如何将NSString转换为UIImage以用于appengine blobstore [英] How to convert NSString to UIImage for appengine blobstore

问题描述

当我执行以下操作时，生成的图像为空

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

我该如何做到这一点？

原因

我需要将图片从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。 AFHTTPRequestOperationManager后多部分请求不工作

解决方案

下面是从NSString生成图像的代码..

$ p $ +（ 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;



调用此方法，如...

  UIImage * image; 
 image = [self imageFromText：@Good morning]; 
 //根据您的要求使用此图片
  

我希望它适合你。

when I do the following the resulting image is null

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);

How might I do this well?

Reason

I need to save an image from iOS to the Google blobstore. I need to include some metadata with the image. When I encode the string as base64 it does not work.

This is loosely a follow up to AFHTTPRequestOperationManager post multi-part request not working

解决方案

Here is the code for generating image from NSString..

Implement this method....

 +(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;
}

Call this method like...

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

I hope it work for you..

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