之类的话题中：我想从一个文件（从流）数据读入内存中（的MemoryStream），以提高我的应用程序的速度。怎么办呢？

Like in the topic: I want to read data from a file (from stream) into memory (memorystream) to improve my app speed. How to do it?

推荐答案

有几个选项：

阅读这一切变成一个字节数组第一...

byte[] data = File.ReadAllBytes(file);
MemoryStream stream = new MemoryStream(data);

或使用.NET 4的CopyTo方法

MemoryStream memoryStream = new MemoryStream();
using (Stream input = File.OpenRead(file))
{
    input.CopyTo(memoryStream);
}
memoryStream.Position = 0;

或做手工

MemoryStream memoryStream = new MemoryStream();
using (Stream input = File.OpenRead(file))
{
    byte[] buffer = new byte[32 * 1024]; // 32K buffer for example
    int bytesRead;
    while ((bytesRead = input.Read(buffer, 0, buffer.Length)) > 0)
    {
        memoryStream.Write(buffer, 0, bytesRead);
    }
}
memoryStream.Position = 0;