DataGrid.Items DataGrid.Items DataGrid.Items DataGrid.Items Property

Definizione

Ottiene un insieme di oggetti DataGridItem che rappresentano i singoli elementi nel controllo DataGrid.Gets a collection of DataGridItem objects that represent the individual items in the DataGrid control.

public:
 virtual property System::Web::UI::WebControls::DataGridItemCollection ^ Items { System::Web::UI::WebControls::DataGridItemCollection ^ get(); };
[System.ComponentModel.Browsable(false)]
public virtual System.Web.UI.WebControls.DataGridItemCollection Items { get; }
member this.Items : System.Web.UI.WebControls.DataGridItemCollection
Public Overridable ReadOnly Property Items As DataGridItemCollection

Valore della proprietà

Un oggetto DataGridItemCollection contenente un insieme di oggetti DataGridItem che rappresentano i singoli elementi nel controllo DataGrid.A DataGridItemCollection that contains a collection of DataGridItem objects representing the individual items in the DataGrid control.

Esempi

Il codice seguente viene illustrato come utilizzare il Items per visualizzare il contenuto di ogni elemento nella raccolta di DataGrid controllo.The following code example demonstrates how to use the Items collection to display the contents of each item in the DataGrid control.

<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<script language="C#" runat="server">
 
   DataTable Cart;
   DataView CartView;
 
   ICollection CreateDataSource() 
   {
      DataTable dt = new DataTable();
      DataRow dr;
 
      dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
      dt.Columns.Add(new DataColumn("StringValue", typeof(string)));
      dt.Columns.Add(new DataColumn("CurrencyValue", typeof(double)));
 
      for (int i = 0; i < 10; i++) 
      {
         dr = dt.NewRow();
 
         dr[0] = i;
         dr[1] = "Item " + i.ToString();
         dr[2] = 1.23 * (i+1);
 
         dt.Rows.Add(dr);
      }
 
      DataView dv = new DataView(dt);
      return dv;
   }
 
   void Page_Load(Object sender, EventArgs e) 
   {
 
      if (!IsPostBack) 
      {
         // Need to load this data only once.
         ItemsGrid.DataSource = CreateDataSource();
         ItemsGrid.DataBind();
      }
 
   }
 
   void Button_Click(Object sender, EventArgs e) 
   {
 
      foreach (DataGridItem item in ItemsGrid.Items)
      { 
         Label1.Text += "<br />" + item.Cells[0].Text + 
                        " " + item.Cells[1].Text + 
                        " " + item.Cells[2].Text;
      }
 
   }
 
</script>
 
<head runat="server">
    <title>DataGrid Items Collection Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

      <h3>DataGrid Items Collection Example</h3>
 
      <asp:DataGrid id="ItemsGrid" runat="server"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           ShowFooter="true"
           AutoGenerateColumns="true">

         <HeaderStyle BackColor="#00aaaa">
         </HeaderStyle>

         <FooterStyle BackColor="#00aaaa">
         </FooterStyle>
   
      </asp:DataGrid>
 
      <br />

      <asp:Button id="Button1"
           Text="Display Contents of Items Collection"
           OnClick="Button_Click"
           runat="server"/>

      <br />
 
      <asp:Label id="Label1" 
           runat="server"/>
 
   </form>
 
</body>
</html>

<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<script language="VB" runat="server">
 
    Dim Cart As DataTable
    Dim CartView As DataView
    
    Function CreateDataSource() As ICollection
        Dim dt As New DataTable()
        Dim dr As DataRow
        
        dt.Columns.Add(New DataColumn("IntegerValue", GetType(Int32)))
        dt.Columns.Add(New DataColumn("StringValue", GetType(String)))
        dt.Columns.Add(New DataColumn("CurrencyValue", GetType(Double)))
        
        Dim i As Integer
        For i = 0 To 9
            dr = dt.NewRow()
            
            dr(0) = i
            dr(1) = "Item " & i.ToString()
            dr(2) = 1.23 *(i + 1)
            
            dt.Rows.Add(dr)
        Next i
        
        Dim dv As New DataView(dt)
        Return dv
    End Function 'CreateDataSource


    Sub Page_Load(sender As Object, e As EventArgs)
        
        If Not IsPostBack Then
            ' Need to load this data only once.
            ItemsGrid.DataSource = CreateDataSource()
            ItemsGrid.DataBind()
        End If
    End Sub 'Page_Load
     

    Sub Button_Click(sender As Object, e As EventArgs)
        
        Dim item As DataGridItem
        For Each item In  ItemsGrid.Items
            Label1.Text &= "<br />" & item.Cells(0).Text & _
                        " " & item.Cells(1).Text & _
                        " " & item.Cells(2).Text
        Next item
    End Sub 'Button_Click
 
</script>
 
<head runat="server">
    <title>DataGrid Items Collection Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

      <h3>DataGrid Items Collection Example</h3>
 
      <asp:DataGrid id="ItemsGrid" runat="server"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           ShowFooter="true"
           AutoGenerateColumns="true">

