iOS 随机颜色（UIColor）

#import @interface UIColor (RandomColor) (UIColor *) randomColor; @end #import "UIColorRandomColor.h" @implementation UIColor (RandomColor) (UIColor *) randomColor { CGFloat hue = ( arc4random() % 256 / 256.0 ); //0.0 to 1.0 CGFloat satura

#import

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@interface UIColor (RandomColor) +(UIColor *) randomColor; @end #import "UIColor+RandomColor.h" @implementation UIColor (RandomColor) +(UIColor *) randomColor { 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 www.stuhack.com CGFloat brightness = ( arc4random() % 128 / 256.0 ) + 0.5; //0.5 to 1.0,away from black return [UIColor colorWithHue:hue saturation:saturation brightness:brightness alpha:1]; @end 将随机生成的颜色绘制成图片。 copyright www.stuhack.com -(void)createImage { copyright www.stuhack.com NSString* path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES) objectAtIndex:0]; path = @"/Users/shouqiangwei/Desktop/未命名文件夹 2"; NSLog(@"path = %@",path); NSString *imgName; NSString *imgURL; NSString *markNum; UIImage *img; NSData *imgData; NSError *err; int width= 1000, height=1000, fontSize; CGPoint markPoint; int baseLength = 320; NSFileManager *fm = [NSFileManagerdefaultManager]; for (int i=0; i<1000; i++) { www.stuhack.com UIColor *color = [UIColorrandomColor]; [_currentColorImageViewsetBackgroundColor:color]; www.stuhack.com imgName = [NSString stringWithFormat:@"%i.jpg", i+1]; _lblCount.text = imgName; imgURL = [path stringByAppendingPathComponent:imgName]; if (![fm fileExistsAtPath:imgURL]) { const CGFloat *colorComps = CGColorGetComponents(color.CGColor); markNum = [NSString stringWithFormat:@"%i", i+1]; fontSize = width / 5; markPoint = CGPointMake(fontSize/2, fontSize/2); UIGraphicsBeginImageContext(CGSizeMake(width, height)); CGContextRef ctx =UIGraphicsGetCurrentContext(); CGContextSetRGBFillColor(ctx, colorComps[0], colorComps[1], colorComps[2], colorComps[3]); CGContextFillRect(ctx, CGRectMake(0, 0, width, height)); CGContextSetRGBFillColor(ctx, 1.0, 1.0, 1.0,1.0); [markNum drawAtPoint:markPoint withFont:[UIFont systemFontOfSize:fontSize]]; img = UIGraphicsGetImageFromCurrentImageContext(); self.imageView.image= img; copyright www.stuhack.com UIGraphicsEndImageContext(); //创建到本地。 imgData = [NSDatadataWithData:UIImageJPEGRepresentation(img,1.0f)]; [imgData writeToFile:imgURLoptions:NSDataWritingAtomicerror:&err]; if (err) { NSLog(@"error: %@\nimage:%@", err.localizedDescription, imgName); } else { NSLog(@"done: %@", imgName); } } } }