使用ASP.NET C＃中的gridview从文件夹和数据库中删除图像 [英] Delete image from folder and database using gridview in ASP.NET C#

问题描述

我可以从数据库中删除，但我不知道如何从文件夹中删除图片。

请帮助。

为了更好地理解，请编辑我的代码并粘贴。

提前致谢。



我尝试过：

 protected void Button1_Click（object sender，EventArgs e）
 {
 SqlCommand command = new SqlCommand（SPinsertitem，con）; 
 command.CommandType = CommandType.StoredProcedure; 
 //上传图片1 // 
 string strname = picture1.FileName.ToString（）; 
 strname =〜//品牌//新文件夹//+ strname; 
 picture1.PostedFile.SaveAs（Server.MapPath（strname））; 
 command.Parameters.Add（@ imageone，SqlDbType.VarChar，100）.Value = strname; 
 // UPLOAD IMAGE 2 // 
 string strname2 = picture2.FileName.ToString（）; 
 strname2 =〜//品牌//新文件夹//+ strname2; 
 picture2.PostedFile.SaveAs（Server.MapPath（strname2））; 
 command.Parameters.Add（@ imagetwo，SqlDbType.VarChar，100）.Value = strname2; 
 //上传图片3 // 
 string strname3 = picture3.FileName.ToString（）; 
 strname3 =〜//品牌//新文件夹//+ strname3; 
 picture3.PostedFile.SaveAs（Server.MapPath（strname3））; 
 command.Parameters.Add（@ imagethree，SqlDbType.VarChar，100）.Value = strname3; 

 protected void BindGrid （）
 {
 
 SqlDataAdapter myCommand = new SqlDataAdapter（SELECT * FROM pikiphones，con）; 
 DataSet ds = new DataSet（）; 
 myCommand.Fill（ds）; 
 GridView1.DataSource = ds; 
 GridView1.DataBind（）; 
} 

 protected void delete_rOW（object sender，GridViewDeleteEventArgs e）
 {
 String deleteCmd =DELETE来自pikiphones WHERE id = @id; 
 SqlCommand myCommand = new SqlCommand（deleteCmd，con）; 
 myCommand.Parameters.Add（new SqlParameter（@ id，SqlDbType.Int））; 
 myCommand.Parameters [@ id]。Value = Convert.ToInt32（GridView1.Rows [e.RowIndex] .Cells [1] .Text）; 
 try 
 {
 myCommand.ExecuteNonQuery（）; 
} 
 catch（SqlException）
 {
 Label1.Text =错误：无法删除记录; 
 
} 
 myCommand.Connection.Close（）; 
 
 BindGrid（）; 
} 

解决方案

我看不到你试图删除文件的地方。



你可以使用 Systme.IO.File.Delete（path）; ，但无论如何都不需要将文件保存到文件系统：



将图像字段设置为varbinary（最大值）：

 创建 表图像（
 image_id  int  不  null   identity （  1 ， 1 ） primary   key ，
 image_image1_name  nvarchar （max），
 image_image1_binary  varbinary （max）
   -    ...  
）
 

然后直接从上传中读取文件流。无需保存，只需将其作为byte []保存在内存中几个周期。

  //   ....  
  byte  [ ] input =  new   byte  [picture1.ContentLength]; 
 
  var  stream = picture1.InputStream; 
 
 stream.Read（输入， 0 ，picture1.ContentLength）; 
 
 command.Parameters.Add（  @ image1Name，SqlDbType.VarChar ， 100 ）。Value = picture1.FileName; 
 command.Parameters.Add（  @ image1Byte，SqlDbType.VarBinary，file.Length ）.Value =输入; 

这就是我在整个地方上传文件的方式。清理起来要快得多，也不那么麻烦，因为当你完成它时GC会把文件分开。



我希望有帮助^ _ ^

最后解决方案的附录：



好​​的 - 首先你需要尝试删除该项目，最好在参考之前，但它没有无所谓。只需确保在删除条目之前获得路径：

  protected   void  delete_rOW（ object  sender，GridViewDeleteEventArgs e）
 {
 
 
  //  我会写这个最佳实践 
 
  var  id = Convert.ToInt32（GridView1.Rows [e.RowIndex] .Cells [ 1 ] .Text）
  string  selectCmd =  选择来自pikiphones的路径WHERE id = @id 
 使用（SqlCommand com = con.CreateCommand）{
 com.Text = selectCmd ; 
 com.Parameters.Add（ new  SqlParameter（  @id，SqlDbType.Int）{Value = id}）; 
  var  path = com.ExecuteScalar（）。toString（）; 
 
  if （！string.isNullOrEmpty（path）&& Path.Exists（path））{
  //   try catch？ 
 Path.Delete（path）; 
} 
} 
 
 
 字符串 deleteCmd =    DELETE FROM pikiphones WHERE id = @id; 
 SqlCommand myCommand =  new  SqlCommand（deleteCmd，con）; 
 myCommand.Parameters.Add（ new  SqlParameter（  @id，SqlDbType.Int））; 
 myCommand.Parameters [  @ id]。Value = id; 
 尝试 
 {
 myCommand.ExecuteNonQuery（）; 
} 
  catch （SqlException）
 {
 Label1.Text =   错误：无法删除记录; 
 
} 
 myCommand.Connection.Close（）; 
 
 BindGrid（）; 
} 

您可能需要调试它。我知道我有一些方法关键字错了。如果你遇到困难，请告诉我^ _ ^

I am able to delete from database but i do not know how delete image from folder.
Please help .
for better understanding please edit my code and paste.
Thanks in advance.

