Question

我有22个图像... 11个（右墙1，右墙2，右墙3等），其他11个（左墙1，左墙2，左墙3等）

我通过将y值设置为前一个墙y值加上墙的高度（所有墙都是相同的高度）来将每个人放在另一个上面。

这很好用！

现在，我试图使用arc4random设置x值，这样它们就会在一定范围内跳到整个地方（对于左侧墙：（ - 35到15）＆amp;对于右侧墙：（330到405）））...

右侧墙壁工作得很好，但左侧墙壁，其中一些可以工作，但大多数都不会出现在屏幕上。

我手动将1的x值设置为-45，它显示在屏幕上，并且低于arc4random允许它去的位置。

我能想到的唯一问题是我的左墙减去了错误吗？

以下是设置墙壁位置的代码，我在整个项目中还没有其他代码。

-(void)awakeFromNib {

        rightWall1.center = CGPointMake( ((arc4random()%75)+330), (460-((rightWall1.frame.size.height)/2)) );//460 = bottom of screen
        rightWall2.center = CGPointMake( ((arc4random()%75)+330), ((rightWall1.center.y)-(rightWall2.frame.size.height)) );
        rightWall3.center = CGPointMake( ((arc4random()%75)+330), ((rightWall2.center.y)-(rightWall3.frame.size.height)) );
        rightWall4.center = CGPointMake( ((arc4random()%75)+330), ((rightWall3.center.y)-(rightWall4.frame.size.height)) );
        rightWall5.center = CGPointMake( ((arc4random()%75)+330), ((rightWall4.center.y)-(rightWall5.frame.size.height)) );
        rightWall6.center = CGPointMake( ((arc4random()%75)+330), ((rightWall5.center.y)-(rightWall6.frame.size.height)) );
        rightWall7.center = CGPointMake( ((arc4random()%75)+330), ((rightWall6.center.y)-(rightWall7.frame.size.height)) );
        rightWall8.center = CGPointMake( ((arc4random()%75)+330), ((rightWall7.center.y)-(rightWall8.frame.size.height)) );
        rightWall9.center = CGPointMake( ((arc4random()%75)+330), ((rightWall8.center.y)-(rightWall9.frame.size.height)) );
        rightWall10.center = CGPointMake( ((arc4random()%75)+330), ((rightWall9.center.y)-(rightWall10.frame.size.height)) );
        rightWall11.center = CGPointMake( ((arc4random()%75)+330), ((rightWall10.center.y)-(rightWall11.frame.size.height)) );


        leftWall1.center = CGPointMake( (15-(arc4random()%50)), (460-((leftWall1.frame.size.height)/2)) );
        leftWall2.center = CGPointMake( (15-(arc4random()%50)), ((leftWall1.center.y)-(leftWall2.frame.size.height)) );
        leftWall3.center = CGPointMake( (15-(arc4random()%50)), ((leftWall2.center.y)-(leftWall3.frame.size.height)) );
        leftWall4.center = CGPointMake( (15-(arc4random()%50)), ((leftWall3.center.y)-(leftWall4.frame.size.height)) );
        leftWall5.center = CGPointMake( (15-(arc4random()%50)), ((leftWall4.center.y)-(leftWall5.frame.size.height)) );
        leftWall6.center = CGPointMake( (15-(arc4random()%50)), ((leftWall5.center.y)-(leftWall6.frame.size.height)) );
        leftWall7.center = CGPointMake( (15-(arc4random()%50)), ((leftWall6.center.y)-(leftWall7.frame.size.height)) );
        leftWall8.center = CGPointMake( (15-(arc4random()%50)), ((leftWall7.center.y)-(leftWall8.frame.size.height)) );
        leftWall9.center = CGPointMake( (15-(arc4random()%50)), ((leftWall8.center.y)-(leftWall9.frame.size.height)) );
        leftWall10.center = CGPointMake( (15-(arc4random()%50)), ((leftWall9.center.y)-(leftWall10.frame.size.height)) );
        leftWall11.center = CGPointMake( (15-(arc4random()%50)), ((leftWall10.center.y)-(leftWall11.frame.size.height)) );

}

Answer 1

事实证明你无法使用arc4random获得负整数值（因为arc4random使用模数......整数...... ??哈哈）所以我使用了一个浮点数......

不能说：

(-1)*(arc4random() ....

你必须说：

float num1;
num1 = -1;
(num1)*(arc4random() ....

很奇怪......减去相同的......你必须在arc4random中添加一个负1浮点数。

随机CGPoint x值不起作用

1 个答案: