iOS颜色转换成图片的方法

//  颜色转换为背景图片
- (UIImage *)imageWithColor:(UIColor *)color {
    CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);
    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    
    CGContextSetFillColorWithColor(context, [color CGColor]);
    CGContextFillRect(context, rect);
    
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    return image;
}

使用例子

- (void)viewDidLoad {
    [super viewDidLoad];
    
    UIButton *button1 = [[UIButton alloc] initWithFrame:CGRectMake(50, 200, 100, 50)];
    [button1 setTitle:@"button1" forState:UIControlStateNormal];
    button1.backgroundColor = [UIColor orangeColor];
    [button1 addTarget:self action:@selector(button1BackGroundHighlighted:) forControlEvents:UIControlEventTouchDown];
    [button1 addTarget:self action:@selector(button1BackGroundNormal:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button1];
    
    UIButton *button2 = [[UIButton alloc] initWithFrame:CGRectMake(170, 200, 100, 50)];
    [button2 setTitle:@"button2" forState:UIControlStateNormal];
    [button2 setBackgroundImage:[self imageWithColor:[UIColor redColor]] forState:UIControlStateNormal];
    [button2 setBackgroundImage:[self imageWithColor:[UIColor grayColor]] forState:UIControlStateHighlighted];
    [self.view addSubview:button2];
}

效果如下图：