. Net image Access Technology in SQL Server)

This article summarizes how to save images to SQL Server in. Net winform and. Net webform (Asp.net) and read the display method.
1. Use Asp.net to upload images and store them in SQL Server. Then, read and display the images from SQL Server:
1) Upload and store the data to SQL Server
Database Structure
Create Table Test
{
Id identity (1, 1 ),
Fimage Image
}
Related stored procedures
Create proc updateimage
(
@ Updateimage Image
)
As
Insert into test (fimage) values (@ updateimage)
Go adds the following to the upphoto. aspx file:
<Input id = "upphoto" name = "upphoto" runat = "server" type = "file">
<Asp: button id = "btnadd" name = "btnadd" runat = "server" text = "Upload"> </ASP: button> Code File upphoto. aspx. CS add btnadd button click event processing code:
Private void btnadd_click (Object sender, system. eventargs E)
{
// Obtain the image and convert the image to byte []
Httppostedfile upphoto = upphoto. postedfile;
Int upphotolength = upphoto. contentlength;
Byte [] photoarray = new byte [upphotolength];
Stream photostream = upphoto. inputstream;
Photostream. Read (photoarray, 0, upphotolength); // connect to the database
Sqlconnection conn = new sqlconnection ();
Conn. connectionstring = "Data Source = localhost; database = test; user id = sa; Pwd = sa"; sqlcommand cmd = new sqlcommand ("updateimage", Conn );
Cmd. commandtype = commandtype. storedprocedure; cmd. Parameters. Add ("@ updateimage", sqldbtype. Image );
Cmd. Parameters ["@ updateimage"]. value = photoarray; // if you do not want to use the stored procedure to add an image, change the above four sentences:
// String strsql = "insert into test (fimage) values (@ fimage )";
// Sqlcommand cmd = new sqlcommand (strsql, Conn );
// Cmd. Parameters. Add ("@ fimage", sqldbtype. Image );
// Cmd. Parameters ["@ fimage"]. value = photoarray; Conn. open ();
Cmd. executenonquery ();
Conn. Close ();
} 2) read and display from SQL Server
Add the following code to the image display area:
<Asp: Image id = "imgphoto" runat = "server" imageurl = "showphoto. aspx"> </ASP: Image> showphoto. aspx subject code:
Private void page_load (Object sender, system. eventargs E)
{
If (! Page. ispostback)
{
Sqlconnection conn = new sqlconnection ()
Conn. connectionstring = "Data Source = localhost; database = test; user id = sa; Pwd = sa"; string strsql = "select * from test where id = 2 "; // assume that the image with ID 2 is obtained.
Sqlcommand cmd = new sqlcommand (strsql, Conn); Conn. open ();
Sqldatareader reader = cmd. executereader ();
Reader. Read (); response. contenttype = "application/octet-stream ";
Response. binarywrite (byte []) Reader ["fimage"]);
Response. End ();
Reader. Close ();
}
} 2. Save the image to SQL Server in winform, read it from SQL Server, and display it in picturebox. 1) Save it to SQL Server
The database structure and stored procedures used are the same as above.
First, add an openfiledialog control in the form and name it ofdselectpic;
Then, add an open file button on the form and add the following Event code:
Stream MS;
Byte [] picbyte;
// Ofdselectpic. showdialog ();
If (ofdselectpic. showdialog () = dialogresult. OK)
{
If (MS = ofdselectpic. openfile ())! = NULL)
{
// MessageBox. Show ("OK ");
Picbyte = new byte [Ms. Length];
Ms. Position = 0;
Ms. Read (picbyte, 0, convert. toint32 (Ms. Length ));
// MessageBox. Show ("read finished! "); // Connect to the database
Sqlconnection conn = new sqlconnection ();
Conn. connectionstring = "Data Source = localhost; database = test; user id = sa; Pwd = sa"; sqlcommand cmd = new sqlcommand ("updateimage", Conn );
Cmd. commandtype = commandtype. storedprocedure; cmd. Parameters. Add ("@ updateimage", sqldbtype. Image );
Cmd. Parameters ["@ updateimage"]. value = picbyte; Conn. open ();
Cmd. executenonquery ();
Conn. Close (); Ms. Close ();
}
} 2) read and display in picturebox
First, add a picturebox named ptbshow
Then, add a button to add the following response event:
Sqlconnection conn = new sqlconnection ();
Conn. connectionstring = "Data Source = localhost; database = test; user id = sa; Pwd = sa"; string strsql = "select fimage from test where id = 1 "; sqlcommand cmd = new sqlcommand (strsql, Conn); Conn. open ();
Sqldatareader reader = cmd. executereader ();
Reader. read (); memorystream MS = new memorystream (byte []) Reader ["fimage"]); image = image. fromstream (MS, true); reader. close ();
Conn. Close (); ptbshow. Image = image;