What I have tried:

protected void Button1_Click(object sender, EventArgs e)
    {
        SqlCommand command = new SqlCommand("SPinsertitem", con);
        command.CommandType = CommandType.StoredProcedure;
// UPLOAD IMAGE 1 //
        string strname = picture1.FileName.ToString();
        strname = "~//brand//New folder//" + strname;
        picture1.PostedFile.SaveAs(Server.MapPath(strname));
        command.Parameters.Add("@imageone", SqlDbType.VarChar, 100).Value = strname;
        // UPLOAD IMAGE 2 //
        string strname2 = picture2.FileName.ToString();
        strname2 = "~//brand//New folder//" + strname2;
        picture2.PostedFile.SaveAs(Server.MapPath(strname2));
        command.Parameters.Add("@imagetwo", SqlDbType.VarChar, 100).Value = strname2;
        // UPLOAD IMAGE 3 // 
        string strname3 = picture3.FileName.ToString();
        strname3 = "~//brand//New folder//" + strname3;
        picture3.PostedFile.SaveAs(Server.MapPath(strname3));
        command.Parameters.Add("@imagethree", SqlDbType.VarChar, 100).Value = strname3;

protected void BindGrid()
    {

        SqlDataAdapter myCommand = new SqlDataAdapter("SELECT * FROM pikiphones", con);
        DataSet ds = new DataSet();
        myCommand.Fill(ds);
        GridView1.DataSource = ds;
        GridView1.DataBind();
    }

protected void delete_rOW(object sender, GridViewDeleteEventArgs e)
    {
        String deleteCmd = "DELETE FROM pikiphones WHERE id= @id";
        SqlCommand myCommand = new SqlCommand(deleteCmd, con);
        myCommand.Parameters.Add(new SqlParameter("@id", SqlDbType.Int));
        myCommand.Parameters["@id"].Value = Convert.ToInt32(GridView1.Rows[e.RowIndex].Cells[1].Text);
        try
        {
            myCommand.ExecuteNonQuery();
        }
        catch (SqlException)
        {
            Label1.Text = "ERROR: Could not delete record";

        }
        myCommand.Connection.Close();
        
        BindGrid();
    }

解决方案

I see nowhere where you try to delete the file.

You can just use Systme.IO.File.Delete(path);, but there is no need to save the file to the file system anyway:

set up the image field as a varbinary(max):

Create Table images(
  image_id int not null identity(1,1) primary key,
  image_image1_name nvarchar(max),
  image_image1_binary varbinary(max)
-- ...
)

Then read the file stream directly from the upload. No need to save it, just keep it in memory as a byte[] for a couple of cycles.

//....
    byte[] input = new byte[picture1.ContentLength];

    var stream = picture1.InputStream;

    stream.Read(input, 0, picture1.ContentLength);
    
    command.Parameters.Add("@image1Name", SqlDbType.VarChar, 100).Value=picture1.FileName;
    command.Parameters.Add("@image1Byte", SqlDbType.VarBinary, file.Length).Value=input;

This is how I upload files all over the place. It's much faster and less hastle to clean up as the GC will bin the file when you're finished with it.

I hope that helps ^_^

Addendum to last solution:

Ok - first you need to try to delete the item, preferably before the reference, but it doesn't matter. Just make sure you get the path before deleting the entry:

protected void delete_rOW(object sender, GridViewDeleteEventArgs e)
    {


        //I'll write this "best practice"

        var id = Convert.ToInt32(GridView1.Rows[e.RowIndex].Cells[1].Text) 
        string selectCmd = "select path from pikiphones WHERE id= @id"
        using(SqlCommand com = con.CreateCommand){
            com.Text = selectCmd;
            com.Parameters.Add(new SqlParameter("@id", SqlDbType.Int){Value=id});
            var path = com.ExecuteScalar().toString();

            if(!string.isNullOrEmpty(path) && Path.Exists(path)){
               //try catch?
               Path.Delete(path);
            }
        }


        String deleteCmd = "DELETE FROM pikiphones WHERE id= @id";
        SqlCommand myCommand = new SqlCommand(deleteCmd, con);
        myCommand.Parameters.Add(new SqlParameter("@id", SqlDbType.Int));
        myCommand.Parameters["@id"].Value = id;
        try
        {
            myCommand.ExecuteNonQuery();
        }
        catch (SqlException)
        {
            Label1.Text = "ERROR: Could not delete record";

        }
        myCommand.Connection.Close();
        
        BindGrid();
    }

You may have to debug it. I know I have some method keywords wrong. Let me know if you get stuck ^_^

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