記憶體映射文件MemoryMappedFile使用

參考資料： http://blog.csdn.net/bitfan/article/details/4438458

所謂記憶體映射文件，其實就是在記憶體中開闢出一塊存放數據的專用區域，這區域往往與硬碟上特定的文件相對應。進程將這塊記憶體區域映射到自己的地址空間中，訪問它就象是訪問普通的記憶體一樣。

在.NET中，使用MemoryMappedFile對象表示一個記憶體映射文件，通過它的CreateFromFile()方法根據磁碟現有文件創建記憶體映射文件，調用這一方法需要提供一個與磁碟現有文件相對應的FileStream對象。

需要保存的類：

[Serializable]
    public class MyImg
    {
        public Image img;
        public string name;
    }

MMF定義：

public class MMF
    {
        private MemoryMappedFile file = null;
        private MemoryMappedViewStream strem = null;
        private MemoryMappedViewAccessor acces = null;
        public MMF()
        {
            file = MemoryMappedFile.CreateOrOpen("myMMF", 1024 * 1024, MemoryMappedFileAccess.ReadWrite);
            strem = file.CreateViewStream();
            acces = file.CreateViewAccessor();
        }

        public void Write(int value)
        {
            acces.Write(0, value);
        }

        public int Read()
        {
            int value;
            acces.Read(0, out value);
            return value;
        }

        public void WriteClass(MyImg img)
        {
            IFormatter format = new BinaryFormatter();
            format.Serialize(strem, img);
        }

        public MyImg ReadClass()
        {
            IFormatter format = new BinaryFormatter();
            return format.Deserialize(strem) as MyImg;
        }
    }

界面代碼：

private void button1_Click(object sender, EventArgs e)
        {
            using (OpenFileDialog dlg = new OpenFileDialog())
            {
                dlg.Filter = "*.png|*.png";
                if (dlg.ShowDialog() == DialogResult.OK)
                {
                    this.pictureBox1.Image = Image.FromFile(dlg.FileName);
                    this.label1.Text = Path.GetFileNameWithoutExtension(dlg.FileName);
                }
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            MyImg img = new MyImg() { img = this.pictureBox1.Image, name = this.label1.Text };
            myFile.WriteClass(img);
        }

        private void button3_Click(object sender, EventArgs e)
        {
            MyImg img = myFile.ReadClass();

            this.pictureBox1.Image = img.img;
            this.label1.Text = img.name;
        }

        private void button4_Click(object sender, EventArgs e)
        {
            label2.Text = myFile.Read().ToString();
        }

        private void button5_Click(object sender, EventArgs e)
        {
            myFile.Write(int.Parse(this.textBox1.Text));
        }

參考資料： http://blog.csdn.net/bitfan/article/details/4438458