DataGridItemCollection Class
Represents a collection of DataGridItem objects in a DataGrid control.
Assembly: System.Web (in System.Web.dll)
| Name | Description | |
|---|---|---|
![]() | DataGridItemCollection(ArrayList) | Initializes a new instance of the DataGridItemCollection class. |
| Name | Description | |
|---|---|---|
![]() | Count | Gets the number of DataGridItem objects in the collection. |
![]() | IsReadOnly | Gets a value that indicates whether the DataGridItem objects in the DataGridItemCollection collection can be modified. |
![]() | IsSynchronized | Gets a value indicating whether access to the DataGridItemCollection collection is synchronized (thread-safe). |
![]() | Item(Int32) | Gets the DataGridItem object at the specified index in the collection. |
![]() | SyncRoot | Gets the object that can be used to synchronize access to the DataGridItemCollection collection. |
| Name | Description | |
|---|---|---|
![]() | CopyTo(Array, Int32) | Copies all the items from this DataGridItemCollection collection to the specified System.Array, starting at the specified index in the System.Array. |
![]() | Equals(Object) | Determines whether the specified object is equal to the current object.(Inherited from Object.) |
![]() | Finalize() | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.) |
![]() | GetEnumerator() | Returns a System.Collections.IEnumerator-implemented object that contains all the DataGridItem objects in the DataGridItemCollection collection. |
![]() | GetHashCode() | Serves as the default hash function. (Inherited from Object.) |
![]() | GetType() | |
![]() | MemberwiseClone() | |
![]() | ToString() | Returns a string that represents the current object.(Inherited from Object.) |
| Name | Description | |
|---|---|---|
![]() | AsParallel() | Overloaded. Enables parallelization of a query.(Defined by ParallelEnumerable.) |
![]() | AsQueryable() | Overloaded. Converts an IEnumerable to an IQueryable.(Defined by Queryable.) |
![]() | Cast(Of TResult)() | Casts the elements of an IEnumerable to the specified type.(Defined by Enumerable.) |
![]() | OfType(Of TResult)() | Filters the elements of an IEnumerable based on a specified type.(Defined by Enumerable.) |
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, 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.
The following code example shows how to iterate through DataGridItem objects in a DataGridItemCollection collection.
<%@ 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>
Available since 1.1
Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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