我正在将一个结构序列化为MemoryStream
,我想保存并加载序列化的结构。
那么,如何将a保存MemoryStream
到文件中并从文件中加载回来呢?
@Oded我应该使用什么?能给我举个例子?
—
Mahdi Ghiasi 2011年
我正在将一个结构序列化为MemoryStream
,我想保存并加载序列化的结构。
那么,如何将a保存MemoryStream
到文件中并从文件中加载回来呢?
Answers:
您可以使用MemoryStream.WriteTo
或Stream.CopyTo
(在框架版本4.5.2、4.5.1、4.5、4中受支持)方法将内存流的内容写入另一个流。
memoryStream.WriteTo(fileStream);
更新:
fileStream.CopyTo(memoryStream);
memoryStream.CopyTo(fileStream);
假设MemoryStream名称为ms
。
这段代码将MemoryStream记录到一个文件中:
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();
}
这会将文件读取到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,您可以简单地将FileStream复制到MemoryStream并如此简单地反向:
MemoryStream ms = new MemoryStream();
using (FileStream file = new FileStream("file.bin", FileMode.Open, FileAccess.Read))
file.CopyTo(ms);
和反向(MemoryStream到FileStream):
using (FileStream file = new FileStream("file.bin", FileMode.Create, System.IO.FileAccess.Write))
ms.CopyTo(file);
ms.ToArray()
函数来代替将内存流手动复制到数组中。
using (...){ }
具有完全相同的效果。
即使有异常(实际上很可能在文件I / O上),流也应该通过处理-使用子句是我最喜欢的方法,因此在编写MemoryStream时,可以使用:
using (FileStream file = new FileStream("file.bin", FileMode.Create, FileAccess.Write)) {
memoryStream.WriteTo(file);
}
并读回:
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,则值得注意的是,读取操作将使用的文件大小是文件总大小的两倍。一种解决方案是从字节数组创建MemoryStream-以下代码假定您随后将不写入该流。
MemoryStream ms = new MemoryStream(bytes, writable: false);
我的研究(如下)表明,内部缓冲区与您传递的是同一字节数组,因此应节省内存。
byte[] testData = new byte[] { 104, 105, 121, 97 };
var ms = new MemoryStream(testData, 0, 4, false, true);
Assert.AreSame(testData, ms.GetBuffer());
写入文件的组合答案可以是:
MemoryStream ms = new MemoryStream();
FileStream file = new FileStream("file.bin", FileMode.Create, FileAccess.Write);
ms.WriteTo(file);
file.Close();
ms.Close();
保存到文件
Car car = new Car();
car.Name = "Some fancy car";
MemoryStream stream = Serializer.SerializeToStream(car);
System.IO.File.WriteAllBytes(fileName, stream.ToArray());
从文件加载
using (var stream = new MemoryStream(System.IO.File.ReadAllBytes(fileName)))
{
Car car = (Car)Serializer.DeserializeFromStream(stream);
}
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;
}
}
}
最初,此类的实现已在此处发布
和
[Serializable]
public class Car
{
public string Name;
}
对于加载文件,我更喜欢
MemoryStream ms = new MemoryStream();
using (FileStream fs = File.OpenRead(file))
{
fs.CopyTo(ms);
}
我使用面板控件添加图像,甚至流视频,但是您可以将图像在SQL Server上另存为Image或将MySQL保存为largeblob。这段代码对我很有用。一探究竟。
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();
在这里可以加载,但是我使用了PictureBox控件。
MemoryStream ms = new MemoryStream(picarr);
ms.Seek(0, SeekOrigin.Begin);
fotos.pictureBox1.Image = System.Drawing.Image.FromStream(ms);
希望会有所帮助。
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);
MemoryStream
?