Question

我有一个应用程序，你有3个按钮，如果按下按钮，三个按钮的按钮图像会改变，但是按钮2和按钮3可能与按钮1的按钮图像不同，按钮3可能没有相同的图像按钮2

我试过这个但是没有用

       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;

Answer 1

在这里你设置了self.picture1图像在else部分，所以如果第一个任何条件为真，那么self.picture1图像将不会设置，所以你面对的这个问题也为{{{}之外的每个按钮添加了setImage的代码1}}部分，下面的代码

else

Answer 2

试试这个......

 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;

Answer 3

试试这个：

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];

Answer 4

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];
    }

Answer 5

看起来其他副本已被关闭为重复。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一个随机索引有时会产生当前索引（它是随机的，所以这发生在1 / array.count概率）。这是一种排除给定指数的方法......

- (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，您可能会考虑使用不同的算法来排除一个索引

如何给每个按钮一个不同的图像？

5 个答案: