ios - 如何将NSString转换为Appengine Blobstore的UIImage

Question

当我执行以下操作时，生成的图像为空

NSLog(@"string (%@) to base64NSData",object);
NSData *base64Data = [[object dataUsingEncoding:NSUTF8StringEncoding] base64EncodedDataWithOptions:0];
NSLog(@"NSData (%@) to UIImage",base64Data);
UIImage *image = [UIImage imageWithData:base64Data];
NSLog(@"my image is: %@",image);

我怎么做得好？

原因

我需要将图像从iOS保存到Google Blobstore。我需要在图像中包含一些元数据。当我将字符串编码为base64时，它不起作用。

这是对 AFHTTPRequestOperationManager post multi-part request not working的大致跟踪

Answer 1

这是用于从NSString生成图像的代码。

实现此方法...。

 +(UIImage *)imageFromText:(NSString *)text
 {
    UIFont *font = [UIFont systemFontOfSize:20.0];
    CGSize size = [text sizeWithAttributes:
               @{NSFontAttributeName:
                     [UIFont systemFontOfSize:20.0f]}];
      if (UIGraphicsBeginImageContextWithOptions != NULL)
        UIGraphicsBeginImageContextWithOptions(size,NO,0.0);
   else
       UIGraphicsBeginImageContext(size);

[text drawAtPoint:CGPointMake(0.0, 0.0) withFont:font];
   //    [text drawAtPoint:CGPointMake(0.0, 0.0) forWidth:CGPointMake(0, 0) withFont:font fontSize:nil lineBreakMode:NSLineBreakByWordWrapping baselineAdjustment:NSTextAlignmentCenter];

UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

 return image;
}

像这样调用此方法

  UIImage *image;
  image = [self imageFromText:@"Good Morning];
  //Use this image as per your requirement 

希望它对您有用。