FormParameter Constructors
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Initializes a new instance of the FormParameter class.
Overloads
| FormParameter() |
Initializes a new unnamed instance of the FormParameter class. |
| FormParameter(FormParameter) |
Initializes a new instance of the FormParameter class with the values of the instance specified by the |
| FormParameter(String, String) |
Initializes a new named instance of the FormParameter class, using the specified string to identify which form variable field to bind to. |
| FormParameter(String, DbType, String) |
Initializes a new instance of the FormParameter class, using the specified string to identify which form variable field to bind to. |
| FormParameter(String, TypeCode, String) |
Initializes a new named and strongly typed instance of the FormParameter class, using the specified string to identify which form variable to bind to. |
FormParameter()
Initializes a new unnamed instance of the FormParameter class.
public:
FormParameter();public FormParameter ();Public Sub New ()Examples
Important
The FormParameter does not validate the value passed by the form element in any way; it uses the raw value. In most cases, you can validate the value of the FormParameter before it is used by a data source control by handling an event, such as the Selecting, Updating, Inserting, or Deleting event exposed by the data source control you are using. If the value of the parameter does not pass your validation tests, you can cancel the data operation by setting the Cancel property of the associated CancelEventArgs class to true.
<%@Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
void Page_Load(Object sender, EventArgs e){
// You can add a FormParameter to the AccessDataSource control's
// SelectParameters collection programmatically.
AccessDataSource1.SelectParameters.Clear();
// Security Note: The AccessDataSource uses a FormParameter,
// Security Note: which does not perform validation of input from the client.
// Security Note: To validate the value of the FormParameter,
// Security Note: handle the Selecting event.
FormParameter formParam = new FormParameter();
formParam.Name="lastname";
formParam.Type=TypeCode.String;
formParam.FormField="LastNameBox";
AccessDataSource1.SelectParameters.Add(formParam);
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<asp:accessdatasource
id="AccessDataSource1"
runat="server"
datasourcemode="DataSet"
datafile="Northwind.mdb"
selectcommand="SELECT OrderID,CustomerID,OrderDate,RequiredDate,ShippedDate
FROM Orders WHERE EmployeeID =
(SELECT EmployeeID FROM Employees WHERE LastName = @lastname)">
</asp:accessdatasource>
<br />Enter the name "Davolio" or "King" in the text box and click the button.
<br />
<asp:textbox
id="LastNameBox"
runat="server" />
<br />
<asp:button
id="Button1"
runat="server"
text="Get Records" />
<br />
<asp:gridview
id="GridView1"
runat="server"
allowsorting="True"
datasourceid="AccessDataSource1" />
</form>
</body>
</html>
<%@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">
Private Sub Page_Load(sender As Object, e As EventArgs)
' You can add a FormParameter to the AccessDataSource control's
' SelectParameters collection programmatically.
AccessDataSource1.SelectParameters.Clear()
' Security Note: The AccessDataSource uses a FormParameter,
' Security Note: which does not perform validation of input from the client.
' Security Note: To validate the value of the FormParameter,
' Security Note: handle the Selecting event.
Dim formParam As New FormParameter()
formParam.Name="lastname"
formParam.Type=TypeCode.String
formParam.FormField="LastNameBox"
AccessDataSource1.SelectParameters.Add(formParam)
End Sub ' Page_Load
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<asp:accessdatasource
id="AccessDataSource1"
runat="server"
datasourcemode="DataSet"
datafile="Northwind.mdb"
selectcommand="SELECT OrderID,CustomerID,OrderDate,RequiredDate,ShippedDate
FROM Orders WHERE EmployeeID =
(SELECT EmployeeID FROM Employees WHERE LastName = @lastname)">
</asp:accessdatasource>
<br />Enter the name "Davolio" or "King" in the text box and click the button.
<br />
<asp:textbox
id="LastNameBox"
runat="server" />
<br />
<asp:button
id="Button1"
runat="server"
text="Get Records" />
<br />
<asp:gridview
id="GridView1"
runat="server"
allowsorting="True"
datasourceid="AccessDataSource1" />
</form>
</body>
</html>
Remarks
A FormParameter object created with the FormParameter constructor is initialized with default values for all its properties. The FormField is initialized to String.Empty. Additionally, the Name property is initialized to String.Empty, the Type property is initialized to TypeCode.Object, the Direction property is initialized to Input, and the DefaultValue property is initialized to null (Nothing in Visual Basic).
