集合<__NSArrayM:0x76c11b0>在枚举时发生了突变 [英] Collection <__NSArrayM: 0x76c11b0> was mutated while being enumerated

问题描述

我对 obj-c 比较陌生，所以我一定遗漏了一些东西，但是当敌人与墙壁相撞时，我的程序崩溃了.我已经找到了从循环中移除敌人的位置，虽然在循环中，但是对于我的生活，我无法弄清楚如何修复它.我的代码如下:

I'm relatively new to obj-c, so I must be missing something, but my program crash when an enemy collides with a wall. I've located where I'm removing the enemy from the loop, while in the loop, but for the life of me, i can't figure out how to fix it. My code is as follows:

(错误是[allEnemies removeObject:enemyType1];")

(the error is "[allEnemies removeObject:enemyType1];")

//一直在运行-(无效)更新:(ccTime)dt{

//ALWAYS RUNNING -(void) update:(ccTime)dt {

for (CCSprite *enemyType1 in allEnemies) { //for every attacking unit in allEnemies

    //Adjust the collison box for each enemey depending on the height of the enemy
    float a;
    float b;
    float yOne = (wall.contentSize.height-enemyType1.position.y);
    float yTwo = (wall.contentSize.height);
    float xTwo = 30;
    a = (xTwo*(yOne/yTwo)); // always < 1
    b = xTwo-a;             // always > 1


    //Create the altered collison box 
    CGRect enemyType1Rect = CGRectMake (
                enemyType1.position.x - (enemyType1.contentSize.width/2), 
                enemyType1.position.y - (enemyType1.contentSize.height/2), 
                enemyType1.contentSize.width+b, 
                enemyType1.contentSize.height
                                       );


    //If the enemey hits the wall, stop it, then add it to the attacking enemies array
    if (CGRectIntersectsRect(enemyType1Rect, wall.boundingBox)) {
        [enemyType1 stopAllActions];
        [allEnemies removeObject:enemyType1];
        [attackingEnemies addObject:enemyType1];            
    }


}
//Wall Collison END

推荐答案

好吧，正如错误所述，您在枚举数组时对其进行了变异.最简单的解决方法是 for (CCSprite *enemyType1 in [[allEnemies copy] autorelease]) 这样你就可以枚举数组的副本(这不会复制元素，只是给你另一个枚举它们的容器)，并且仍然可以修改可变数组.

Well, just as the error states, you mutated the array while it was being enumerated. The easiest fix is to do for (CCSprite *enemyType1 in [[allEnemies copy] autorelease]) This way you're enumerating a copy of the array (this does NOT copy the elements, just gives you another container to enumerate them in), and can still modify the mutable array.

枚举时不能修改容器.

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