我正在序列化一个结构到MemoryStream，我想保存和加载序列化结构。
那么，如何保存一个MemoryStream到一个文件，也从文件加载回来?
当前回答
假设MemoryStream名称为ms。
这段代码将MemoryStream写入一个文件:
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();
}
它将一个文件读到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，你可以简单地将FileStream复制到MemoryStream中，并像下面这样简单地反向:
MemoryStream ms = new MemoryStream();
using (FileStream file = new FileStream("file.bin", FileMode.Open, FileAccess.Read))
file.CopyTo(ms);
和反向(内存流到文件流):
using (FileStream file = new FileStream("file.bin", FileMode.Create, System.IO.FileAccess.Write))
ms.CopyTo(file);
其他回答
对于加载文件，我更喜欢这个
MemoryStream ms = new MemoryStream();
using (FileStream fs = File.OpenRead(file))
{
fs.CopyTo(ms);
}
假设MemoryStream名称为ms。
这段代码将MemoryStream写入一个文件:
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();
}
它将一个文件读到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，你可以简单地将FileStream复制到MemoryStream中，并像下面这样简单地反向:
MemoryStream ms = new MemoryStream();
using (FileStream file = new FileStream("file.bin", FileMode.Open, FileAccess.Read))
file.CopyTo(ms);
和反向(内存流到文件流):
using (FileStream file = new FileStream("file.bin", FileMode.Create, System.IO.FileAccess.Write))
ms.CopyTo(file);
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);
我使用面板控件来添加图像甚至流视频，但您可以将图像保存在SQL Server为image或MySQL为largeblob。这个代码对我很有用。来看看。
在这里保存图像
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();
这里你可以加载，但我用的是PictureBox Control。
MemoryStream ms = new MemoryStream(picarr);
ms.Seek(0, SeekOrigin.Begin);
fotos.pictureBox1.Image = System.Drawing.Image.FromStream(ms);
希望有帮助。
即使有异常(很可能在文件I/O上)，流也应该被处理掉-使用子句是我最喜欢的方法，所以为了写你的MemoryStream，你可以使用:
using (FileStream file = new FileStream("file.bin", FileMode.Create, FileAccess.Write)) {
memoryStream.WriteTo(file);
}
对于读回它:
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，读取操作将使用的内存是总文件大小的两倍。一种解决方案是从字节数组创建MemoryStream -下面的代码假设您不会写入该流。
MemoryStream ms = new MemoryStream(bytes, writable: false);
我的研究(如下)表明，内部缓冲区是相同的字节数组，因为你传递它，所以它应该节省内存。
byte[] testData = new byte[] { 104, 105, 121, 97 };
var ms = new MemoryStream(testData, 0, 4, false, true);
Assert.AreSame(testData, ms.GetBuffer());
