我想显示存储在数据库中的图像 [英] I want to display image that stored in database

问题描述

这是我的数据库：

This is my database:

create table images 
(
     ID int primary key identity, 
     Name nvarchar(255),
     Size int, 
     ImgData varbinary(max) 
)

CREATE PROCEDURE UploadImages
     @Name nvarchar(255),
     @Size int,
     @ImgData varbinary(max),
     @NewId int output
AS
BEGIN
    INSERT INTO images
    VALUES (@Name, @Size, @ImgData)

    SELECT @NewId = SCOPE_IDENTITY()    
END

这是我的代码：

This is my code:

HttpPostedFile PostedFile = FileUpload1.PostedFile;

 string fileName = Path.GetFileName(PostedFile.FileName);
 string fileExtension = Path.GetExtension(fileName);
 int fileSize = PostedFile.ContentLength;

 if(fileExtension.ToLower() == ".jpg" || fileExtension.ToLower() == ".bmp"|| fileExtension.ToLower() == ".gif" || fileExtension.ToLower() == ".png")
 {
     Stream stream = PostedFile.InputStream;
     BinaryReader binaryReader = new BinaryReader(stream);

     byte[] bytes = binaryReader.ReadBytes((int)stream.Length);

     string cs = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;

     using (SqlConnection con = new SqlConnection(cs))
     {
         SqlCommand cmd = new SqlCommand("UploadImages", con);
         cmd.CommandType = CommandType.StoredProcedure;

         con.Open();

         SqlParameter paramName = new SqlParameter()
         {
             ParameterName = "@Name",
             Value = fileName
         };
         cmd.Parameters.Add(paramName);

         SqlParameter paramSize = new SqlParameter()
         {
             ParameterName = "@Size",
             Value = fileSize
         };
         cmd.Parameters.Add(paramSize);

         SqlParameter paramImgData = new SqlParameter()
         {
             ParameterName = "@ImgData",
             Value = bytes
         };
         cmd.Parameters.Add(paramImgData);

         SqlParameter paramNewId = new SqlParameter()
         {
             ParameterName = "@NewId",
             Value =-1,
             Direction = ParameterDirection.Output
         };
         cmd.Parameters.Add(paramNewId);

         cmd.ExecuteNonQuery();
         con.Close();

         Lmas.Visible = true;
         Lmas.Text = "done";
         Lmas.ForeColor = System.Drawing.Color.Green;
         HyperLink1.Visible = true;
         HyperLink1.NavigateUrl = "~/ShowImage.aspx?Id=" + cmd.Parameters["@NewId"].Value.ToString();

         //LoadImage();
     } 
 } 
 else 
 {
     Lmas.Visible = true;
     Lmas.Text = "only images (.jpg .png .gif .bmp) can be uploaded";
     Lmas.ForeColor = System.Drawing.Color.Red;
     HyperLink1.Visible = false;
 }

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



我尝试过：



我试图在第一页的img-tag或label中显示我的图像相同的页面，但它不起作用，我试过这个代码，但不工作：

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

What I have tried:

I tried to display my image in img-tag or label in first page not in the same page but it does not work , I tried this code but not work:

string cs = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;
        using (SqlConnection con = new SqlConnection(cs))
        {
            SqlCommand cmd = new SqlCommand("spGetImageById", con);
            cmd.CommandType = CommandType.StoredProcedure;

            SqlParameter paramID = new SqlParameter()
            {
                ParameterName = "@ID",
                Value = Request.QueryString["ID"]
            };
            cmd.Parameters.Add(paramID);

            con.Open();
            cmd.ExecuteScalar();
            byte[] bytes = (byte[])cmd.ExecuteScalar();
            string strBase64 = Convert.ToBase64String(bytes);
            Image1.ImageUrl = "data:Image/png;base64," + strBase64;

推荐答案

看一下表定义：

Take a look at table definition:

create table images 
(
     ID int primary key identity, --required!
     Name nvarchar(255),
     Size int, 
     ImgData varbinary(max) 
)

和SP中的INSERT语句：

and your INSERT statement in SP:

INSERT INTO images
VALUES (@Name, @Size, @ImgData)

你错过了什么？ ID ！



根据具体情况，您必须：

What you miss? ID!

Depending on situation, you have to:

1. 将 ID 字段定义更改为
   
   

1. change ID field definition to
   

ID int primary key identity(1,1)

提供自动增量。然后你就可以忽略 ID 。

to provide autoincrement. Then you'll be able to ignore ID.

INSERT INTO images (Name, Size, ImgData)
VALUES (@Name, @Size, @ImgData)

或

将SP中的插入声明更改为：

or

change insert statement in your SP to:

INSERT INTO images (ID, Name, Size, ImgData)
VALUES (@ID, @Name, @Size, @ImgData)

注意，C＃代码应相应更改！

有关详细信息，请参阅过去的答案：
如何将图像插入MS Access [ ^ ]

在访问数据库中插入图像 [ ^ ]

For further details, please see past answers:
How will I insert an image to MS Access[^]
insert image in access database[^]

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