C# 将图像文件保存到 sql Server 并将字节数组转换为图像
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/8880213/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Saving an Image file to sql Server and converting byte array into image
提问by nick gowdy
I am storing images in a database and would like to convert them from byte array to image. I have no problem converting an object to byte array but I get an error of "Parameter is not valid" when trying to convert from byte array to image. The object I am passing to my method is from a dataset row.
我将图像存储在数据库中，并希望将它们从字节数组转换为图像。我将对象转换为字节数组没有问题，但是在尝试从字节数组转换为图像时出现“参数无效”错误。我传递给我的方法的对象来自数据集行。
Stored procedure
存储过程
USE [----------------]
GO
/****** Object: StoredProcedure [dbo].[usp_imageloader_add_test] Script Date: 01/16/2012 09:19:46 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER procedure [dbo].[usp_imageloader_add_test]
@p_Image Image
as
INSERT into Test_Images VALUES(@p_Image)
Upload File control/convert Image file to byte array and save data to database
上传文件控制/将图像文件转换为字节数组并将数据保存到数据库
protected void btnUpload_Click(object sender, EventArgs e)
{
if (ctrlUpload.PostedFile != null)
{
if (ctrlUpload.PostedFile.ContentLength > 0)
{
// Get Posted File
HttpPostedFile objHttpPostedFile = ctrlUpload.PostedFile;
// Find its length and convert it to byte array
int ContentLength = objHttpPostedFile.ContentLength;
// Create Byte Array
byte[] bytImg = new byte[ContentLength];
// Read Uploaded file in Byte Array
objHttpPostedFile.InputStream.Read(bytImg, 0, ContentLength);
using (SqlConnection dbConnection = new SqlConnection(app_settings.sql_conn_string_db))
{
try
{
string sql = "usp_imageloader_add_test";
SqlCommand cmd = new SqlCommand(sql, dbConnection);
cmd.CommandType = System.Data.CommandType.StoredProcedure;
cmd.Parameters.AddWithValue("@p_Image", bytImg).SqlDbType = SqlDbType.Binary;
cmd.Connection.Open();
cmd.ExecuteNonQuery();
cmd.Connection.Close();
}
catch (Exception ex)
{
ex.Message.ToString();
}
}
}
}
}
Table method which calls objToImg method
调用 objToImg 方法的表格方法
protected void Page_Load(object sender, EventArgs e)
{
generateTable(false);
}
private Table generateTable(bool flag)
{
Table tb = BuildList(GetData(), flag);
if (imgloadercms != null)
{
PlaceHolder ph = new PlaceHolder();
StringBuilder sb = new StringBuilder();
ph.Controls.Add(new LiteralControl(sb.ToString()));
}
imgloadercms.Controls.Add(tb);
return tb;
}
protected Table BuildList(DataTable tb, bool flag)
{
Table tblImageLibrary = new Table();
tblImageLibrary.BorderStyle = BorderStyle.Solid;
tblImageLibrary.BorderWidth = Unit.Pixel(8);
if (tb.Rows.Count > 0)
{
try
{
if (!flag)
{
tblImageLibrary.BorderColor = Color.Black;
tblImageLibrary.BorderWidth = Unit.Pixel(1);
TableRow tr = new TableRow(); // Table row for header of table
tr.BackColor = Color.LightBlue;
TableCell c1 = new TableCell();
TableCell c2 = new TableCell();
c1.Controls.Add(new LiteralControl("Image Id"));
tr.Cells.Add(c1);
c2.Controls.Add(new LiteralControl("Image"));
tr.Cells.Add(c2);
tblImageLibrary.Rows.Add(tr);
}
int i = 0;
foreach (DataRow r in tb.Rows) // Create new row foreach row in table
{
TableRow tr = new TableRow();
if (i % 2 == 0)
{
tr.BackColor = Color.LightYellow;
}
// Build cells
TableCell c1 = new TableCell();
TableCell c2 = new TableCell();
c2.Width = 300;
c1.Controls.Add(new LiteralControl(r["Image_Id"].ToString()));
tr.Cells.Add(c1);
// Call method to serialize obj to byte array
//System.Drawing.Image dbImg =
ObjToImg(r["Image_File"]);
}
catch (Exception ex)
{
ex.ToString();
}
if (!flag)
{
}
}
return tblImageLibrary;
}
Return Image
返回图像
private System.Drawing.Image ObjToImg(object obj)
{
//byte[] byteArray = null;
if (obj == null)
return null;
else
{
BinaryFormatter bf = new BinaryFormatter();
using (MemoryStream ms = new MemoryStream())
{
bf.Serialize(ms, obj); //now in Memory Stream
ms.ToArray(); // Array object
ms.Seek(0, SeekOrigin.Begin);
//return (System.Drawing.Image)bf.Deserialize(ms);
System.Drawing.Image myImage = (System.Drawing.Image)bf.Deserialize(ms);
return myImage;
}
Whenever I try to add the memory stream object to the image object constructor I get the error message of "Parameter is not valid". Maybe I made a mistake when insert the byte array into the database because I have looked at other code and it doesn't make sense how it's not working.
