如何将图像放入选定位置并存储在数据库中

Question

我有一个页面，用于上传图像并将其路径保存到数据库中，并具有图像的优先级。 现在这只是一个例子，我的数据库中有 5 张图像，它们的优先级如下：

ID  ImageName  Description  Path  Priority
 1    1.jpg      Hello      xxxx   1
 2    2.jpg       hi        xxxx   2
 3    3.jpg       how       xxxx   3
 4    4.jpg       good      xxxx   4
 5    5.jpg       bye       xxxx   5

在我的页面中，我有 File-Uploader 控件来上传文件和下拉列表的优先级，其中优先级来自数据库。

现在我的问题是当我浏览要上传的图片并从下拉列表中选择优先级时 图像应置于该优先级，该图像的优先级增加 1，依此类推

如果我想上传 6 号图像并将其存储在 3 优先级，那么数据库应该是这样的

ID  ImageName  Description  Path  Priority
 1    1.jpg      Hello      xxxx   1
 2    2.jpg       hi        xxxx   2
 6    6.jpg       you       xxxx   3
 3    3.jpg       how       xxxx   4
 4    4.jpg       good      xxxx   5
 5    5.jpg       bye       xxxx   6

这是我上传 image.aspx.cs 文件的代码

protected void Page_Load(object sender, EventArgs e)
{
    AutoNumber(); 
}
public void AutoNumber()
{     
    con.Open();
    SqlCommand cmd = new SqlCommand("SELECT COUNT(Priority) as Tot FROM TestImages", con);
    SqlDataReader dr;

    dr = cmd.ExecuteReader();
    while (dr.Read())
    {
        int i = Convert.ToInt32(dr["tot"]);

        if (i > 0)
        {
            int j = i + 1;
            lblPriority.Text = "0" + j.ToString();

        }
        else
        {
            lblPriority.Text = "1";
        }

    }
    con.Close();
}
protected void btnSubmit_Click1(object sender, EventArgs e)
{
    con.ConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings["WebGallery"].ConnectionString;
    string Priority = lblPriority.Text.Trim();
    //Get Filename from fileupload control
    string imgName = fileuploadimages.FileName.ToString();
    //sets the image path
    string imgPath = "Images/"+""+ddlDepartment.SelectedValue+"/";
    bool IsExists = System.IO.Directory.Exists(Server.MapPath(imgPath));
    if (!IsExists)
        System.IO.Directory.CreateDirectory(Server.MapPath(imgPath));        
    //then save it to the Folder
    fileuploadimages.SaveAs(Server.MapPath(imgPath+imgName));
    //Open the database connection
    con.Open();
    //Query to insert images name and Description into database
    SqlCommand cmd = new SqlCommand("Insert into TestImages(ImageName,Description,Path,Priority) values(@ImageName,@Description,@Path,@Priority)" + "Update TestImages set Priority=Priority+1 where Priority='" + ddlPriority.SelectedValue + "'", con);
    //Passing parameters to query
    cmd.Parameters.AddWithValue("@ImageName", imgName);
    cmd.Parameters.AddWithValue("@Description", tbImageName.Text);
    cmd.Parameters.AddWithValue("@Path", imgPath + imgName);
    cmd.Parameters.AddWithValue("@Priority", lblPriority.Text);
    cmd.ExecuteNonQuery();
    //Close dbconnection
    con.Close();
    tbImageName.Text = string.Empty;     
}   
}

它更新和插入都没有错误，但它不会从下拉列表中选择的优先级插入，它将在最后添加并更新优先级。

如何从选定的优先级放置图像 提前致谢

Answer 1

您必须更新数据库中的每一行。试试这样的：

Image newImage;        //Your image uploaded
List<Image> listImages; //All the images from your DB (before insertion)

foreach(Image img in listImages) {
   if(img['Priority'] < newImg['Priority']) 
   {
      SqlCommand cmd = new SqlCommand(
                  "UPDATE TestImage SET Priority=" + img['Priority'] - 1 + ";"); 
   }
   else
   {
      SqlCommand cmd = new SqlCommand(
                  "UPDATE TestImage SET Priority=" + img['Priority'] + 1 + ";"); 

   }

}

Answer 2

我终于得到了答案

 protected void ChangePriority_Click(object sender, EventArgs e)
{
    //con.ConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings["WebGallery"].ConnectionString;
    string DepartmentID = ddlDepartment.SelectedValue;
    string Description = tbImageName.Text.Trim();
    //string Priority = lblPriority.Text.Trim();
    string Priority = ddlPriority.SelectedValue;
    //Get Filename from fileupload control
    string imgName = fileuploadimages.FileName.ToString();
    //sets the image path if exist then store image in that place else create one
    string imgPath = "Images/Departments/" + "" + ddlDepartment.SelectedValue + "/";
    bool IsExists = System.IO.Directory.Exists(Server.MapPath(imgPath));
    if (!IsExists)
        System.IO.Directory.CreateDirectory(Server.MapPath(imgPath));
    //then save it to the Folder
    fileuploadimages.SaveAs(Server.MapPath(imgPath + imgName));
    //Open the database connection
    con.Open();
    //Query to insert * into images into database

    SqlCommand cmd = new SqlCommand("Update Images set Priority=Priority+1 where Priority>='" + ddlPriority.SelectedValue + "'" + "Insert into Images(ImageName,Description,Path,Priority,DepartmentID) values(@ImageName,@Description,@Path,@Priority,@DepartmentID)", con);
    //Passing parameters to query
    cmd.Parameters.AddWithValue("@ImageName", imgName);
    cmd.Parameters.AddWithValue("@Description", Description);
    cmd.Parameters.AddWithValue("@Path", imgPath + imgName);
    cmd.Parameters.AddWithValue("@Priority", Priority);
    cmd.Parameters.AddWithValue("@DepartmentID", DepartmentID);
    cmd.ExecuteNonQuery();
    //Close dbconnection
    con.Close();
    tbImageName.Text = string.Empty;
   // Response.Redirect(Request.RawUrl);
}