DataGridItemCollection Class
Represents a collection of DataGridItem objects in a DataGrid control.
For a list of all members of this type, see DataGridItemCollection Members.
System.Object
System.Web.UI.WebControls.DataGridItemCollection
[Visual Basic] Public Class DataGridItemCollection Implements ICollection, IEnumerable [C#] public class DataGridItemCollection : ICollection, IEnumerable [C++] public __gc class DataGridItemCollection : public ICollection, IEnumerable [JScript] public class DataGridItemCollection implements ICollection, IEnumerable
Thread Safety
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Remarks
The DataGridItemCollection class represents a collection of DataGridItem objects, which in turn represent the data items in a DataGrid control. To programmatically retrieve DataGridItem objects from a DataGrid control, use one of following methods:
- Use the indexer to get a single DataGridItem object from the collection, using array notation.
- Use the CopyTo method to copy the contents of the collection to a System.Array object, which can then be used to get items from the collection.
- Use the GetEnumerator method to create a System.Collections.IEnumerator interface, which can then be used to get items from the collection.
The Count property specifies the total number of items in the collection and is commonly used to determine the upper bound of the collection.
Example
[Visual Basic] <%@ Page Language="VB" AutoEventWireup="True" %> <%@ Import Namespace="System.Data" %> <html> <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> <body> <form 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> [C#] <%@ Page Language="C#" AutoEventWireup="True" %> <%@ Import Namespace="System.Data" %> <html> <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> <body> <form 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>
[C++, JScript] No example is available for C++ or JScript. To view a Visual Basic or C# example, click the Language Filter button
in the upper-left corner of the page.
Requirements
Namespace: System.Web.UI.WebControls
Platforms: Windows 2000, Windows XP Professional, Windows Server 2003 family
Assembly: System.Web (in System.Web.dll)
See Also
DataGridItemCollection Members | System.Web.UI.WebControls Namespace | DataGridItem | DataGrid | Items | CopyTo | GetEnumerator | Count