Question

我创建了一个UIImageView，其中包含两个UILabel作为其子视图：

 UIImageView *img=[[UIImageView alloc]initWithFrame:CGRectMake(0, 0, 320, [[UIScreen mainScreen] bounds].size.height)];
    img.backgroundColor=self.view.backgroundColor;

    UILabel *textOne=[[UILabel alloc]initWithFrame:CGRectMake(10, 10, 290, 250)];
    textOne.text=_textOneLabel.text;
    textOne.textColor=_textOneLabel.textColor;

    UILabel *textTwo = [[UILabel alloc] initWithFrame:CGRectMake(100,180,200,100)];
    textTwo.text=_textTwoLabel.text;
    textTwo.textColor=_textTwoLabel.textColor;

    [img addSubview:textOne];
    [img addSubview:textTwo];

    UIImageWriteToSavedPhotosAlbum(img.image, nil, nil, nil); //img.image is null

我想创建一个UIImage，将其保存在相机胶卷中，UIImageView和2创建UILabel。 img.image返回null，因为没有为UIImageView分配图像。
你知道如何实现这个目标吗？

Answer 1

使用以下方法将UIImageView转换为UIImage。

UIImage *image = [self ChangeImageViewToImage:img];

//方法

-(UIImage *) ChangeImageViewToImage : (UIImageView *) view{

 UIGraphicsBeginImageContextWithOptions(view.bounds.size, view.opaque, 0.0);
 [view.layer renderInContext:UIGraphicsGetCurrentContext()];

 UIImage * img = UIGraphicsGetImageFromCurrentImageContext();

 UIGraphicsEndImageContext();

 return img;

}

Answer 2

这应该可以帮到你

/* Creates an image with a home-grown graphics context, burns the supplied string into it. */
- (UIImage *)burnTextIntoImage:(NSString *)text :(UIImage *)img {

UIGraphicsBeginImageContext(img.size);

CGRect aRectangle = CGRectMake(0,0, img.size.width, img.size.height);
[img drawInRect:aRectangle];

[[UIColor redColor] set];           // set text color
NSInteger fontSize = 14;
if ( [text length] > 200 ) {
    fontSize = 10;
}
UIFont *font = [UIFont boldSystemFontOfSize: fontSize];     // set text font

[ text drawInRect : aRectangle                      // render the text
         withFont : font
    lineBreakMode : UILineBreakModeTailTruncation  // clip overflow from end of last line
        alignment : UITextAlignmentCenter ];

UIImage *theImage=UIGraphicsGetImageFromCurrentImageContext();   // extract the image
UIGraphicsEndImageContext();     // clean  up the context.
return theImage;
}

从UIImageView创建UIImage

2 个答案: