//在窗口关闭或隐藏时，清楚文本框中的内容（核心代码）
function(s, e) { ASPxClientEdit.ClearGroup('entryGroup'); }
<asp:Content ID="Content1" ContentPlaceHolderID="ContentHolder" runat="Server">
<script type="text/javascript">
// <![CDATA[
function ShowLoginWindow() {
pcLogin.Show();
}
function ShowCreateAccountWindow() {
pcCreateAccount.Show();
tbUsername.Focus();
}
// ]]>
</script>
<div style="margin: 16px auto; 160px;">
<dx:ASPxButton ID="btShowModal" runat="server" Text="Show Modal Window" AutoPostBack="False" UseSubmitBehavior="false" Width="100%">
<ClientSideEvents Click="function(s, e) { ShowLoginWindow(); }" />
</dx:ASPxButton>
</div>
<dx:ASPxPopupControl ID="pcLogin" runat="server" CloseAction="CloseButton" Modal="True"
PopupHorizontalAlign="WindowCenter" PopupVerticalAlign="WindowCenter" ClientInstanceName="pcLogin"
HeaderText="Login" AllowDragging="True" PopupAnimationType="None" EnableViewState="False">
<ClientSideEvents PopUp="function(s, e) { ASPxClientEdit.ClearGroup('entryGroup'); tbLogin.Focus(); }" />
<ContentCollection>
<dx:PopupControlContentControl runat="server">
<dx:ASPxPanel ID="Panel1" runat="server" DefaultButton="btOK">
<PanelCollection>
<dx:PanelContent runat="server">
<table>
<tr>
<td rowspan="4">
<div class="pcmSideSpacer">
</div>
</td>
<td class="pcmCellCaption">
<dx:ASPxLabel ID="lblUsername1" runat="server" Text="Username:" AssociatedControlID="tbLogin">
</dx:ASPxLabel>
</td>
<td class="pcmCellText">
<dx:ASPxTextBox ID="tbLogin" runat="server" Width="150px" ClientInstanceName="tbLogin">
<ValidationSettings EnableCustomValidation="True" ValidationGroup="entryGroup" SetFocusOnError="True"
ErrorDisplayMode="Text" ErrorTextPosition="Bottom" CausesValidation="True">
<RequiredField ErrorText="Username required" IsRequired="True" />
<RegularExpression ErrorText="Login required" />
<ErrorFrameStyle Font-Size="10px">
<ErrorTextPaddings PaddingLeft="0px" />
</ErrorFrameStyle>
</ValidationSettings>
</dx:ASPxTextBox>
</td>
<td rowspan="4">
<div class="pcmSideSpacer">
</div>
</td>
</tr>
<tr>
<td class="pcmCellCaption" >
<dx:ASPxLabel ID="lblPass1" runat="server" Text="Password:" AssociatedControlID="tbPassword">
</dx:ASPxLabel>
</td>
<td class="pcmCellText">
<dx:ASPxTextBox ID="tbPassword" runat="server" Width="150px" Password="True">
<ValidationSettings EnableCustomValidation="True" ValidationGroup="entryGroup" SetFocusOnError="True"
ErrorDisplayMode="Text" ErrorTextPosition="Bottom">
<RequiredField ErrorText="Password required" IsRequired="True" />
<ErrorFrameStyle Font-Size="10px">
<ErrorTextPaddings PaddingLeft="0px" />
</ErrorFrameStyle>
</ValidationSettings>
</dx:ASPxTextBox>
</td>
</tr>
<tr>
<td>
</td>
<td class="pcmCheckBox">
<dx:ASPxCheckBox ID="chbRemember" runat="server" Text="Remember me">
</dx:ASPxCheckBox>
</td>
</tr>
<tr>
<td colspan="2">
<div class="pcmButton">
<dx:ASPxButton ID="btOK" runat="server" Text="OK" Width="80px" AutoPostBack="False" style="float: left; margin-right: 8px">
<ClientSideEvents Click="function(s, e) { if(ASPxClientEdit.ValidateGroup('entryGroup')) pcLogin.Hide(); }" />
</dx:ASPxButton>
<dx:ASPxButton ID="btCancel" runat="server" Text="Cancel" Width="80px" AutoPostBack="False" style="float: left; margin-right: 8px">
<ClientSideEvents Click="function(s, e) { pcLogin.Hide(); }" />
</dx:ASPxButton>
</div>
</td>
</tr>
</table>
</dx:PanelContent>
</PanelCollection>
</dx:ASPxPanel>
<div>
<a href="javascript:ShowCreateAccountWindow();" id="hl1" style="float: right; margin: 14px 0 10px 0;">
Create Account</a>
</div>
</dx:PopupControlContentControl>
</ContentCollection>
<ContentStyle>
<Paddings PaddingBottom="5px" />
</ContentStyle>
</dx:ASPxPopupControl>
<dx:ASPxPopupControl ID="pcCreateAccount" runat="server" CloseAction="CloseButton"
PopupHorizontalAlign="WindowCenter" PopupVerticalAlign="WindowCenter" ClientInstanceName="pcCreateAccount"
HeaderText="Create Account" AllowDragging="True" Modal="True" PopupAnimationType="Fade"
EnableViewState="False" PopupHorizontalOffset="40" PopupVerticalOffset="40">
