如何从SQL Server数据库中检索图像。

问题描述：

我有一个代码将图像转换为字节数组并将其存储到数据库中。但我想基于id从数据库中检索图像。下面是将图像转换为字节数组的代码。

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I have a code that convert image into array of bytes and store it into database. But I want to retrieve an image from database based on id. Below is the code to convert image into array of bytes.
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private void convertImage()
   {
       if (FLUImg.HasFile)
       {

           try
           {
               int length = FLUImg.PostedFile.ContentLength;
               arrImg = new byte[length];
               HttpPostedFile img = FLUImg.PostedFile;
               img.InputStream.Read(arrImg, 0, length);

           }
           catch (Exception ex)
           {
               Response.Write("Error Uploading Image" + ex.ToString());
           }
       }
       else
       {
           Response.Write("Please select an image");
       }
   }

------------------------- ------------------

这里是使用数据集和datareader从数据库中检索图像的代码。但是图片没有加载。

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here is the code that retrieve image from database using dataset and datareader . But the image does not load.
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public void SportsMain()
   {
       try
       {
           con.Open();
           da = new SqlDataAdapter("SELECT TOP 1 *  from tbl_news_details where cid=2 order by nid desc", con);
           DataTable dt = new DataTable();
           da.Fill(dt);
           DataListSports.DataSource = dt;
           DataListSports.DataBind();
           con.Close();
       }
       catch (Exception ex) { }
   }

-----------------------------------------

Datareader代码

----------------------------------------- -

-----------------------------------------
Datareader Code
------------------------------------------

con.open();
 ss = "SELECT * FROM tbl_news_details WHERE nid='" + max + "'";
            cmd = new SqlCommand(ss, con);
            dr = cmd.ExecuteReader();
            dr.Read();
            if(dr.HasRows)
            {
                num1 = Convert.ToInt16(dr["nid"]);
                lblTitle1.Text = dr["title"].ToString();
                img1 = (Image)dr["img"];
            }
            dr.Close();
            con.Close();

答

从数据库中获取字节数组时，可以将其写入文件并使用该文件作为图像的ImageUrl。

所以类似于：

When fetching the byte array from the database, you can write it into a file and the use that file as the ImageUrl for the image.

So something like:

byte[] imageBytes = dr["img"] as byte[];
string fileName = @"SOME LOCATION\" + System.DateTime.Now.Ticks.ToString() + ".jpg"; // whatever is the proper location and type for the file
using (System.IO.FileStream imageFile = new System.IO.FileStream(fileName, System.IO.FileMode.CreateNew)) {
   imageFile.Write(imageBytes, 0, imageBytes.Length);
   imageFile.Flush();
   imageFile.Close();
}
img1.ImageUrl = fileName;

如何从SQL Server数据库中检索图像。

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