         <HeaderStyle BackColor="#00aaaa">
         </HeaderStyle>

         <FooterStyle BackColor="#00aaaa">
         </FooterStyle>
   
      </asp:DataGrid>
 
      <br />

      <asp:Button id="Button1"
           Text="Display Contents of Items Collection"
           OnClick="Button_Click"
           runat="server"/>

      <br />
 
      <asp:Label id="Label1" 
           runat="server"/>
 
   </form>
 
</body>
</html>


<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
   <script runat="server">
 
      ICollection CreateDataSource() 
      {
      
         // Create sample data for the DataGrid control.
         DataTable dt = new DataTable();
         DataRow dr;
 
         // Define the columns of the table.
         dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
         dt.Columns.Add(new DataColumn("StringValue", typeof(string)));
         dt.Columns.Add(new DataColumn("CurrencyValue", typeof(double)));
 
         // Populate the table with sample values.
         for (int i = 0; i < 5; i++) 
         {
            dr = dt.NewRow();
 
            dr[0] = i;
            dr[1] = "Item " + i.ToString();
            dr[2] = 1.23 * (i + 1);
 
            dt.Rows.Add(dr);
         }
 
         DataView dv = new DataView(dt);
         return dv;
      }
 
      void Page_Load(Object sender, EventArgs e) 
      {
 
         // Load sample data only once, when the page is first loaded.
         if (!IsPostBack) 
         {
            ItemsGrid.DataSource = CreateDataSource();
            ItemsGrid.DataBind();
         }

      }

      void Button_Click(Object sender, EventArgs e) 
      {

         // Count the number of selected items in the DataGrid control.
         int count = 0;

         // Display the selected times.
         Message.Text = "You Selected: <br />";

         // Iterate through each item (row) in the DataGrid control and
         // determine whether it is selected.
         foreach (DataGridItem item in ItemsGrid.Items)
         {

            DetermineSelection(item, ref count);        

         }

         // If no items are selected, display the appropriate message.
         if (count == 0)
         {

            Message.Text = "No items selected";

         }

      }

      void DetermineSelection(DataGridItem item, ref int count)
      {

         // Retrieve the SelectCheckBox CheckBox control from the 
         // specified item (row) in the DataGrid control.
         CheckBox selection = (CheckBox)item.FindControl("SelectCheckBox");

         // If the item is selected, display the appropriate message and
         // increment the count of selected items.
         if (selection != null)
         {

           if (selection.Checked)
           {
              Message.Text += "- " + item.Cells[1].Text + "<br />";
              count++;
           }

         }    

      }

      void Check_Change(Object sender, EventArgs e)
      {

         // Show or hide the first column depending on the value of
         // the check box.
         if (ShowCheckBox.Checked)
         {
            ItemsGrid.Columns[0].Visible = true;
         }
         else
         {
            ItemsGrid.Columns[0].Visible = false;
         }

      }

   </script>
 
<head runat="server">
    <title>DataGridColumn Visible Example</title>
</head>
<body>
 
   <form id="form1" runat="server">
 
      <h3>DataGridColumn Visible Example</h3>

      Select whether to show or hide the first column.

      <br /><br />
 
      <b>Product List</b>
 
      <asp:DataGrid id="ItemsGrid"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           ShowFooter="True"
           AutoGenerateColumns="False"
           runat="server">

         <HeaderStyle BackColor="#00aaaa">
         </HeaderStyle>

         <FooterStyle BackColor="#00aaaa">
         </FooterStyle>

         <Columns>

            <asp:BoundColumn DataField="IntegerValue"
                 Visible="True" 
                 HeaderText="Item"/>

            <asp:BoundColumn DataField="StringValue"
                 Visible="True"  
                 HeaderText="Description"/>

            <asp:BoundColumn DataField="CurrencyValue"
                 Visible="True"  
                 HeaderText="Price"
                 DataFormatString="{0:c}">

               <ItemStyle HorizontalAlign="Right">
               </ItemStyle>

            </asp:BoundColumn>

            <asp:TemplateColumn HeaderText="Select Item"
                 Visible="True" >

               <ItemTemplate>

                  <asp:CheckBox id="SelectCheckBox"
                       Text="Add to Cart"
                       Checked="False"
                       runat="server"/>

               </ItemTemplate>

            </asp:TemplateColumn>
 
         </Columns>  
 
      </asp:DataGrid>

      <br /><br />

      <asp:Button id="SubmitButton"
           Text="Submit"
           OnClick = "Button_Click"
           runat="server"/>

      <br /><br />

      <asp:Label id="Message"
           runat="server"/>

      <hr />

      <asp:CheckBox id="ShowCheckBox"
           Text="Show first column"
           AutoPostBack="True"
           OnCheckedChanged="Check_Change"
           Checked="True"
           runat="server"/>
 
   </form>
 
</body>
</html>


<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
   <script runat="server">
 
      Function CreateDataSource() As ICollection 
      
         ' Create sample data for the DataGrid control.
         Dim dt As DataTable = New DataTable()
         Dim dr As DataRow
 
