CGContext ----生成图片--image
//获取图片
+ (UIImage*) getImageWithColor:(UIColor*)color andHeight:(CGFloat)height
{
CGRect r= CGRectMake(0.0f, 0.0f, 1.0f, height);
UIGraphicsBeginImageContext(r.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, [color CGColor]);
CGContextFillRect(context, r);
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}