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我有一个应用程序，您有 3 个按钮，如果您按下一个按钮，三个按钮的按钮图像会发生变化，但按钮 2 和按钮 3 的图片可能与按钮 1 的图片不同，而按钮 3 的图片可能与按钮 2 的图片不同

我已经尝试过了，但它没有用

       NSInteger imageIndex1 = arc4random_uniform(images.count);
       NSInteger imageIndex2 = arc4random_uniform(images.count);
       NSInteger imageIndex3 = arc4random_uniform(images.count);

    if (imageIndex1 == imageIndex2 ) {
        imageIndex2 = arc4random_uniform(images.count);
    }

    else if (imageIndex1 == imageIndex3  ) {
        imageIndex3 = arc4random_uniform(images.count);
    }

        else if (imageIndex2 == imageIndex3  ) {
            imageIndex3 = arc4random_uniform(images.count);

    }



    else
       [self.picture1 setImage:images[imageIndex1] forState:UIControlStateNormal];
       [self.picture2 setImage:images[imageIndex2] forState:UIControlStateNormal];
       [self.picture3 setImage:images[imageIndex3] forState:UIControlStateNormal];
      imageIndex1 = imageIndex2;
      imageIndex1 = imageIndex3;
      imageIndex2 = imageIndex3;
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5 回答 5

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看起来这个的另一个副本被关闭为重复。以下是该问题的答案：问题的目标是随机更改按钮上的图像。但问题是，在图像数组中选择随机索引有时会生成当前索引（它是随机的，因此发生这种情况的概率为 1/array.count）。这是一种排除给定索引的方法...

- (NSUInteger)randomUnsignedLessThan:(NSInteger)max excluding:(NSUInteger)exclude {

    NSInteger firstTry = -1;
    while (firstTry == exclude) firstTry = arc4random() % max;
    return firstTry;
}

请注意，此方法将始终调用 arc4random 一次，并且需要 1+N 次调用，概率为 1/max^N，因此对于低范围和高性能要求，您可能会考虑使用不同的算法来排除一个索引。

于 2012-12-20T15:51:50.777 回答
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尝试这个：

NSInteger imageIndex1 = arc4random_uniform(images.count);
NSInteger imageIndex2 = arc4random_uniform(images.count);
NSInteger imageIndex3 = arc4random_uniform(images.count);

while (imageIndex2 == imageIndex1 ) {
    imageIndex2 = arc4random_uniform(images.count);
}

while (imageIndex3 == imageIndex1 ) {
    imageIndex3 = arc4random_uniform(images.count);
}


[self.picture1 setImage:images[imageIndex1] forState:UIControlStateNormal];
[self.picture2 setImage:images[imageIndex2] forState:UIControlStateNormal];
[self.picture3 setImage:images[imageIndex3] forState:UIControlStateNormal];
于 2012-12-12T12:59:22.943 回答
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在这里，您将self.picture1图像设置在 else 部分，因此如果首先任何条件为真，则self.picture1不会设置图像，因此您面临的这个问题还为每个按钮添加 setImage 的代码else，如下代码

       [self.picture1 setImage:images[imageIndex1] forState:UIControlStateNormal];
       [self.picture2 setImage:images[imageIndex2] forState:UIControlStateNormal];
       [self.picture3 setImage:images[imageIndex3] forState:UIControlStateNormal];
于 2012-12-12T12:56:04.893 回答
0

尝试这个...

 if (imageIndex2 == imageIndex1 ) {
            imageIndex2 = arc4random_uniform(images.count);
    }

    if (imageIndex3 == imageIndex1 ) {
            imageIndex3 = arc4random_uniform(images.count);
          }


[self.picture1 setImage:images[imageIndex1] forState:UIControlStateNormal];
       [self.picture2 setImage:images[imageIndex2] forState:UIControlStateNormal];
       [self.picture3 setImage:images[imageIndex3] forState:UIControlStateNormal];
       imageIndex1 = imageIndex2;
       imageInde

x1 = imageIndex3;
于 2012-12-12T12:57:43.640 回答
0

我想我找到了解决方案。这是现在的代码：

    Boolean p1 =true;
    Boolean p2 = true;
    Boolean p3 = true;


       NSInteger imageIndex1 = arc4random_uniform(images.count);
       NSInteger imageIndex2 = arc4random_uniform(images.count);
       NSInteger imageIndex3 = arc4random_uniform(images.count);

    if (imageIndex1 == imageIndex2 ) {
        p1 = false;
        imageIndex2 = arc4random_uniform(images.count);

    }

    if(imageIndex1 == imageIndex3  ) {
        p2 = false;
        imageIndex1 = arc4random_uniform(images.count);

    }

       if (imageIndex2 == imageIndex3  ) {
           p3 = false;
            imageIndex3 = arc4random_uniform(images.count);


    }



    if(p1 == true && p2 == true && p3 == true) {
       [self.picture1 setImage:images[imageIndex1] forState:UIControlStateNormal];
       [self.picture2 setImage:images[imageIndex2] forState:UIControlStateNormal];
       [self.picture3 setImage:images[imageIndex3] forState:UIControlStateNormal];
    }
于 2012-12-12T14:36:26.460 回答