我可以创建一个NSURL来引用内存中的NSData吗?

The docs for NSURL state that:

NSURL的文档说明:

An NSURL object represents a URL that can potentially contain the location of a resource on a remote server, the path of a local file on disk, or even an arbitrary piece of encoded data.

NSURL对象表示一个URL，该URL可能包含远程服务器上资源的位置、磁盘上本地文件的路径，甚至是任意编码的数据。

I have a blob of in-memory data that I'd like to hand to a library that wants to load a resource via an NSURL. Sure, I can first write this NSData to a temp file and then create a file:// NSURL from that, but I'd prefer to have the URL point directly to the buffer that I already have present in memory.

我有一团内存中的数据，我想把它们交给一个想通过NSURL加载资源的库。当然，我可以先将这个NSData写到一个临时文件中，然后从中创建一个文件:// NSURL，但是我更希望URL点直接指向内存中已经存在的缓冲区。

The docs quoted above seem to suggest this is possible, but I can't find any hint of how to accomplish it. Am I missing something?

上面引用的文档似乎表明这是可能的，但是我找不到任何关于如何实现它的提示。我遗漏了什么东西?

2 个解决方案

#1

NSURL supports the data:// URL-Scheme (RFC 2397).
This scheme allows you to build URLs in the form of

NSURL支持数据:// URL-Scheme (RFC 2397)。该方案允许您以表单的形式构建url。

data://data:MIME-Type;base64,<data>

A working Cocoa example would be:

一个可用的可可示例是:

NSImage* img = [NSImage imageNamed:@"img"];
NSData* imgData = [img TIFFRepresentation];
NSString* dataFormatString = @"data:image/png;base64,%@";
NSString* dataString = [NSString stringWithFormat:dataFormatString, [imgData base64EncodedStringWithOptions:0]];
NSURL* dataURL = [NSURL URLWithString:dataString];

Passing around large binary blobs with data URLs might be a bit inefficient due to the nature of base64 encoding.

由于base64编码的特性，使用数据url传递大型二进制blobs可能有点低效。

You could also implement a custom NSURLProtocol that specifically deals with your data. Apple has some sample code that uses a custom protocol to pass around image objects: https://developer.apple.com/library/mac/samplecode/SpecialPictureProtocol/Introduction/Intro.html#//apple_ref/doc/uid/DTS10003816

还可以实现专门处理数据的自定义NSURLProtocol。苹果有一些使用自定义协议来传递图像对象的示例代码:https://developer.apple.com/library/mac/samplecode/specialpicturetionprotocol / introduction / intro.html #/ apple_ref/doc/uid/DTS10003816

#2

What you are missing is the NSURLProtocol class. Takes about three dozen lines of code, and any code that handles URLs properly can access your in-memory data. Read the documentation, it's not difficult and there is sample code available.

您所缺少的是NSURLProtocol类。大约需要36行代码，任何正确处理url的代码都可以访问内存中的数据。阅读文档，这并不困难，并且有可用的示例代码。

Unfortunately there are some APIs that take an NSURL as a parameter, but can only handle file URLs.

不幸的是，有些api以NSURL作为参数，但只能处理文件url。

#1