FormParameter 构造函数

定义

命名空间:: System.Web.UI.WebControls

程序集:: System.Web.dll

重要

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初始化 FormParameter 类的新实例。

重载

名称	说明
FormParameter()	初始化类的新未命名实例 FormParameter 。
FormParameter(FormParameter)	使用参数指定的`original`实例的值初始化类的新实例FormParameter。
FormParameter(String, String)	使用指定的字符串标识要绑定到的 FormParameter 表单变量字段，初始化类的新命名实例。
FormParameter(String, DbType, String)	使用指定的字符串标识要绑定到的 FormParameter 表单变量字段，初始化类的新实例。
FormParameter(String, TypeCode, String)	使用指定的字符串来标识要绑定到的 FormParameter 表单变量，初始化类的新命名和强类型实例。

FormParameter()

初始化类的新未命名实例 FormParameter 。

public:
 FormParameter();

public FormParameter();

Public Sub New ()

示例

重要

它 FormParameter 不会以任何方式验证表单元素传递的值;它使用原始值。在大多数情况下，可以通过处理正在使用的FormParameter数据源控件公开的事件（例如Selecting、UpdatingInserting或Deleting事件）来验证数据源控件使用之前的值。如果参数的值未通过验证测试，可以通过将关联CancelEventArgs类的属性设置为Canceltrue来取消数据操作。

<%@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>

注解

FormParameter使用FormParameter构造函数创建的对象使用其所有属性的默认值进行初始化。初始化 FormField 为 String.Empty. 此外，属性Name初始化为String.Empty，Type属性初始化为TypeCode.Object，Direction属性初始化为 Inputnull（DefaultValueNothing在 Visual Basic 中）。

另请参阅

将参数与数据源控件配合使用

适用于

FormParameter(FormParameter)

使用参数指定的original实例的值初始化类的新实例FormParameter。

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.FormParameter

Protected Sub New (original As FormParameter)

参数

original: FormParameter

从 FormParameter 中初始化当前实例的实例。

注解

构造 FormParameter 函数是 protected 用于克隆实例的 FormParameter 复制构造函数。 FormParameter值（包括FormField）Name和Type全部传输到新实例。

另请参阅

适用于

FormParameter(String, String)

使用指定的字符串标识要绑定到的 FormParameter 表单变量字段，初始化类的新命名实例。

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.FormParameter

Public Sub New (name As String, formField As String)

参数

name: String

参数的名称。

formField: String

参数对象绑定到的窗体变量的名称。默认值为 Empty。

示例

重要

<%@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>

注解

FormParameter使用FormParameter构造函数创建的对象使用指定的参数名称和字符串进行初始化，用于标识参数绑定到的表单变量。使用 Type 默认值初始化属性 Direction 。

另请参阅

适用于

FormParameter(String, DbType, String)

使用指定的字符串标识要绑定到的 FormParameter 表单变量字段，初始化类的新实例。

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.FormParameter

Public Sub New (name As String, dbType As DbType, formField As String)

参数

name: String

参数的名称。

dbType: DbType

参数的数据库类型。

formField: String

参数对象绑定到的窗体变量的名称。

适用于

FormParameter(String, TypeCode, String)

使用指定的字符串来标识要绑定到的 FormParameter 表单变量，初始化类的新命名和强类型实例。

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.FormParameter

Public Sub New (name As String, type As TypeCode, formField As String)

参数

name: String

参数的名称。

type: TypeCode

参数表示的类型。默认值为 Object。

formField: String

参数对象绑定到的窗体变量的名称。默认值为 Empty。

示例

重要

<%@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>

注解

FormParameter使用FormParameter构造函数创建的对象使用指定的参数名称和Type标识参数绑定到的表单变量的字符串进行初始化。仅使用 Direction 默认值初始化和 ConvertEmptyStringToNull 属性。

另请参阅

适用于

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