Question

我想为选定的单元格和背景单元格生成相同的随机颜色。我用流动的代码成功实现了它。但有了这个我正确得到cell.background颜色，但我想在所选单元格的每个索引路径上设置浅色。那么，我该怎么办呢？假设，

if (indexpath.row ==1) {
    // lightcolor       
}
if (indexpath.row == 2) {
    // More light color as compare to indexpath.row ==1
}

@interface DisplayViewController () {
    DisplayCollectionViewCell *cell;
    float randomRed,randomGreen,randomBlue;
}

- (void)viewDidLoad {    
    randomRed = arc4random() % 255;
    randomGreen = arc4random() % 255;
    randomBlue = arc4random() % 255;
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"DisplayCellIphone" forIndexPath:indexPath];

    if (indexPath.row == _setRandomIndex) {
        // For Selected Color
        cell.layer.backgroundColor  =  [UIColor colorWithRed:randomRed * 0.9 /255.0 green:randomGreen * 0.9 /255.0 blue:randomBlue * 0.9/255.0 alpha:1].CGColor;
    } else {
       cell.backgroundColor = [UIColor colorWithRed:randomRed/255.0 green:randomGreen/255.0 blue:randomBlue/255.0 alpha:1.0];
    }
}

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {

    _count ++;
    randomRed = arc4random() % 255;
    randomGreen = arc4random() % 255;
    randomBlue = arc4random() % 255;

    if (indexPath.row == _setRandomIndex) {
        if (_count == 0) {
            [self addData:4];
        }      
        NSLog(@"Selected Right Cell");

        if (_count == 1 || _count == 2) {
            _setRandomIndex = arc4random() % 6;
            [self addData:6];            
           // _setRandomIndex = 2;          
        }
    // next cell till 20;
   }

Answer 1

您可以使用[UIColor colorWithHue: saturation: brightness: alpha:]

并更改亮度和饱和度值。设置参数的随机值，并使用此文章中的答案获取UIColor的组件，并通过仅更改亮度和饱和度值来保持色调值不变来生成颜色

Is there function to convert UIColor to Hue Saturation Brightness?

Answer 2

首先保留UIColor属性（我将其命名为cellColor）并使用下面的代码

if (indexpath.row ==1) {
    CGFloat hue = ( arc4random() % 256 / 256.0 );  //  0.0 to 1.0
    CGFloat saturation = ( arc4random() % 128 / 256.0 ) + 0.5;  //  0.5 to 1.0, away from white
    CGFloat brightness = ( arc4random() % 128 / 256.0 ) + 0.5;  //  0.5 to 1.0, away from black
    self.cellColor = [UIColor colorWithHue:hue saturation:saturation brightness:brightness alpha:1];    
}
if (indexpath.row == 2) {
    CGFloat hue, saturation, brightness, alpha;
    BOOL success = [self.cellColor getHue:&hue saturation:&saturation brightness:&brightness alpha:&alpha];
    self.cellColor = [self.cellColor initWithHue:hue saturation:saturation/2 brightness:brightness alpha:alpha;
}

现在，在indexPath 1条件下，您可以创建随机颜色。在indexPath 2条件下，我得到了色调和饱和度值，并将随机颜色的饱和度值更改为更亮。我希望这可以帮到你。

如何在UICollectionViewCell中设置暗色和浅色随机颜色？

2 个答案: