewDidLoad];

    //some images are stored in array....
    [self selectnext];
}

-(void)selectnext{

    images=[[NSMutableArray alloc]initWithObjects:[UIImage imageNamed:@"Navarre-Family-Eye-Care-Navarre-Florida-Optometrist-Santa-Christmas-Toy-Safety.jpg"],[UIImage imageNamed:@"Christmas-Wallpapers-HD-Picture.jpg"],[UIImage imageNamed:@"Christmas-Wallpaper-jesus-9413550-1024-768.jpg"],[UIImage imageNamed:@"tree.jpg"],[UIImage imageNamed:@"luxury-christmas-napkins-father-christmas-1635-p.jpg"],[UIImage imageNamed:@"Navarre-Family-Eye-Care-Navarre-Florida-Optometrist-Santa-Christmas-Toy-Safety.jpg"],[UIImage imageNamed:@"Christmas-Wallpapers-HD-Picture.jpg"],[UIImage imageNamed:@"Christmas-Wallpaper-jesus-9413550-1024-768.jpg"],[UIImage imageNamed:@"tree.jpg"],[UIImage imageNamed:@"luxury-christmas-napkins-father-christmas-1635-p.jpg"], nil];

    NSString *dd=[NSString stringWithFormat:@"%@", images];
    NSLog(@"%@",dd);




    //used random number for image...and got a random image

    randomIndex1=arc4random() % images.count;



    selectedImage = [images objectAtIndex:randomIndex1]; //random selected image

    NSLog(@"%@",selectedImage);





    //stored 1 to 10 numbers in array...
    number = [[NSMutableArray alloc]initWithObjects:@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@"10", nil];

    //used random numbers in numbers...and got a random number....
    randomNumber = arc4random() % number.count; //random selected number

    num= [number objectAtIndex:randomNumber];

    ss=[NSString stringWithFormat:@"%@",num];

    NSLog(@"%@",ss);

    b = [ss integerValue];

    //NSLog(@"%ld",(long)b);





    //dispalying the image based on random number
    //  for (int i = 0; i <b; i++)
    // {
    // NSLog(@"%@", selectedImage);

    // _img.image = selectedImage;

    //cell.img.image=selectedImage;

    //}


    //used tag on UIImageView to display the image....

    for (int j = 1 ; j <=b ; j++){
      subView = [self.view viewWithTag:j];

        if ([subView isKindOfClass:[UIImageView class]]){
            ((UIImageView *)subView).image = selectedImage;



        }
    }

}

-(void)check{

    if (d==b) {



        selectedImage=[UIImage imageNamed:@""];

      //selectedImage.image=NULL;

        [self selectnext];


    }
    else
    {
        UIAlertController * alert=[UIAlertController alertControllerWithTitle:@"Title"
                                                                      message:@"Message"
                                                               preferredStyle:UIAlertControllerStyleAlert];

        UIAlertAction* Retry = [UIAlertAction actionWithTitle:@" please retry ..."
                                                            style:UIAlertActionStyleDefault
                                                          handler:^(UIAlertAction * action)
        {
            /** What we write here???????? **/
            NSLog(@"you pressed Yes, please button");

            // call method whatever u need
        }];

              [alert addAction:Retry];
               [self presentViewController:alert animated:YES completion:nil];    }
}

-(IBAction)button11:(id)sender
{
    d=1;
    [self check];
}
-(IBAction)button12:(id)sender
{
    d=2;
    [self check];
}
-(IBAction)button13:(id)sender
{
    d=3;
    [self check];
}
-(IBAction)button14:(id)sender
{
     d=4;
    [self check];
}
-(IBAction)button15:(id)sender
{
     d=5;
    [self check];
}
-(IBAction)button16:(id)sender
{
    d=6;
    [self check];
}
-(IBAction)button17:(id)sender
{
    d=7;
    [self check];
}
-(IBAction)button18:(id)sender
{
    d=8;
    [self check];
}
-(IBAction)button19:(id)sender
{
    d=9;
    *[self check];
}
-(IBAction)button20:(id)sender
{
    d=10;
    [self check];
}
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

但是当输出正确时它转到b == d然后在代码中调用名为selectcheck的函数。但在此之前我需要从imageview清除图像，否则输出如下面的屏幕截图。

那么，如何清除图像。

Answer 1

点击按钮，点击使用[self.view viewWithTag:yourImageviewTag]访问特定的UIImageview，然后从UIImageview中删除该图片。