从列表框和数据源c#中删除项目

本文关键字：删除项目 数据源 列表 | 更新日期: 2023-09-27 17:58:19

我试图从列表框和数据表中删除一个项目，但我很难做到。我现在可以从列表框中删除它，但我不知道如何从表中删除它。

这是我的代码

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        //if this is the first time th page is displayed
        if (IsPostBack == false)
        {
            //update the list box
            DisplayToDoList();
        }
    }
//this function populates the list box with to do list items
//it returns the number of records in the list
Int32 DisplayToDoList()
{
    //var to store the record count
    Int32 RecordCount;
    //create an instance of the todo class
    clsToDoList MyList = new clsToDoList();
    //get the count of records
    RecordCount = MyList.Count;
    //var to store the index
    Int32 Index = 0;
    //var to store the primary key
    Int32 ToDoNo;
    //var to store the to do text
    String ToDo;
    //clear the list
    lstToDo.Items.Clear();
    //loop through each record
    while (Index < RecordCount)
    {
        //get the primary key
        ToDoNo = MyList.List[Index].ToDoNo;
        //get the text
        ToDo = MyList.List[Index].ToDo;
        //create a new entry for the list
        ListItem NewEntry = new ListItem(ToDo, Convert.ToString(ToDoNo));
        //add the entry to the list box
        lstToDo.Items.Add(NewEntry);
        //increment the indez
        Index++;
    }
    //return the number of records 
    return RecordCount;
}
protected void btnAdd_Click(object sender, EventArgs e)
{
//add value from textbox to listbox
lstToDo.Items.Add(txtToDo.Text);
}

protected void btnDelete_Click(object sender, EventArgs e)
{
    if (this.lstToDo.SelectedIndex >= 0)
        this.lstToDo.Items.RemoveAt(this.lstToDo.SelectedIndex);
}

clsToDoList 的代码

公共类clsToDoList{公用Int32计数{收到{Int32 RecordCount；clsDataConnection MyConnection=新的clsDataConnection[（）；MyConnection.Execute（"sproc_tblToDo_SelectAll"）；RecordCount=MyConnection.Count；return RecordCount；

    }

    }

public List<clsToDoItem>List
{
    get
    {
        List<clsToDoItem> NewList = new List<clsToDoItem>();
        Int32 RecordCount;
        Int32 Index = 0;
        clsDataConnection MyConnection = new clsDataConnection();
        MyConnection.Execute("sproc_tblToDo_SelectAll");
        RecordCount = MyConnection.Count;
        while (Index < RecordCount)
        {
            clsToDoItem BlankPage = new clsToDoItem();
            BlankPage.ToDoNo = Convert.ToInt32(MyConnection.DataTable.Rows[Index]["ToDoNo"]);
            BlankPage.ToDo = Convert.ToString(MyConnection.DataTable.Rows[Index]["ToDo"]);
            NewList.Add(BlankPage);
            Index++;
        }
        return NewList;
    }

    }
}

从列表框和数据源c#中删除项目

创建一个变量，并将值设置为等于所选项目的值。

string _itemToDelete
protected void btnDelete_Click(object sender, EventArgs e)
{
if (this.lstToDo.SelectedIndex >= 0)
{  
   _itemToDelete = this.1stToDo.items.SelectedIndex.ToString() // or text cant remember
   this.lstToDo.Items.RemoveAt(this.lstToDo.SelectedIndex);
   connect to SQL Table       
   "DELETE FROM table WHERE column_name LIKE" + "_itemToDelete"
}
}

类似这样的东西：

public static void Delete(int ID)
{
using (SqlConnection conn = new SqlConnection())
{
        conn.connectionString = "";
conn.open();    
sqlcommand sc = new sqlcommand();
        sc.connection = conn;
        sc.commandText = "DELETE FROM TABLE WHERE ID = @ID";
        sc.Parameters.AddWithValue("@ID", ID);

        sc.ExecuteNonQuery();
        conn.close()
}
}

ViewModel:

    public MyList Items { get; private set; }
    public ICommand Delete { get; private set; }
private void delete(object sender)
{
 var item = sender as ItemType;
 if (item == null)
   return;
  MyList.RemoveOnSubmit(item);
  YourDataContextSQL.SubmitChanges();
}

视图：

    <ListBox ItemsSource="{Binding Items}">
        <ListBox.ItemTemplate>
            <DataTemplate>
                <Button Content="Delete"
                        Command="{Binding Delete}"
                        CommandParameter="{Binding}"/>
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>
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