DynamicQueryStringParameter Class
Automatically generates a collection of parameters that is used to create the Where clause for the data source control by retrieving query string values.
Assembly: System.Web.DynamicData (in System.Web.DynamicData.dll)
System.Web.UI.WebControls.Parameter
System.Web.DynamicData.DynamicQueryStringParameter
| Name | Description | |
|---|---|---|
![]() | DynamicQueryStringParameter() | Initializes a new instance of the DynamicQueryStringParameter class. |
| Name | Description | |
|---|---|---|
![]() | ConvertEmptyStringToNull | Gets or sets a value indicating whether the value that the Parameter object is bound to should be converted to null if it is String.Empty.(Inherited from Parameter.) |
![]() | DbType | Gets or sets the database type of the parameter.(Inherited from Parameter.) |
![]() | DefaultValue | |
![]() | Direction | |
![]() | IsTrackingViewState | |
![]() | Name | Gets or sets the name of the parameter.(Inherited from Parameter.) |
![]() | Size | Gets or sets the size of the parameter.(Inherited from Parameter.) |
![]() | Type | Gets or sets the type of the parameter.(Inherited from Parameter.) |
![]() | ViewState |
| Name | Description | |
|---|---|---|
![]() | Clone() | |
![]() | Equals(Object) | Determines whether the specified object is equal to the current object.(Inherited from Object.) |
![]() | Evaluate(HttpContext, Control) | Throws an InvalidOperationException exception in all cases.(Overrides Parameter.Evaluate(HttpContext, Control).) |
![]() | Finalize() | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.) |
![]() | GetDatabaseType() | |
![]() | GetHashCode() | Serves as the default hash function. (Inherited from Object.) |
![]() | GetType() | |
![]() | GetWhereParameters(IDynamicDataSource) | Returns a collection of Parameter objects that are automatically generated for the columns of a table by retrieving query string values. |
![]() | LoadViewState(Object) | Restores the data source view's previously saved view state.(Inherited from Parameter.) |
![]() | MemberwiseClone() | |
![]() | OnParameterChanged() | Calls the OnParametersChanged method of the ParameterCollection collection that contains the Parameter object.(Inherited from Parameter.) |
![]() | SaveViewState() | |
![]() | SetDirty() | |
![]() | ToString() | Converts the value of this instance to its equivalent string representation.(Inherited from Parameter.) |
![]() | TrackViewState() |
| Name | Description | |
|---|---|---|
![]() ![]() | ICloneable.Clone() | |
![]() ![]() | IStateManager.LoadViewState(Object) | This API supports the product infrastructure and is not intended to be used directly from your code. Restores the data source view's previously saved view state.(Inherited from Parameter.) |
![]() ![]() | IStateManager.SaveViewState() | |
![]() ![]() | IStateManager.TrackViewState() | |
![]() ![]() | IStateManager.IsTrackingViewState |
The DynamicQueryStringParameter class is used by pages that are using ASP.NET Dynamic Data features. The DynamicQueryStringParameter class will generate a collection of Parameter objects for the primary keys, foreign keys, and Boolean columns of a table by retrieving query string values.
For primary keys, you can simply add a DynamicQueryStringParameter object without supplying any other parameters. Dynamic Data will generate the parameters for the primary key or keys. For foreign keys or Boolean columns, you must set the Name property to the name of the column you want to filter.
In order to use the DynamicQueryStringParameter class, you must add a DynamicDataManager control to the page and you must register the data-bound control with the DynamicDataManager control by using the DynamicDataManager.RegisterControl method.
See a run-time code example of this feature: Run.
The following example shows how to use the DynamicQueryStringParameter object as filter when displaying data in a GridView control. The GridView control contains a TemplateField object that creates a link that sets the query string value by using the foreign key value.
<%@ Page Language="VB" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) ' Registers the data-bound control with ' the DynamicDataManager control. DynamicDataManager1.RegisterControl(ProductsGridView) ' Initializes the URL for the View All link ' to the current page. ViewAllLink.NavigateUrl = Request.Path End Sub Protected Function GetFilterPath() As String ' Retrieves the current data item. Dim productItem = CType(GetDataItem(), Product) If Not (productItem.ProductCategory Is Nothing) Then ' Creates a URL that has a query string value ' set to the foreign key value. Return Request.Path + "?ProductCategoryID=" + productItem.ProductCategoryID.ToString() End If Return String.Empty End Function Protected Function GetProductCategory() As String ' Returns the value for the Name column ' in the relationship table. Dim productItem = CType(GetDataItem(), Product) If Not (productItem.ProductCategory Is Nothing) Then Return productItem.ProductCategory.Name End If Return String.Empty End Function </script> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title>DynamicQueryStringParameter Example</title> <link href="~/Site.css" rel="stylesheet" type="text/css" /> </head> <body class="template"> <form id="form1" runat="server"> <div> <h2>DynamicQueryStringParameter Example</h2> <asp:DynamicDataManager ID="DynamicDataManager1" runat="server" AutoLoadForeignKeys="true" /> <asp:GridView ID="ProductsGridView" runat="server" AutoGenerateColumns="false" DataSourceID="ProductsDataSource" AllowPaging="true" CssClass="gridview"> <Columns> <asp:DynamicField DataField="Name" /> <asp:DynamicField DataField="ProductNumber" /> <asp:DynamicField DataField="Color" /> <asp:TemplateField HeaderText="Category"> <ItemTemplate> <a runat="server" href='<%# GetFilterPath() %>'> <asp:Label runat="server" ID="ProductCategory" Text='<%# GetProductCategory() %>' /> </a> </ItemTemplate> </asp:TemplateField> </Columns> </asp:GridView> <br /> <div class="bottomhyperlink"> <asp:HyperLink runat="server" ID="ViewAllLink" Text="View All Records" /> </div> <!-- This example uses Microsoft SQL Server and connects --> <!-- to the AdventureWorksLT sample database. --> <asp:LinqDataSource ID="ProductsDataSource" runat="server" TableName="Products" ContextTypeName="AdventureWorksLTDataContext" > <WhereParameters> <asp:DynamicQueryStringParameter Name="ProductCategory" /> </WhereParameters> </asp:LinqDataSource> </div> </form> </body> </html>
Available since 3.5
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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