iOS隨機顏色

iOS隨機顏色

#import @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    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將隨機產生的顏色繪製成圖片。-(void)createImage{    NSString* path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES) objectAtIndex:0];    path = @"/Users/shouqiangwei/Desktop/未命名檔案夾 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++) {        UIColor *color = [UIColorrandomColor];        [_currentColorImageViewsetBackgroundColor:color];        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);            //建立圖片上的數字。            [markNum drawAtPoint:markPoint withFont:[UIFont systemFontOfSize:fontSize]];            img = UIGraphicsGetImageFromCurrentImageContext();            self.imageView.image= img;            UIGraphicsEndImageContext();            //建立到本地。            imgData = [NSDatadataWithData:UIImageJPEGRepresentation(img,1.0f)];            [imgData writeToFile:imgURLoptions:NSDataWritingAtomicerror:&err];            if (err) {                NSLog(@"error: %@\nimage:%@", err.localizedDescription, imgName);            } else {                NSLog(@"done: %@", imgName);            }        }    }}