在C#中正确处理内存映射文件的方法

Question

我有以下测试代码：

const string filePath = @"c:\tests\mmap.bin";
const long k64 = 64 * 1024;

// create mmap file and accessor, then adquire pointer 
var fileStream = new FileStream(filePath, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite);
fileStream.SetLength(k64);

var mmap = MemoryMappedFile.CreateFromFile(fileStream, null, fileStream.Length,
    MemoryMappedFileAccess.ReadWrite,
    null, HandleInheritability.None, true);

var accessor = mmap.CreateViewAccessor(0, 0, MemoryMappedFileAccess.ReadWrite);
byte* pointer = null;
accessor.SafeMemoryMappedViewHandle.AcquirePointer(ref pointer);


// dispose accessor,  mmap file and stream
accessor.SafeMemoryMappedViewHandle.Close();
accessor.Dispose();
mmap.SafeMemoryMappedFileHandle.Close();
mmap.Dispose();
fileStream.Dispose();

// This causes UnauthorizedAccessException: 
// Access to the path 'c:\tests\mmap.bin' is denied
File.Delete(filePath);

它创建或打开 c:\tests\mmap.bin 文件，将其长度设置为64Kb，内存映射它，然后尝试释放所有资源。但并非所有资源都被释放，File.Delete(filePath) 失败。

如何正确释放内存映射文件所持有的所有资源？

- Jesús López

Answer 1

之后

accessor.SafeMemoryMappedViewHandle.AcquirePointer(ref pointer);

你需要调用

accessor.SafeMemoryMappedViewHandle.ReleasePointer();

用于清理。

- JeffRSon

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谢谢。我今天有点糊涂。 - Jesús López