如何命名代码块并以不同的方法调用它？ [英] How to name a block of code and call it in a different method?

问题描述

我使用Grand Central Dispatch方法在队列中执行我的应用程序。我在该队列的计算中决定按钮的帧。我希望我的应用程序重新绘制其scren并在旋转后计算新帧。以下是我做的一些伪代码解释：

I use Grand Central Dispatch methods to do some executions of my app in a queue. I decide the frames for buttons in a calculation on that queue. I want my app to re-draw its scren and calculate new frames after rotation. Here is some pseudo code explanation from what i do:

 CGFloat a=123, b=24;
     dispatch_async(drawingQue, ^{
        //needed loops to get the total button count-how many ones will be drawn et..
        for(int x=0;x<someCount<x++){
           for(int y=0;y<anotherCount;y++){

        //needed frame&name ect assingments

        button.frame= CGRectMake(x+y, x-y, a, b);
        [button setTitle:@"abc"];}}
        };

这里我想要的是，如何给这个块命名并在

Here what i want is, how can i give this block a name and re-use it in the

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
} 

委托方法？例如，如果轮换是横向的，我想使用 a = 234 而不是123 ..请帮助。请提前感谢..

delegate method? For instance, if the rotation is landscape, i want to use a=234 instead of 123.. Any help please. Thanks in advance..

推荐答案

声明块类型的实例变量并使用 Block_copy 保持阻止：

Declare an instance variable of block type and use Block_copy to keep the block:

@interface My {
    void (^myBlock)(void);
}
@end

myBlock = Block_copy(^{
    ...block code...
});

// later call it
myBlock();

// don't forget to release it in dealloc

它是在将块存储在其文字范围之外<（ ^ {...} ）之前复制这一点非常重要，因为存储了原始块在堆栈上，当范围退出时将会死亡。

It is important to copy the block before storing it outside of the scope of its literal (^{...}), because the original block is stored on stack and will die when the scope exits.

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