实现一个将块用作回调的方法 [英] Implementing a method taking a block to use as callback

问题描述

我想写一个类似这样的方法:

I would like to write a method similar to this:

+(void)myMethodWithView:(UIView *)exampleView completion:(void (^)(BOOL finished))completion;

我基本上剥离了从 Apple 的 UIView 类方法之一中提取的语法:

I've basically stripped down the syntax taken from one of Apple's class methods for UIView:

+ (void)animateWithDuration:(NSTimeInterval)duration delay:(NSTimeInterval)delay options:(UIViewAnimationOptions)options animations:(void (^)(void))animations completion:(void (^)(BOOL finished))completion;

并希望它像这样使用:

[myFoo myMethodWithView:self.view completion:^(BOOL finished){
                     NSLog(@"call back success");
                 }];

我的问题是如何实现这一点?如果有人可以指出我的正确文档，那将是很棒的，并且非常基本的示例将不胜感激(或 Stack Overflow 上的类似答案——我找不到).我仍然不太了解委托，无法确定这是否是正确的方法！

My question is how can I implement this? If someone can point me to the correct documentation that would be great, and a very basic example would be much appreciated (or a similar answer on Stack Overflow -- I couldn't find one). I still don't quite know enough about delegates to determine whether that is even the correct approach!

我已经在实现文件中放了一个粗略的例子，说明我希望它在实现文件中的内容，但由于我找不到信息，所以只能猜测了.

I've put a rough example of what I would have expected it to be in the implementation file, but as I can't find info it's guess work.

+ (void)myMethod:(UIView *)exampleView completion:(void (^)(BOOL finished))completion {
    // do stuff

    if (completion) {
        // what sort of syntax goes here? If I've constructed this correctly!
    }

}

推荐答案

你可以像调用普通函数一样调用块:

You can call a block like a regular function:

BOOL finished = ...;
if (completion) {
    completion(finished);
}

这意味着使用您的示例实现一个完整的块功能将如下所示:

So that means implementing a complete block function using your example would look like this:

+ (void)myMethod:(UIView *)exampleView completion:(void (^)(BOOL finished))completion {
    if (completion) {
        completion(finished);
    }
}

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