iOS：如何生成随机柔和的颜色？

2 回答

• 0

  John Coates的Swift实现出现在这里：https://gist.github.com/JohnCoates/725d6d3c5a07c4756dec但他错误地称之为"pastel"，尽管不包括所需的浅蓝色以实现该效果 .

  我的John-git的Objective-C版本（混合浅蓝色）在这里：

  // Adapted from Stack Overflow answer by David Crow http://stackoverflow.com/a/43235
  -(UIColor*) generateRandomPastelColor
  {
      // Randomly generate numbers
      CGFloat red  = ( (CGFloat)(arc4random() % 256) ) / 256;
      CGFloat green  = ( (CGFloat)(arc4random() % 256) ) / 256;
      CGFloat blue  = ( (CGFloat)(arc4random() % 256) ) / 256;
  
      // Mix with light-blue
      CGFloat mixRed = 1+0xad/256, mixGreen = 1+0xd8/256, mixBlue = 1+0xe6/256;
      red = (red + mixRed) / 3;
      green = (green + mixGreen) / 3;
      blue = (blue + mixBlue) / 3;
      return [UIColor colorWithRed:red green:green blue:blue alpha:1];
  }
  

  编辑

  我已经改进了算法，通过将白色混合到计算中来使颜色变得更亮（通过将浅蓝色加1并且跳过3而不是2） .

  这是上述方法的测试代码（您可以替换新项目的viewDidLoad并运行）：

  #define RECT_SIZE 30
  
  - (void)viewDidLoad {
      [super viewDidLoad];
      CGFloat screenWidth = [UIScreen mainScreen].bounds.size.width;
      CGFloat screenHeight = [UIScreen mainScreen].bounds.size.height;
      int horizontals = screenWidth / RECT_SIZE;
      int verticals = screenHeight / RECT_SIZE;
      float offset_h = ((int)screenWidth % RECT_SIZE)/2;
      float offset_v = ((int)screenHeight % RECT_SIZE)/2;
      for (int v=0; v < verticals; v++) {
          for (int h=0; h < horizontals; h++) {
              CGRect rect = CGRectMake(offset_h + h * RECT_SIZE, offset_v + v * RECT_SIZE, RECT_SIZE, RECT_SIZE);
              UIView *square = [[UIView alloc] initWithFrame:rect];
              square.backgroundColor = [self generateRandomPastelColor];
              [self.view addSubview:square];
          }
      }
  }
  

  回复于 2024-05-14T13:10:46+08:00
• 2

  我已使用此代码设置随机背景颜色 .

  UIColor *bgColor = color ? color : [self randomColor];
  
      - (UIColor *)randomColor {
  
          srand48(arc4random());
  
          float red = 0.0;
          while (red < 0.1 || red > 0.84) {
              red = drand48();
          }
  
          float green = 0.0;
          while (green < 0.1 || green > 0.84) {
              green = drand48();
          }
  
          float blue = 0.0;
          while (blue < 0.1 || blue > 0.84) {
              blue = drand48();
          }
  
          return [UIColor colorWithRed:red green:green blue:blue alpha:1.0f];
      }
  

  回复于 2024-05-14T13:10:46+08:00