内存映射文件MemoryMappedFile使用

时间:2021-03-04 19:46:57

参考资料: http://blog.csdn.net/bitfan/article/details/4438458

所谓内存映射文件,其实就是在内存中开辟出一块存放数据的专用区域,这区域往往与硬盘上特定的文件相对应。进程将这块内存区域映射到自己的地址空间中,访问它就象是访问普通的内存一样。

在.NET中,使用MemoryMappedFile对象表示一个内存映射文件,通过它的CreateFromFile()方法根据磁盘现有文件创建内存映射文件,调用这一方法需要提供一个与磁盘现有文件相对应的FileStream对象。

需要保存的类:

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

MMF定义:

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

界面代码:

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));
}

参考资料: http://blog.csdn.net/bitfan/article/details/4438458