ImageButton.CausesValidation Property
Definition
Important
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Gets or sets a value indicating whether validation is performed when the ImageButton control is clicked.
public:
property bool CausesValidation { bool get(); void set(bool value); };public:
virtual property bool CausesValidation { bool get(); void set(bool value); };[System.ComponentModel.Bindable(false)]
public bool CausesValidation { get; set; }[System.Web.UI.Themeable(false)]
public virtual bool CausesValidation { get; set; }[<System.ComponentModel.Bindable(false)>]
member this.CausesValidation : bool with get, set[<System.Web.UI.Themeable(false)>]
member this.CausesValidation : bool with get, setPublic Property CausesValidation As BooleanPublic Overridable Property CausesValidation As BooleanProperty Value
true if validation is performed when the ImageButton control is clicked; otherwise, false. The default value is true.
Implements
- Attributes
Examples
The following example demonstrates how to use the CausesValidation property to prevent page validation from occurring. Notice how the Validate method activates each validation control independently.
Note
The following code sample uses the single-file code model and may not work correctly if copied directly into a code-behind file. This code sample must be copied into an empty text file that has an .aspx extension. For more information on the Web Forms code model, see ASP.NET Web Forms Page Code Model.
<%@ 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">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title> ImageButton CausesValidation Example </title>
<script runat="server">
void SubmitButton_Click(Object sender, ImageClickEventArgs e)
{
// Determine which button was clicked.
switch(((ImageButton)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.Text = "You have chosen to run a query for the following city: " +
CityTextBox.Text;
}
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.Text = "You have chosen to run a query for the following state: " +
StateTextBox.Text;
}
break;
default:
// If the button clicked isn't recognized, erase the message on the page.
Message.Text = "";
break;
}
}
</script>
</head>
<body>
<form id="form1" runat="server">
<h3> ImageButton CausesValidation Example </h3>
<table border="1" cellpadding="10">
<tr>
<td>
<b>Enter city to query.</b> <br />
<asp:TextBox ID="CityTextBox"
runat="server"/>
<asp:RequiredFieldValidator ID="CityReqValidator"
ControlToValidate="CityTextBox"
ErrorMessage="<br />Please enter a city."
Display="Dynamic"
EnableClientScript="False"
runat="server"/>
</td>
<td valign="bottom">
<asp:ImageButton ID="CityQueryButton"
ImageUrl="SubmitImage.jpg"
CausesValidation="False"
OnClick="SubmitButton_Click"
runat="server"/>
</td>
</tr>
<tr>
<td>
<b>Enter state to query.</b> <br />
<asp:TextBox ID="StateTextBox"
runat="server"/>
<asp:RequiredFieldValidator ID="StateReqValidator"
ControlToValidate="StateTextBox"
ErrorMessage="<br />Please enter a state."
Display="Dynamic"
EnableClientScript="False"
runat="server"/>
</td>
<td valign="bottom">
<asp:ImageButton ID="StateQueryButton"
ImageUrl="SubmitImage.jpg"
CausesValidation="False"
OnClick="SubmitButton_Click"
runat="server"/>
</td>
</tr>
</table>
<br /><br />
<asp:Label 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">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title> ImageButton CausesValidation Example </title>
<script runat="server">
Sub SubmitButton_Click(sender As Object, e As ImageClickEventArgs)
' Determine which button was clicked.
Select Case (CType(sender, ImageButton)).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.Text = "You have chosen to run a query for the following city: " & _
CityTextBox.Text
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.Text = "You have chosen to run a query for the following state: " & _
StateTextBox.Text
End If
Case Else
' If the button clicked isn't recognized, erase the message on the page.
Message.Text = ""
End Select
End Sub
</script>
</head>
<body>
<form id="form1" runat="server">
<h3> ImageButton CausesValidation Example </h3>
<table border="1" cellpadding="10">
<tr>
<td>
<b>Enter city to query.</b> <br />
<asp:TextBox ID="CityTextBox"
runat="server"/>
<asp:RequiredFieldValidator ID="CityReqValidator"
ControlToValidate="CityTextBox"
ErrorMessage="<br />Please enter a city."
Display="Dynamic"
EnableClientScript="False"
runat="server"/>
</td>
<td valign="bottom">
<asp:ImageButton ID="CityQueryButton"
ImageUrl="SubmitImage.jpg"
CausesValidation="False"
OnClick="SubmitButton_Click"
runat="server"/>
</td>
</tr>
<tr>
<td>
<b>Enter state to query.</b> <br />
<asp:TextBox ID="StateTextBox"
runat="server"/>
<asp:RequiredFieldValidator ID="StateReqValidator"
ControlToValidate="StateTextBox"
ErrorMessage="<br />Please enter a state."
Display="Dynamic"
EnableClientScript="False"
runat="server"/>
</td>
<td valign="bottom">
<asp:ImageButton ID="StateQueryButton"
ImageUrl="SubmitImage.jpg"
CausesValidation="False"
OnClick="SubmitButton_Click"
runat="server"/>
</td>
</tr>
</table>
<br /><br />
<asp:Label ID="Message"
runat="Server"/>
</form>
</body>
</html>
Remarks
By default, page validation is performed when an ImageButton control is clicked. Page validation determines whether the input controls associated with a validation control on the page all pass the validation rules specified by the validation control.
You can specify or determine whether validation is performed on both the client and the server when an ImageButton control is clicked by using the CausesValidation property. To prevent validation from being performed, set the CausesValidation property to false.
This property is commonly set to false for a Reset or Clear button to prevent validation from being performed when the button is clicked.
When the value of the CausesValidation property is set to true, you can also use the ValidationGroup property to specify the name of the validation group for which the ImageButton control causes validation.
This property cannot be set by themes or style sheet themes. For more information, see ThemeableAttribute and ASP.NET Themes and Skins.