每当我尝试将内存流对象添加到图像对象构造函数时，我都会收到“参数无效”的错误消息。也许我在将字节数组插入数据库时犯了一个错误，因为我已经查看了其他代码并且它不工作是没有意义的。
回答by Oleg Dok
Try to deserializethe object first from byte array with your BinaryFormatter!
尝试首先使用 BinaryFormatter 从字节数组中反序列化对象！
Try to use following two methods:
尝试使用以下两种方法：
private System.Drawing.Image ObjToImg(byte[] obj)
{
if (obj == null)
return null;
else
{
BinaryFormatter bf = new BinaryFormatter();
using(MemoryStream ms = new MemoryStream(obj))
{
return (System.Drawing.Image)bf.Deserialize(ms);
}
}
}
private byte[] ImgToObj(System.Drawing.Image obj)
{
if (obj == null)
return null;
else
{
BinaryFormatter bf = new BinaryFormatter();
using(MemoryStream ms = new MemoryStream())
{
bf.Serialize(ms, obj);
return ms.ToArray();
}
}
}
回答by TheSmartWon
I just recently had to do the exact same thing in VB.NET. Here is my code, run through Telerik's Code Converter. It was quite tricky to get working, and is still honestly a pain.
我最近不得不在 VB.NET 中做完全相同的事情。这是我的代码，通过 Telerik 的代码转换器运行。开始工作非常棘手，老实说仍然很痛苦。
To upload an image:
上传图片：
private bool uploadImage(ref Bitmap p)
{
SqlConnection con = new SqlConnection();
con.ConnectionString = Configuration.ConfigurationManager.ConnectionStrings("ConnStringHere").ConnectionString;
SqlCommand cmd = new SqlCommand();
cmd.CommandText = "INSERT INTO Table_Name (File2) VALUES (@File2)"; //I named the column File2 simply because "File" seemed to be a keyword in SQLServer
cmd.CommandType = CommandType.Text;
cmd.Connection = con;
SqlParameter File1 = new SqlParameter("@File2", SqlDbType.Image);
MemoryStream ms = new MemoryStream();
using (Bitmap tempImage = new Bitmap(p))
{
tempImage.Save(ms, p.RawFormat);
}
byte[] data = ms.GetBuffer();
if (!isValidImage(data)) //optional, will include code if requested.
{
return false;
}
File1.Value = data;
cmd.Parameters.Add(File1);
con.Open();
int result = cmd.ExecuteNonQuery();
if (result > 0)
{
// SUCCESS!
con.Close();
return true;
}
else
{
//failure
con.Close();
return false;
}
}
To retrieve an image:
要检索图像：
private Bitmap retrieveBitmap()
{
Image image1 = null
if (dt1.Rows.Count > 0)
{
byte[] imageData1 = null;
if (dt1[0].Count > 0)
{
if (!Information.IsDBNull(dt1.CopyToDataTable()[0].Item("File2")))
{
imageData1 = (byte[])dt1.CopyToDataTable()[0].Item("File2");
}
}
if ((imageData1 != null))
{
if (isValidImage(imageData1))
{
using (MemoryStream ms = new MemoryStream(imageData1, 0, imageData1.Length))
{
ms.Write(imageData1, 0, imageData1.Length);
image1 = Image.FromStream(ms, true);
}
return image1;
}
else
{
// "Invalid image on server";
return null;
}
}
}
}
My code may need small formatting changes, please edit whatever has invalid syntax (my C# is a little rusty, and my code was run through a converter).
我的代码可能需要小的格式更改，请编辑任何无效语法（我的 C# 有点生疏，我的代码是通过转换器运行的）。
