iPhone-释放CGDataProviderRef时会破坏动态字段吗

Question

I have created CGDataProviderRef, and one of parameters is array of pixels. When I release provider, do i also have to free memory, or is provider doing it itself?

pixels = (Byte *) malloc([data length] * sizeof (Byte));   
CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, pixels, [data length], NULL);

Basically, do i have to call:

[provider release];
[free pixels];

Answer 1

When you already have your data in an NSData object you can instead use CGDataProviderCreateWithCFData, so you don't have to malloc and copy the pixels.

If you insist on using a malloc'd array you can provide a callback that is called when the data provider is released like this:

void freePixels(void *info, const void *data, size_t size) {
    free((void*)data);
}

CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, pixels, [data length], freePixels);