iPhone - 获取一个指针背后CGDataProvider数据？ [英] iPhone - Get a pointer to the data behind CGDataProvider?

问题描述

我试图采取CGImage和它的数据复制到供以后处理的缓冲区。下面的code是什么，我有这么远，但有一件事我不喜欢它 - 它的两次复制图像数据。一旦 CGDataProviderCopyData（），一次用于：的getBytes：上imgData长度电话。我一直没能找到一种方法将图像数据直接复制到我的缓冲区，并切出的 CGDataProviderCopyData（）一步，但必须有一个方式.. .ANY指针？ （双关语... FTW）

的NSData * imgData =（NSData的*）（CGDataProviderCopyData（CGImageGetDataProvider（myCGImageRef）））;CGImageRelease（myCGImageRef）;//我得pviously定义指针到一个可用缓冲器$ P $称为mybuff
[imgData的getBytes：长度mybuff：imgData长度]];

解决方案

看到这个答案：
<一href=\"http://stackoverflow.com/questions/2744639/cocoa-does-cgdataprovidercopydata-actually-copy-the-bytes-or-just-the-point\">http://stackoverflow.com/questions/2744639/cocoa-does-cgdataprovidercopydata-actually-copy-the-bytes-or-just-the-point

看起来直接进入后面的CGDataProvider缓冲区仅限于私人的API。

I'm trying to take a CGImage and copy its data into a buffer for later processing. The code below is what I have so far, but there's one thing I don't like about it - it's copying the image data twice. Once for CGDataProviderCopyData() and once for the :getBytes:length call on imgData. I haven't been able to find a way to copy the image data directly into my buffer and cut out the CGDataProviderCopyData() step, but there has to be a way...any pointers? (...pun ftw)

NSData *imgData = (NSData *)(CGDataProviderCopyData(CGImageGetDataProvider(myCGImageRef)));

CGImageRelease(myCGImageRef);

// i've got a previously-defined pointer to an available buffer called "mybuff"
[imgData getBytes:mybuff length:[imgData length]];

解决方案

See this answer: http://stackoverflow.com/questions/2744639/cocoa-does-cgdataprovidercopydata-actually-copy-the-bytes-or-just-the-point

Looks like direct access to the buffer behind a CGDataProvider is restricted to private APIs.

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