<ClientSideEvents PopUp="function(s, e) { ASPxClientEdit.ClearGroup('createAccountGroup'); }" />
<SizeGripImage Width="11px" />
<ContentCollection>
<dx:PopupControlContentControl runat="server">
<dx:ASPxPanel ID="Panel2" runat="server" DefaultButton="btCreate">
<PanelCollection>
<dx:PanelContent runat="server">
<table>
<tr>
<td rowspan="5">
<div class="pcmSideSpacer">
</div>
</td>
<td class="pcmCellCaption" >
<dx:ASPxLabel ID="lblUsername2" runat="server" Text="Username:" AssociatedControlID="tbUsername">
</dx:ASPxLabel>
</td>
<td class="pcmCellText">
<dx:ASPxTextBox ID="tbUsername" runat="server" Width="150px" ClientInstanceName="tbUsername">
<ValidationSettings EnableCustomValidation="True" ValidationGroup="createAccountGroup"
SetFocusOnError="True" ErrorDisplayMode="Text" ErrorTextPosition="Bottom">
<RequiredField IsRequired="True" ErrorText="Username is required" />
<ErrorFrameStyle Font-Size="10px">
<ErrorTextPaddings PaddingLeft="0px" />
</ErrorFrameStyle>
</ValidationSettings>
</dx:ASPxTextBox>
</td>
<td rowspan="5">
<div class="pcmSideSpacer">
</div>
</td>
</tr>
<tr>
<td class="pcmCellCaption" >
<dx:ASPxLabel ID="lblPass2" runat="server" Text="Password:" AssociatedControlID="tbPass1">
</dx:ASPxLabel>
</td>
<td class="pcmCellText">
<dx:ASPxTextBox ID="tbPass1" runat="server" Width="150px" ClientInstanceName="pass1"
Password="True">
<ValidationSettings EnableCustomValidation="True" ValidationGroup="createAccountGroup"
SetFocusOnError="True" ErrorDisplayMode="Text" ErrorTextPosition="Bottom">
<RequiredField IsRequired="True" ErrorText="Password is required" />
<ErrorFrameStyle Font-Size="10px">
<ErrorTextPaddings PaddingLeft="0px" />
</ErrorFrameStyle>
</ValidationSettings>
</dx:ASPxTextBox>
</td>
</tr>
<tr>
<td class="pcmCellCaption" >
<dx:ASPxLabel ID="lblConfPass2" runat="server" Text="Confirm password:" AssociatedControlID="tbConfPass2">
</dx:ASPxLabel>
</td>
<td class="pcmCellText">
<dx:ASPxTextBox ID="tbConfPass2" runat="server" Width="150px" ClientInstanceName="pass2"
Password="True">
<ValidationSettings EnableCustomValidation="True" ValidationGroup="createAccountGroup"
SetFocusOnError="True" ErrorText="Password is incorrect" ErrorDisplayMode="Text"
ErrorTextPosition="Bottom">
<RequiredField IsRequired="True" ErrorText="Please, confirm your password" />
<ErrorFrameStyle Font-Size="10px">
<ErrorTextPaddings PaddingLeft="0px" />
</ErrorFrameStyle>
</ValidationSettings>
<ClientSideEvents Validation="function(s, e) { e.isValid = (pass1.GetText()==pass2.GetText()); }" />
</dx:ASPxTextBox>
</td>
</tr>
<tr>
<td class="pcmCellCaption" >
<dx:ASPxLabel ID="lblEmail" runat="server" Text="Email:" AssociatedControlID="tbEmail">
</dx:ASPxLabel>
</td>
<td class="pcmCellText">
<dx:ASPxTextBox ID="tbEmail" runat="server" Width="150px">
<ValidationSettings EnableCustomValidation="True" ValidationGroup="createAccountGroup"
SetFocusOnError="True" ErrorDisplayMode="Text" ErrorTextPosition="Bottom">
<RequiredField IsRequired="True" ErrorText="E-mail is required" />
<RegularExpression ErrorText="Invalid e-mail" ValidationExpression="w+([-+.']w+)*@w+([-.]w+)*.w+([-.]w+)*" />
<ErrorFrameStyle Font-Size="10px">
<ErrorTextPaddings PaddingLeft="0px" />
</ErrorFrameStyle>
</ValidationSettings>
</dx:ASPxTextBox>
</td>
</tr>
<tr>
<td colspan="2">
<div class="pcmButton">
<dx:ASPxButton ID="btCreate" runat="server" Text="OK" Width="80px" AutoPostBack="False" style="float: left; margin-right: 8px">
<ClientSideEvents Click="function(s, e) {
if(ASPxClientEdit.ValidateGroup('createAccountGroup')) {
ASPxClientEdit.ClearGroup('entryGroup');
tbLogin.SetText(tbUsername.GetText());
pcCreateAccount.Hide();
}
}" />
</dx:ASPxButton>
<dx:ASPxButton ID="btCancel2" runat="server" Text="Cancel" Width="80px" AutoPostBack="False" style="float: left; margin-right: 8px">
<ClientSideEvents Click="function(s, e) { pcCreateAccount.Hide(); }" />
</dx:ASPxButton>
</div>
</td>
</tr>
</table>
</dx:PanelContent>
</PanelCollection>
</dx:ASPxPanel>
</dx:PopupControlContentControl>
</ContentCollection>
</dx:ASPxPopupControl>
</asp:Content>