在快速枚举中跟踪索引 [英] Keep track of index in fast enumeration

问题描述

我想在使用快速枚举时获取当前对象的索引，即

I want to get the index of the current object when using fast enumeration, i.e.

for (MyClass *entry in savedArray) {
// What is the index of |entry| in |savedArray|?
}

推荐答案

a href =http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSArray_Class/NSArray.html> NSArray ，您将看到方法

Look at the API for NSArray and you will see the method

- (void)enumerateObjectsUsingBlock:(void (^)(id obj, NSUInteger idx, BOOL *stop))block

所以一试一试

[savedArray enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {

    //... Do your usual stuff here

    obj  // This is the current object
    idx  // This is the index of the current object
    stop // Set this to true if you want to stop

}];

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