如何给每个按钮一个不同的图像？ [英] How give each button a different image?

问题描述

我有一个应用程序，你有3个按钮，如果你按一个按钮，三个按钮的按钮图像改变但按钮2和按钮3可能没有与按钮1相同的图像，按钮3可能没有相同的图片作为按钮2

I have a application where you have 3 buttons and if you press a button the button image of the three buttons change but button 2 and button 3 may not have the same picture as button 1 and button 3 may not have the same picture as button 2

我试过这个但是它不起作用

I have tried this but it didn't work

       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;

推荐答案

看起来其他副本已关闭为重复。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一个随机索引有时会生成当前索引（它是随机的，所以这发生在1 / array.count概率）。这是一种排除给定索引的方法...

Looks like the other copy of this was closed as duplicate. Here's the answer from that one: The goal of the question is to change images on buttons at random. But the problem is that picking a random index into an array of images sometimes generates the current index (it's random, so this happens with 1/array.count probability). Here's an approach that excludes a given index...

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

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

请注意，此方法始终会调用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，您可以考虑使用不同的算法来排除一个索引。

Note that this approach will always call arc4random once, and require 1+N calls with a probability of 1/max^N, so for low ranges, and high performance requirements, you might consider a different algorithm to exclude the one index.

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