随机选择的对象 -

Question

一个项目我已经改变我的背景颜色，三种颜色之一以下方法：

- (void) setBackgroundOfView { 
    // change the background color 
    UIColor *feijoa = [UIColor colorWithRed:0.565 green:0.82 blue:0.478 alpha:1]; /*#90d17a*/ 
    UIColor *turquoise = [UIColor colorWithRed:0.2 green:0.78 blue:0.773 alpha:1]; /*#33c7c5*/ 
    UIColor *lavendar = [UIColor colorWithRed:0.765 green:0.541 blue:0.898 alpha:1] /*#c38ae5*/ 
    UIColor *randomColor = random.choose(feijoa, turquoise, lavendar) // in pseudocode 
} 

是什么正确的方式做random.choose(feijoa, turquoise, lavendar)？

Answer 1

您可以将颜色存储到NSArray，并选择其中一个随机：

#include <stdlib.h> 

- (void) setBackgroundOfView { 
    // change the background color 
    UIColor *feijoa = [UIColor colorWithRed:0.565 green:0.82 blue:0.478 alpha:1]; /*#90d17a*/ 
    UIColor *turquoise = [UIColor colorWithRed:0.2 green:0.78 blue:0.773 alpha:1]; /*#33c7c5*/ 
    UIColor *lavendar = [UIColor colorWithRed:0.765 green:0.541 blue:0.898 alpha:1] /*#c38ae5*/ 

    NSArray *colors = @[feijoa, turquoise, lavendar]; 
    int index = arc4random_uniform(colors.count); 
    UIColor *randomColor = colors[index]; 
} 

Answer 2

我会成立三个数组。红，绿，蓝各一个。然后使用一个随机数发生器来选择一个索引。然后，你插入arrayRed [指数），arrayGreen [索引]，数组[蓝] arrayBlue [索引]

UIColor *feijoa = [UIColor colorWithRed:arrayRed[index) green:arrayGreen[Index] blue:arrayBlue[Index] alpha:1]; 

UE中的arc4Random()函数生成索引。这种方法现在允许您轻松地向阵列或其他颜色添加更多颜色。

Answer 3

你有一组结果：

UIColor *feijoa = [UIColor colorWithRed:0.565 green:0.82 blue:0.478 alpha:1]; /*#90d17a*/ 
    UIColor *turquoise = [UIColor colorWithRed:0.2 green:0.78 blue:0.773 alpha:1]; /*#33c7c5*/ 
    UIColor *lavendar = [UIColor colorWithRed:0.765 green:0.541 blue:0.898 alpha:1] /*#c38ae5*/ 

而且你需要选择一个随机。把结果到一个数组：

NSArray *choices = @[feijoa, turquoise, lavender]; 

然后选择一个随机指数：

int index = arc4random() % ([choices count]); 

所以，选择[指数]是你的项目