HtmlInputImage.CausesValidation 屬性
定義
重要
部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。
取得或設定值，指出按一下 HtmlInputImage 控制項時，是否執行驗證。
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, setPublic Property CausesValidation As BooleanPublic Overridable Property CausesValidation As Boolean屬性值
如果按一下 HtmlInputImage 控制項時會執行驗證，則為 true；否則為 false。 預設值是 true。
範例
下列程式碼範例示範如何使用 CausesValidation 屬性來防止頁面驗證發生。 請注意方法如何 Validate 獨立啟動每個驗證控制項。
<%@ 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>
備註
根據預設，按一下控制項時 HtmlInputImage ，會執行頁面驗證。 頁面驗證會判斷頁面上與驗證控制項相關聯的輸入控制項是否通過驗證控制項所指定的驗證規則。
您可以使用 屬性來指定或判斷是否在用戶端和伺服器上 HtmlInputImageCausesValidation 執行驗證。 若要防止執行驗證，請將 CausesValidation 屬性設定為 false 。
這個屬性通常用於 事件的事件處理常式 ServerClick ，以防止按一下 [取消] 或 [重設] 按鈕時發生頁面驗證。
