HtmlInputImage.CausesValidation Proprietà

  • Riferimento

Definizione

Spazio dei nomi:
System.Web.UI.HtmlControls
Assembly:
System.Web.dll

Ottiene o imposta un valore che indica se viene eseguita la convalida quando si fa clic sul controllo HtmlInputImage.

public:
 property bool CausesValidation { bool get(); void set(bool value); };
public:
 virtual property bool CausesValidation { bool get(); void set(bool value); };
public bool CausesValidation { get; set; }
public virtual bool CausesValidation { get; set; }
member this.CausesValidation : bool with get, set
Public Property CausesValidation As Boolean
Public Overridable Property CausesValidation As Boolean

Valore della proprietà

Boolean

true se viene eseguita la convalida quando si fa clic sul controllo HtmlInputImage; in caso contrario, false. Il valore predefinito è true.

Esempio

Nell'esempio di codice seguente viene illustrato come utilizzare la CausesValidation proprietà per impedire che si verifichi la convalida della pagina. Si noti che il Validate metodo attiva ogni controllo di convalida in modo indipendente.


<%@ Page Language="C#" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  void SubmitButton_Click(Object sender, ImageClickEventArgs e)
  {

    // Determine which button was clicked.
    switch (((HtmlInputImage)sender).ID)
    {

      case "CityQueryButton":

        // Validate only the controls used for the city query.
        CityReqValidator.Validate();

        // Take the appropriate action if the controls pass validation. 
        if (CityReqValidator.IsValid)
        {
          Message.InnerHtml = "You have chosen to run a query for the following city: " +
             CityTextBox.Value;
        }

        break;

      case "StateQueryButton":

        // Validate only the controls used for the state query.
        StateReqValidator.Validate();

        // Take the appropriate action if the controls pass validation.
        if (StateReqValidator.IsValid)
        {
          Message.InnerHtml = "You have chosen to run a query for the following state: " +
             StateTextBox.Value;
        }

        break;

      default:

        // If the button clicked is not recognized, erase the message on the page.
        Message.InnerHtml = "";

        break;

    }

  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" > 
<head>
    <title> HtmlInputImage CausesValidation Example </title>
</head>

<body>

   <form id="form1" runat="server">

      <h3> HtmlInputImage CausesValidation Example </h3>

      <table border="1" cellpadding="10">

         <tr>
            <td>
               <b>Enter city to query.</b> <br />
               <input id="CityTextBox" 
                      type="Text"
                      runat="server"/>
               <asp:RequiredFieldValidator 
                      ID="CityReqValidator"
                      ControlToValidate="CityTextBox"
                      ErrorMessage="<br />Please enter a city."
                      Display="Dynamic"
                      EnableClientScript="False"
                      runat="server"/>
            </td>
            <td valign="bottom">
               <input id="CityQueryButton"
                      alt="City Submit button"
                      type="Image"
                      src="image.jpg"
                      causesvalidation="False"
                      onserverclick="SubmitButton_Click"
                      runat="server"/>
            </td>
         </tr>

         <tr>
            <td>
               <b>Enter state to query.</b> <br />
               <input id="StateTextBox" 
                      type="Text" 
                      runat="server"/>
               <asp:RequiredFieldValidator ID="StateReqValidator"
                      ControlToValidate="StateTextBox"
                      ErrorMessage="<br />Please enter a state."
                      Display="Dynamic"
                      EnableClientScript="False"
                      runat="server"/>
            </td>
            <td valign="bottom">
               <input id="StateQueryButton"
                      alt="State Submit button"
                      type="Image"
                      src="image.jpg"
                      causesvalidation="False"
                      onserverclick="SubmitButton_Click"
                      runat="server"/>
            </td>
         </tr>

      </table>

      <br /><br />

      <span id="Message"
            runat="Server"/>


   </form>

</body>
</html>


<%@ Page Language="VB" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  Sub SubmitButton_Click(ByVal sender As Object, ByVal e As ImageClickEventArgs)
         
    ' Determine which button was clicked.
    Select Case (CType(sender, HtmlInputImage)).ID

      Case "CityQueryButton"

        ' Validate only the controls used for the city query.
        CityReqValidator.Validate()

        ' Take the appropriate action if the controls pass validation. 
        If CityReqValidator.IsValid Then
           
          Message.InnerHtml = "You have chosen to run a query for the following city: " & _
             CityTextBox.Value
               
        End If

      Case "StateQueryButton"

        ' Validate only the controls used for the state query.
        StateReqValidator.Validate()

        ' Take the appropriate action if the controls pass validation.
        If StateReqValidator.IsValid Then
               
          Message.InnerHtml = "You have chosen to run a query for the following state: " & _
             StateTextBox.Value
               
        End If

      Case Else

        ' If the button clicked isn not recognized, erase the message on the page.
        Message.InnerHtml = ""

    End Select
        
  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" > 
<head>
    <title> HtmlInputImage CausesValidation Example </title>
</head>

<body>

   <form id="form1" runat="server">

      <h3> HtmlInputImage CausesValidation Example </h3>

      <table border="1" cellpadding="10">

         <tr>
            <td>
               <b>Enter city to query.</b> <br />
               <input id="CityTextBox" 
                      type="Text"
                      runat="server"/>
               <asp:RequiredFieldValidator ID="CityReqValidator"
                      ControlToValidate="CityTextBox"
                      ErrorMessage="<br />Please enter a city."
                      Display="Dynamic"
                      EnableClientScript="False"
                      runat="server"/>
            </td>
            <td valign="bottom">
               <input id="CityQueryButton"
                      alt="City Submit button"
                      type="Image"
                      src="SubmitImage.jpg"
                      causesvalidation="False"
                      onserverclick="SubmitButton_Click"
                      runat="server"/>
            </td>
         </tr>

         <tr>
            <td>
               <b>Enter state to query.</b> <br />
               <input id="StateTextBox" 
                      type="Text" 
                      runat="server"/>
               <asp:RequiredFieldValidator ID="StateReqValidator"
                      ControlToValidate="StateTextBox"
                      ErrorMessage="<br />Please enter a state."
                      Display="Dynamic"
                      EnableClientScript="False"
                      runat="server"/>
            </td>
            <td valign="bottom">
               <input id="StateQueryButton"
                      alt="State Submit button"
                      type="Image"
                      src="SubmitImage.jpg"
                      causesvalidation="False"
                      onserverclick="SubmitButton_Click"
                      runat="server"/>
            </td>
         </tr>

      </table>

      <br /><br />

      <span id="Message"
            runat="Server"/>


   </form>

</body>
</html>

Commenti

Per impostazione predefinita, la convalida della pagina viene eseguita quando si fa clic su un HtmlInputImage controllo . La convalida della pagina determina se i controlli di input associati a un controllo di convalida nella pagina superano tutte le regole di convalida specificate dal controllo di convalida.

È possibile specificare o determinare se la convalida viene eseguita sia sul client che sul server quando si fa clic su un HtmlInputImage controllo utilizzando la CausesValidation proprietà . Per impedire l'esecuzione della convalida, impostare la CausesValidation proprietà su false.

Questa proprietà viene comunemente utilizzata nel gestore eventi per l'evento ServerClick per impedire che si verifichi la convalida della pagina quando si fa clic su un pulsante Annulla o Reimposta.

Si applica a

Vedi anche