如何从Objective-C中的方法返回C数组？ [英] How to return a C-array from method in Objective-C?

问题描述

我有一个函数返回一个变量，我想知道如何返回一个数组的问题是它不是一个NSArray它只是一个平均C数组像这样...

- （b2Fixture *）addFixturesToBody：（b2Body *）body forShapeName：（NSString *）shape
{
BodyDef * so = [shapeObjects objectForKey：shape];
assert（so）;
FixtureDef * fix = so-> fixtures;
int count = -1;
b2Fixture * Fixi [4];
while（fix）
{

count ++;
NSLog（@count =％d，count）;
Fixi [count] = body-> CreateFixture（& fix-> fixture）;
if（Fixi [count]！= 0）{
NSLog（@Fixi％d is not 0，count）
}
if（body-> CreateFixture（& fix-> fixture）！= 0）{
NSLog（@body％d is not 0，count）
}

fix = fix-> next;

}

return * Fixi;

}


如果你看到一些变量类型，你不知道因为我使用cocos2d框架做一个游戏，但我返回一个b2Fixture的变量...这个代码编译但是只保存数组fixi [0]的第一个块的值不是像I

解决方案

您可以' t返回一个局部数组。你需要做一些动态分配，或者拉一个把数组放在结构中的技巧。

这里有一个链接，可帮助您深入了解。

I have a function that returns a variable and I want to know how to return an array the issue is it isn't an NSArray it is just an average C array like this...

-(b2Fixture*) addFixturesToBody:(b2Body*)body forShapeName:(NSString*)shape
{
    BodyDef *so = [shapeObjects objectForKey:shape];
    assert(so);
       FixtureDef *fix = so->fixtures;
    int count = -1;
    b2Fixture *Fixi[4];
    while(fix)
    {

        count++;
        NSLog(@"count = %d",count);
        Fixi[count]= body->CreateFixture(&fix->fixture);
        if (Fixi[count]!=0) {
            NSLog(@"Fixi %d is not 0",count);
        }
        if (body->CreateFixture(&fix->fixture)!=0) {
            NSLog(@"body %d is not 0",count);
        }

        fix = fix->next;

    }

    return *Fixi;

}

If you see some variable types you don't know it's because I'm using cocos2d framework to make a game but I'm returning a variable of b2Fixture... This code compiles however only saves the value of the first block of the array "fixi[0]" not the whole array like I want to pass

anyhelp :) thankyou

解决方案

You can't return a local array. You'll need to do some kind of dynamic allocation or pull a trick like having the array inside a structure.

Here is a link to an in-depth article that should help you out.

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