C#的獨立存儲器和映射內存

獨立存儲器和映射內存都是用來處理程序數據問題。獨立存儲器可以用來臨時保存程序的一些不重要數據 ，映射內存文件則可以用來解決程序數據讀取的問題。當程序在運行過程中需要加載大量的外部數據時，用它 來做一個數據緩存區域將是一個不錯的選擇。

獨立存儲器

static void UserIsolationFile()  
      
{  
      
//this file was saved into the path: C:\Users\you account\AppData\Local\IsolatedStorage
    IsolatedStorageFile storFile = IsolatedStorageFile.GetUserStoreForDomain();  
      
    IsolatedStorageFileStream storStream = new IsolatedStorageFileStream("storagefile.txt", 

FileMode.Create, FileAccess.Write);  

    StreamWriter writer = new StreamWriter(storStream);  
      
    writer.WriteLine("You are dead!");  
      
    writer.Flush();  
      
    writer.Close();  
      
    storStream.Close();  
      
    storFile.Close();  

    IsolatedStorageFile storFile2 = IsolatedStorageFile.GetUserStoreForDomain();  
      
    string[] filenames = storFile2.GetFileNames();  

    foreach (string filename in filenames)  
      
    {  
      
        if (filename != "storagefile.txt")  
      
        {  
      
            continue;  
      
        }  
      
        using (IsolatedStorageFileStream stream = new
      
    IsolatedStorageFileStream("storagefile.txt", FileMode.Open))  
      
        {  
      
            using (StreamReader reader = new StreamReader(stream))  
      
            {  
      
                Console.WriteLine(reader.ReadToEnd());  
      
            }  
      
        }  
      
    }  
      
    Console.ReadKey();  
      
}

映射內存

這個東西怎麼感覺很像C呀，哈哈。如有程序需要頻繁的讀寫文本類文件可以這它來做一 個讀寫緩存提高程序的效率。

static void MappingMemory()  
      
{   
      
using(var mmFile=MemoryMappedFile.CreateFromFile("d:\\mappingmemory.txt"
      
,FileMode.Create  
      
,"fileHandle",1024*1024))  
      
    {  
      
        string valueToWrite = "Written to the mapped-memory file on "+ DateTime.Now.ToString();  
      
        var myAccessor = mmFile.CreateViewAccessor();  

        myAccessor.WriteArray<byte>(0, Encoding.ASCII.GetBytes(valueToWrite), 0  
      
, valueToWrite.Length);  

        var readOut = new byte[valueToWrite.Length];  
      
        myAccessor.ReadArray<byte>(0, readOut, 0, readOut.Length);  
      
        Console.WriteLine("The data is:" + Encoding.ASCII.GetString(readOut));  
      
        Console.ReadKey();  

    }  

}