iOS小Demo之字符串转图片

- (UIImage *)imageWithString:(NSString *)string font:(UIFont *)font width:(CGFloat)width height:(CGFloat)height textAlignment:(NSTextAlignment)textAlignment

{

    CGSize size = CGSizeMake(width, height);

    UIGraphicsBeginImageContext(size);

    CGContextRef context = UIGraphicsGetCurrentContext();

    [[UIColor whiteColor] set];

    CGRect rect = CGRectMake(0, 0, size.width ,  size.height);

    CGContextFillRect(context, rect);

    NSMutableParagraphStyle *paragraph = [[NSMutableParagraphStyle alloc] init];

    paragraph.alignment = textAlignment;

    NSShadow *shadow = [[NSShadow alloc]init];

    shadow.shadowBlurRadius = 0;//设置模糊度

    shadow.shadowColor = [UIColor whiteColor];//设置阴影颜色

    shadow.shadowOffset = CGSizeMake(1, 1);//设置阴影的偏移量

    

    NSDictionary *attributes = @ {

    NSForegroundColorAttributeName:[UIColor blackColor],

    NSFontAttributeName:font,

    NSShadowAttributeName:shadow,

    NSParagraphStyleAttributeName:paragraph

    };

    [string drawInRect:rect withAttributes:attributes];

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return image;

}