在块中更改实例变量 [英] Changing an instance variable in a block

问题描述

我对于如何在块内更改实例变量感到非常困惑.

I am quite confused about how to change an instance variable inside of a block.

接口文件(.h):

@interface TPFavoritesViewController : UIViewController {
    bool refreshing;
}

实现:

__weak TPFavoritesViewController *temp_self = self;
refreshing = NO;
[myTableView addPullToRefreshWithActionHandler:^{
    refreshing = YES;
    [temp_self refresh];
}];

您可能会猜到，当我尝试更改该块内部的刷新ivar时，会收到一个保留周期警告.我该怎么做而不会出错?

As you might guess, I get a retain cycle warning when I try to change the refreshing ivar inside of the block. How would I do this without getting an error?

推荐答案

您对refreshing的赋值是对self的隐式引用，它的简写为:

Your assignment to refreshing is an implicit reference to self, it is shorthand for:

self->refreshing = YES;

因此出现循环警告.更改为:

hence the cycle warning. Change it to:

temp_self->refreshing = YES;

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