如何声明一个返回UIView的块？

Question

I keep trying to create a block that will return a UIView after it fetches it from the background. I got the fetch from the background part, but I am having trouble setting up the block. This code works, but I want a block that can be called from another file. Thanks in advance.

I can't call launchAd for viewDidLoad, and nothing works.

typedef void (^launchAd)(UIView *);
-(void)launchAd:(void (^)(UIView *ad))block
{

}

Answer 1

Probably you can try something like below:

//class file 1:     
+ (void) doYourStuff:(void (^)(UIView* returnedView))successBlock {
    successBlock(returnedView);
}

//class file 2: 
[class1 doYourStuff:success:^(UIView* returnedView) {
    //do whatever you want with the returned data
}];

If you want to add failure block to return failure scenarios:

+ (void) doYourStuff:(void (^)(UIView* returnedView))successBlock
           failure:(void (^)(NSError *error))failureBlock {
           if (getView)
            successBlock(returnedView);
           else 
            failureBlock(error);
}