See also
Applies to
FormParameter(FormParameter)
Initializes a new instance of the FormParameter class with the values of the instance specified by the original parameter.
protected:
FormParameter(System::Web::UI::WebControls::FormParameter ^ original);protected FormParameter (System.Web.UI.WebControls.FormParameter original);new System.Web.UI.WebControls.FormParameter : System.Web.UI.WebControls.FormParameter -> System.Web.UI.WebControls.FormParameterProtected Sub New (original As FormParameter)Parameters
- original
- FormParameter
A FormParameter instance that the current instance is initialized from.
Remarks
The FormParameter constructor is a protected copy constructor used to clone a FormParameter instance. The values of the FormParameter, including FormField, Name, and Type are all transferred to the new instance.
See also
Applies to
FormParameter(String, String)
Initializes a new named instance of the FormParameter class, using the specified string to identify which form variable field to bind to.
public:
FormParameter(System::String ^ name, System::String ^ formField);public FormParameter (string name, string formField);new System.Web.UI.WebControls.FormParameter : string * string -> System.Web.UI.WebControls.FormParameterPublic Sub New (name As String, formField As String)Parameters
- name
- String
The name of the parameter.
- formField
- String
The name of the form variable that the parameter object is bound to. The default is Empty.
Examples
Important
The FormParameter does not validate the value passed by the form element in any way; it uses the raw value. In most cases, you can validate the value of the FormParameter before it is used by a data source control by handling an event, such as the Selecting, Updating, Inserting, or Deleting event exposed by the data source control you are using. If the value of the parameter does not pass your validation tests, you can cancel the data operation by setting the Cancel property of the associated CancelEventArgs class to true.
<%@Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
void Page_Load(Object sender, EventArgs e){
// You can add a FormParameter to the AccessDataSource control's
// SelectParameters collection programmatically.
AccessDataSource1.SelectParameters.Clear();
// Security Note: The AccessDataSource uses a FormParameter,
// Security Note: which does not perform validation of input from the client.
// Security Note: To validate the value of the FormParameter,
// Security Note: handle the Selecting event.
FormParameter formParam = new FormParameter("lastname","LastNameBox");
formParam.Type=TypeCode.String;
AccessDataSource1.SelectParameters.Add(formParam);
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<asp:accessdatasource
id="AccessDataSource1"
runat="server"
datasourcemode="DataSet"
datafile="Northwind.mdb"
selectcommand="SELECT OrderID,CustomerID,OrderDate,RequiredDate,ShippedDate
FROM Orders WHERE EmployeeID =
(SELECT EmployeeID FROM Employees WHERE LastName = @lastname)">
</asp:accessdatasource>
<br />Enter the name "Davolio" or "King" in the text box and click the button.
<br />
<asp:textbox
id="LastNameBox"
runat="server" />
<br />
<asp:button
id="Button1"
runat="server"
text="Get Records" />
<br />
<asp:gridview
id="GridView1"
runat="server"
allowsorting="True"
datasourceid="AccessDataSource1">
</asp:gridview>
</form>
</body>
</html>
<%@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">
Private Sub Page_Load(sender As Object, e As EventArgs)
' You can add a FormParameter to the AccessDataSource control's
' SelectParameters collection programmatically.
AccessDataSource1.SelectParameters.Clear()
' Security Note: The AccessDataSource uses a FormParameter,
' Security Note: which does not perform validation of input from the client.
' Security Note: To validate the value of the FormParameter,
' Security Note: handle the Selecting event.
Dim formParam As New FormParameter("lastname","LastNameBox")
formParam.Type=TypeCode.String
AccessDataSource1.SelectParameters.Add(formParam)
End Sub ' Page_Load
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<asp:accessdatasource
id="AccessDataSource1"
runat="server"
datasourcemode="DataSet"
datafile="Northwind.mdb"
selectcommand="SELECT OrderID,CustomerID,OrderDate,RequiredDate,ShippedDate
FROM Orders WHERE EmployeeID =
(SELECT EmployeeID FROM Employees WHERE LastName = @lastname)">
</asp:accessdatasource>
<br />Enter the name "Davolio" or "King" in the text box and click the button.
<br />
<asp:textbox
id="LastNameBox"
runat="server" />
<br />
<asp:button
id="Button1"
runat="server"
text="Get Records" />
<br />
<asp:gridview
id="GridView1"
runat="server"
allowsorting="True"
datasourceid="AccessDataSource1">
</asp:gridview>
</form>
</body>
</html>
Remarks
A FormParameter object created with the FormParameter constructor is initialized with the specified parameter name and string that identifies the form variable that the parameter binds to. The Type and Direction properties are initialized with default values.
