在文件中保存和加載 MemoryStream

Question

我正在將一個結構序列化為MemoryStream並且我想保存和加載序列化的結構。

那么，如何將MemoryStream保存到文件中並從文件中加載回來？

Answer 1

您可以使用MemoryStream.WriteTo或Stream.CopyTo （框架版本Stream.CopyTo支持）方法將內存流的內容寫入另一個流。

memoryStream.WriteTo(fileStream);

更新：

fileStream.CopyTo(memoryStream);
memoryStream.CopyTo(fileStream);

Answer 2

假設 MemoryStream 名稱是ms 。

此代碼將 MemoryStream 寫入文件：

using (FileStream file = new FileStream("file.bin", FileMode.Create, System.IO.FileAccess.Write)) {
   byte[] bytes = new byte[ms.Length];
   ms.Read(bytes, 0, (int)ms.Length);
   file.Write(bytes, 0, bytes.Length);
   ms.Close();
}

並將文件讀取到 MemoryStream ：

using (MemoryStream ms = new MemoryStream())
using (FileStream file = new FileStream("file.bin", FileMode.Open, FileAccess.Read)) {
   byte[] bytes = new byte[file.Length];
   file.Read(bytes, 0, (int)file.Length);
   ms.Write(bytes, 0, (int)file.Length);
}

在 .Net Framework 4+ 中，您可以簡單地將 FileStream 復制到 MemoryStream 並像這樣簡單地反向：

MemoryStream ms = new MemoryStream();
using (FileStream file = new FileStream("file.bin", FileMode.Open, FileAccess.Read))
    file.CopyTo(ms);

反過來（MemoryStream 到 FileStream）：

using (FileStream file = new FileStream("file.bin", FileMode.Create, System.IO.FileAccess.Write))
    ms.CopyTo(file);

Answer 3

即使有異常（很可能在文件 I/O 上），流也應該真的被處理掉 - using 子句是我最喜歡的方法，所以為了編寫你的 MemoryStream，你可以使用：

using (FileStream file = new FileStream("file.bin", FileMode.Create, FileAccess.Write)) {
    memoryStream.WriteTo(file);
}

並閱讀它：

using (FileStream file = new FileStream("file.bin", FileMode.Open, FileAccess.Read)) {
    byte[] bytes = new byte[file.Length];
    file.Read(bytes, 0, (int)file.Length);
    ms.Write(bytes, 0, (int)file.Length);
}

如果文件很大，那么值得注意的是，讀取操作將使用兩倍於總文件大小的內存。 對此的一種解決方案是從字節數組創建 MemoryStream - 以下代碼假定您隨后不會寫入該流。

MemoryStream ms = new MemoryStream(bytes, writable: false);

我的研究（如下）表明內部緩沖區與您傳遞的字節數組相同，因此它應該節省內存。

byte[] testData = new byte[] { 104, 105, 121, 97 };
var ms = new MemoryStream(testData, 0, 4, false, true);
Assert.AreSame(testData, ms.GetBuffer());

Answer 4

對於任何尋找簡短版本的人：

var memoryStream = new MemoryStream(File.ReadAllBytes("1.dat"));

File.WriteAllBytes("1.dat", memoryStream.ToArray()); 

Answer 5

寫入文件的組合答案可以是；

MemoryStream ms = new MemoryStream();    
FileStream file = new FileStream("file.bin", FileMode.Create, FileAccess.Write);
ms.WriteTo(file);
file.Close();
ms.Close();

Answer 6

保存到文件中

Car car = new Car();
car.Name = "Some fancy car";
MemoryStream stream = Serializer.SerializeToStream(car);
System.IO.File.WriteAllBytes(fileName, stream.ToArray());

從文件加載

using (var stream = new MemoryStream(System.IO.File.ReadAllBytes(fileName)))
{
    Car car = (Car)Serializer.DeserializeFromStream(stream);
}

在哪里

using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;

namespace Serialization
{
    public class Serializer
    {
        public static MemoryStream SerializeToStream(object o)
        {
            MemoryStream stream = new MemoryStream();
            IFormatter formatter = new BinaryFormatter();
            formatter.Serialize(stream, o);
            return stream;
        }

        public static object DeserializeFromStream(MemoryStream stream)
        {
            IFormatter formatter = new BinaryFormatter();
            stream.Seek(0, SeekOrigin.Begin);
            object o = formatter.Deserialize(stream);
            return o;
        }
    }
}

