使用NSData不形成UIImage对象

Question

我从服务器收到以下回复：

{
    "userId": "72e823ebc0c07fa99f279d6435e2c6ce",
    "userHash": null,
    "md5": "e993b7e9ec74bcdc1b1b7baec7d1cdd2",
    "highres": null,
    "thumbnail": "/9j/4AAQSkZJRgABAgAAAQABAAD/2wBDAAgGBgcGBQgHBwcJCQgKDBQNDAsLDBkSEw8UHRofHh0aHBwgJC4nICIsIxwcKDcpLDAxNDQ0
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}

缩略图是一个字节数组，我想将其转换为NSData，然后转换为UIImage。

当我执行以下操作时，我最终得到的是nil：

  NSData *pictureData = [NSData dataWithBytes:[updatedData objectForKey:@"thumbnail"]];

  UIImage *img = [[UIImage alloc] initWithData:pictureData];

我该如何解决这个问题？

Answer 1

这不是“字节数组”。这是一个包含Base64编码图像的NSString。

iOS7内置支持Base64编码数据，对于旧版本，您必须自行编写代码。有很多可用的实现

这适用于iOS7：

//    NSString *base64String = [updatedData objectForKey:@"thumbnail"];
    NSString *base64String = @"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";

    NSData *data = [[NSData alloc] initWithBase64EncodedString:base64String options:NSDataBase64DecodingIgnoreUnknownCharacters];
    UIImage *image = [UIImage imageWithData:data];

这就是你的形象：