         ' Define the columns of the table.
         dt.Columns.Add(New DataColumn("IntegerValue", GetType(Int32)))
         dt.Columns.Add(New DataColumn("StringValue", GetType(string)))
         dt.Columns.Add(New DataColumn("CurrencyValue", GetType(double)))
 
         ' Populate the table with sample values.
         Dim i As Integer

         For i = 0 to 4 
        
            dr = dt.NewRow()
 
            dr(0) = i
            dr(1) = "Item " & i.ToString()
            dr(2) = 1.23 * (i + 1)
 
            dt.Rows.Add(dr)

         Next i
 
         Dim dv As DataView = New DataView(dt)
         Return dv

      End Function
 
      Sub Page_Load(sender As Object, e As EventArgs) 
 
         ' Load sample data only once, when the page is first loaded.
         If Not IsPostBack Then 
  
            ItemsGrid.DataSource = CreateDataSource()
            ItemsGrid.DataBind()

         End If

      End Sub

      Sub Button_Click(sender As Object, e As EventArgs) 

         ' Count the number of selected items in the DataGrid control.
         Dim count As Integer = 0

         ' Display the selected times.
         Message.Text = "You Selected: <br />"

         ' Iterate through each item (row) in the DataGrid control and
         ' determine whether it is selected.
         Dim item As DataGridItem
 
         For Each item In ItemsGrid.Items

            DetermineSelection(item, count)        

         Next

         ' If no items are selected, display the appropriate message.
         If count = 0 Then

            Message.Text = "No items selected"

         End If

      End Sub

      Sub DetermineSelection(item As DataGridItem, ByRef count As Integer)

         ' Retrieve the SelectCheckBox CheckBox control from the 
         ' specified item (row) in the DataGrid control.
         Dim selection As CheckBox = _
             CType(item.FindControl("SelectCheckBox"), CheckBox)

         ' If the item is selected, display the appropriate message and
         ' increment the count of selected items.
         If Not selection Is Nothing Then

           If selection.Checked Then
           
              Message.Text &= "- " & item.Cells(1).Text & "<br />"
              count = count + 1
           
           End If

         End If    

      End Sub

      Sub Check_Change(sender As Object, e As EventArgs)

         ' Show or hide the first column depending on the value of
         ' the check box.
         If ShowCheckBox.Checked Then
        
            ItemsGrid.Columns(0).Visible = True
         
         Else
         
            ItemsGrid.Columns(0).Visible = False
         
         End If

      End Sub

   </script>
 
<head runat="server">
    <title>DataGridColumn Visible Example</title>
</head>
<body>
 
   <form id="form1" runat="server">
 
      <h3>DataGridColumn Visible Example</h3>

      Select whether to show or hide the first column.

      <br /><br />
 
      <b>Product List</b>
 
      <asp:DataGrid id="ItemsGrid"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           ShowFooter="True"
           AutoGenerateColumns="False"
           runat="server">

         <HeaderStyle BackColor="#00aaaa">
         </HeaderStyle>

         <FooterStyle BackColor="#00aaaa">
         </FooterStyle>

         <Columns>

            <asp:BoundColumn DataField="IntegerValue"
                 Visible="True" 
                 HeaderText="Item"/>

            <asp:BoundColumn DataField="StringValue"
                 Visible="True"  
                 HeaderText="Description"/>

            <asp:BoundColumn DataField="CurrencyValue"
                 Visible="True"  
                 HeaderText="Price"
                 DataFormatString="{0:c}">

               <ItemStyle HorizontalAlign="Right">
               </ItemStyle>

            </asp:BoundColumn>

            <asp:TemplateColumn HeaderText="Select Item"
                 Visible="True" >

               <ItemTemplate>

                  <asp:CheckBox id="SelectCheckBox"
                       Text="Add to Cart"
                       Checked="False"
                       runat="server"/>

               </ItemTemplate>

            </asp:TemplateColumn>
 
         </Columns> 
 
      </asp:DataGrid>

      <br /><br />

      <asp:Button id="SubmitButton"
           Text="Submit"
           OnClick = "Button_Click"
           runat="server"/>

      <br /><br />

      <asp:Label id="Message"
           runat="server"/>

      <hr />

      <asp:CheckBox id="ShowCheckBox"
           Text="Show first column"
           AutoPostBack="True"
           OnCheckedChanged="Check_Change"
           Checked="True"
           runat="server"/>
 
   </form>
 
</body>
</html>

Commenti

Usare la Items a livello di programmazione gli elementi nella raccolta di DataGrid controllo.Use the Items collection to programmatically control the items in the DataGrid control. Il Items raccolta non fornisce alcun metodo per aggiungere o rimuovere elementi nell'insieme.The Items collection does not provide any methods to add or remove items to the collection. Tuttavia, è possibile controllare il contenuto di un elemento, fornendo un gestore per il ItemCreated evento.However, you can control the contents of an item by providing a handler for the ItemCreated event.

Nota

Solo gli elementi associati all'origine dati sono contenuti nel Items raccolta.Only items bound to the data source are contained in the Items collection. L'intestazione, piè di pagina e separatore non sono inclusi nella raccolta.The header, footer, and separator are not included in the collection.

Si applica a

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