See also
Applies to
FormParameter(String, DbType, String)
Initializes a new instance of the FormParameter class, using the specified string to identify which form variable field to bind to.
public:
FormParameter(System::String ^ name, System::Data::DbType dbType, System::String ^ formField);public FormParameter (string name, System.Data.DbType dbType, string formField);new System.Web.UI.WebControls.FormParameter : string * System.Data.DbType * string -> System.Web.UI.WebControls.FormParameterPublic Sub New (name As String, dbType As DbType, formField As String)Parameters
- name
- String
The name of the parameter.
- dbType
- DbType
The database type of the parameter.
- formField
- String
The name of the form variable that the parameter object is bound to.
Applies to
FormParameter(String, TypeCode, String)
Initializes a new named and strongly typed instance of the FormParameter class, using the specified string to identify which form variable to bind to.
public:
FormParameter(System::String ^ name, TypeCode type, System::String ^ formField);public FormParameter (string name, TypeCode type, string formField);new System.Web.UI.WebControls.FormParameter : string * TypeCode * string -> System.Web.UI.WebControls.FormParameterPublic Sub New (name As String, type As TypeCode, formField As String)Parameters
- name
- String
The name of the parameter.
- formField
- String
The name of the form variable that the parameter object is bound to. The default is Empty.
Examples
Important
The FormParameter does not validate the value passed by the form element in any way; it uses the raw value. In most cases, you can validate the value of the FormParameter before it is used by a data source control by handling an event, such as the Selecting, Updating, Inserting, or Deleting event exposed by the data source control you are using. If the value of the parameter does not pass your validation tests, you can cancel the data operation by setting the Cancel property of the associated CancelEventArgs class to true.
<%@Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
void Page_Load(Object sender, EventArgs e){
// You can add a FormParameter to the AccessDataSource control's
// SelectParameters collection programmatically.
AccessDataSource1.SelectParameters.Clear();
// Security Note: The AccessDataSource uses a FormParameter,
// Security Note: which does not perform validation of input from the client.
// Security Note: To validate the value of the FormParameter,
// Security Note: handle the Selecting event.
FormParameter formParam = new FormParameter("lastname", TypeCode.String, "LastNameBox");
AccessDataSource1.SelectParameters.Add(formParam);
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<asp:accessdatasource
id="AccessDataSource1"
runat="server"
datasourcemode="DataSet"
datafile="Northwind.mdb"
selectcommand="SELECT OrderID,CustomerID,OrderDate,RequiredDate,ShippedDate
FROM Orders WHERE EmployeeID =
(SELECT EmployeeID FROM Employees WHERE LastName = @lastname)">
</asp:accessdatasource>
<br />Enter the name "Davolio" or "King" in the text box and click the button.
<br />
<asp:textbox
id="LastNameBox"
runat="server" />
<br />
<asp:button
id="Button1"
runat="server"
text="Get Records" />
<br />
<asp:gridview
id="GridView1"
runat="server"
allowsorting="True"
datasourceid="AccessDataSource1">
</asp:gridview>
</form>
</body>
</html>
<%@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">
Private Sub Page_Load(sender As Object, e As EventArgs)
' You can add a FormParameter to the AccessDataSource control's
' SelectParameters collection programmatically.
AccessDataSource1.SelectParameters.Clear()
' Security Note: The AccessDataSource uses a FormParameter,
' Security Note: which does not perform validation of input from the client.
' Security Note: To validate the value of the FormParameter,
' Security Note: handle the Selecting event.
Dim formParam As New FormParameter("lastname",TypeCode.String,"LastNameBox")
AccessDataSource1.SelectParameters.Add(formParam)
End Sub ' Page_Load
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<asp:accessdatasource
id="AccessDataSource1"
runat="server"
datasourcemode="DataSet"
datafile="Northwind.mdb"
selectcommand="SELECT OrderID,CustomerID,OrderDate,RequiredDate,ShippedDate
FROM Orders WHERE EmployeeID =
(SELECT EmployeeID FROM Employees WHERE LastName = @lastname)">
</asp:accessdatasource>
<br />Enter the name "Davolio" or "King" in the text box and click the button.
<br />
<asp:textbox
id="LastNameBox"
runat="server" />
<br />
<asp:button
id="Button1"
runat="server"
text="Get Records" />
<br />
<asp:gridview
id="GridView1"
runat="server"
allowsorting="True"
datasourceid="AccessDataSource1">
</asp:gridview>
</form>
</body>
</html>
Remarks
A FormParameter object created with the FormParameter constructor is initialized with the specified parameter name, Type, and string that identifies the form variable that the parameter binds to. Only the Direction and ConvertEmptyStringToNull properties are initialized with default values.