原來這個類的實現已經貼在這里了

和

[Serializable]
public class Car
{
    public string Name;
}

Answer 7

對於加載文件，我更喜歡這個

MemoryStream ms = new MemoryStream();
using (FileStream fs = File.OpenRead(file))
{
    fs.CopyTo(ms);
}

Answer 8

我使用面板控件添加圖像甚至流視頻，但您可以將 SQL Server 上的圖像另存為Image或將 MySQL 保存為largeblob 。 這段代碼對我很有用。 一探究竟。

在這里你保存圖像

MemoryStream ms = new MemoryStream();
Bitmap bmp = new Bitmap(panel1.Width, panel1.Height);
panel1.DrawToBitmap(bmp, panel1.Bounds);
bmp.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg); // here you can change the Image format
byte[] Pic_arr = new byte[ms.Length];
ms.Position = 0;
ms.Read(Pic_arr, 0, Pic_arr.Length);
ms.Close();

在這里你可以加載，但我使用了一個圖片框控件。

MemoryStream ms = new MemoryStream(picarr);
ms.Seek(0, SeekOrigin.Begin);
fotos.pictureBox1.Image = System.Drawing.Image.FromStream(ms);

希望有所幫助。

Answer 9

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Text;

namespace ImageWriterUtil
{
    public class ImageWaterMarkBuilder
    {
        //private ImageWaterMarkBuilder()
        //{
        //}
        Stream imageStream;
        string watermarkText = "©8Bytes.Technology";
        Font font = new System.Drawing.Font("Brush Script MT", 30, FontStyle.Bold, GraphicsUnit.Pixel);
        Brush brush = new SolidBrush(Color.Black);
        Point position;
        public ImageWaterMarkBuilder AddStream(Stream imageStream)
        {
            this.imageStream = imageStream;
            return this;
        }
        public ImageWaterMarkBuilder AddWaterMark(string watermarkText)
        {
            this.watermarkText = watermarkText;
            return this;
        }
        public ImageWaterMarkBuilder AddFont(Font font)
        {
            this.font = font;
            return this;
        }

        public ImageWaterMarkBuilder AddFontColour(Color color)
        {
            this.brush = new SolidBrush(color);
            return this;
        }
        public ImageWaterMarkBuilder AddPosition(Point position)
        {
            this.position = position;
            return this;
        }

        public void CompileAndSave(string filePath)
        {

            //Read the File into a Bitmap.
            using (Bitmap bmp = new Bitmap(this.imageStream, false))
            {
                using (Graphics grp = Graphics.FromImage(bmp))
                {


                    //Determine the size of the Watermark text.
                    SizeF textSize = new SizeF();
                    textSize = grp.MeasureString(watermarkText, font);

                    //Position the text and draw it on the image.
                    if (position == null)
                        position = new Point((bmp.Width - ((int)textSize.Width + 10)), (bmp.Height - ((int)textSize.Height + 10)));
                    grp.DrawString(watermarkText, font, brush, position);

                    using (MemoryStream memoryStream = new MemoryStream())
                    {
                        //Save the Watermarked image to the MemoryStream.
                        bmp.Save(memoryStream, ImageFormat.Png);
                        memoryStream.Position = 0;
                       // string fileName = Path.GetFileNameWithoutExtension(filePath);
                        // outPuthFilePath = Path.Combine(Path.GetDirectoryName(filePath), fileName + "_outputh.png");
                        using (FileStream file = new FileStream(filePath, FileMode.Create, System.IO.FileAccess.Write))
                        {
                            byte[] bytes = new byte[memoryStream.Length];
                            memoryStream.Read(bytes, 0, (int)memoryStream.Length);
                            file.Write(bytes, 0, bytes.Length);
                            memoryStream.Close();
                        }
                    }
                }
            }

        }
    }
}

用法 ：-

ImageWaterMarkBuilder.AddStream(stream).AddWaterMark("").CompileAndSave(filePath);