📄 func1_0d6b.htm
字号:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<HTML DIR="LTR"><HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso8859-1">
</HEAD>
<TITLE>lineGetNumRings</TITLE>
<SCRIPT SRC="/library/psdk/linkcss.js"></SCRIPT>
<META NAME="MS-HKWD" CONTENT="lineGetNumRings">
<META NAME="MS-HAID" CONTENT="_tapi2_linegetnumrings">
</HEAD>
<BODY TOPMARGIN="0">
<!--TOOLBAR_START-->
<!--TOOLBAR_EXEMPT-->
<!--TOOLBAR_END-->
<!--SYNC_START-->
<script language="JavaScript" src='/library/synch.js'></script>
<!--SYNC_END-->
<H1><A NAME="_tapi2_linegetnumrings"></A>lineGetNumRings</H1>
<P>The <B>lineGetNumRings</B> function determines the number of rings an incoming call on the given address should ring prior to answering the call. </P>
<PRE class=syntax><B>LONG WINAPI lineGetNumRings(
HLINE</B><I> hLine</I><B>, </B>
<B> DWORD</B><I> dwAddressID</I><B>, </B>
<B> LPDWORD</B><I> lpdwNumRings </I>
<B>);</B></PRE>
<H4>Parameters</H4>
<DL>
<DT><I>hLine</I> </DT>
<DD>A handle to the open line device. </DD>
<DT><I>dwAddressID</I> </DT>
<DD>An address on the line device. An address identifier is permanently associated with an address; the identifier remains constant across operating system upgrades.</DD>
<DT><I>lpdwNumRings</I> </DT>
<DD>The number of rings that is the minimum of all current <A HREF="func2_7prn.htm" tppabs="http://msdn.microsoft.com/library/psdk/tapi22/func2_7prn.htm"><B>lineSetNumRings</B></A> requests.
</DD>
</DL>
<H4>Return Values</H4>
<P>Returns zero if the request succeeds or a negative error number if an error occurs. Possible return values are: </P>
<P>LINEERR_INVALADDRESSID, LINEERR_OPERATIONFAILED, LINEERR_INVALLINEHANDLE, LINEERR_RESOURCEUNAVAIL, LINEERR_INVALPOINTER, LINEERR_UNINITIALIZED, LINEERR_NOMEM. </P>
<H4>Remarks</H4>
<P>The <B>lineGetNumRings</B> and <A HREF="func2_7prn.htm" tppabs="http://msdn.microsoft.com/library/psdk/tapi22/func2_7prn.htm"><B>lineSetNumRings</B></A> functions, when used in combination, provide a mechanism to support the implementation of toll-saver features across multiple independent applications. </P>
<P>An application that receives a handle for a call in the <I>offering</I> state and a <A HREF="msgs_402t.htm" tppabs="http://msdn.microsoft.com/library/psdk/tapi22/msgs_402t.htm">LINE_LINEDEVSTATE</A> <I>ringing</I> message should wait a number of rings equal to the number returned by <B>lineGetNumRings</B> before answering the call in order to honor the toll-saver settings across all applications. The <B>lineGetNumRings</B> function returns the minimum of all applications' number of rings specified by <B>lineSetNumRings</B>. Because this number can vary dynamically, an application should invoke <B>lineGetNumRings</B> each time it has the option to answer a call. If no application has called <A HREF="func2_7prn.htm" tppabs="http://msdn.microsoft.com/library/psdk/tapi22/func2_7prn.htm"><B>lineSetNumRings</B></A>, the number of rings returned is 0xFFFFFFFF. A separate LINE_LINEDEVSTATE <I>ringing</I> message is sent to the application for each ring cycle. </P>
<P>If call classification is performed by TAPI of answering all calls of unknown media mode and filtering the media stream, TAPI honors this number as well. </P>
<P><B>Note</B> This operation is purely informational and does not in itself affect the state of any calls on the line device. </P>
<H4><A HREF="javascript:if(confirm('http://msdn.microsoft.com/library/psdk/sdkintro/guide_927n.htm \n\n这个文件不能通过 Teleport Pro 取回, 因为 地址在一个域或为它的开始地址设定的边界的外部路径上. \n\n你想从服务器打开它吗?'))window.location='http://msdn.microsoft.com/library/psdk/sdkintro/guide_927n.htm'" tppabs="http://msdn.microsoft.com/library/psdk/sdkintro/guide_927n.htm">Requirements</A> </H4>
<P><B> Windows NT/2000: </B>Requires Windows NT 4.0 SP3 or later.<BR>
<B> Windows 95/98: </B>Requires Windows 95 or later.<BR>
<B> Version: </B>Requires TAPI 1.3 or later.<BR>
<B> Header: </B>Declared in Tapi.h.<BR>
<B> Library: </B>Use Tapi32.lib.</P>
<H4>See Also</H4>
<P><A HREF="quickref_1okl.htm" tppabs="http://msdn.microsoft.com/library/psdk/tapi22/quickref_1okl.htm">TAPI 2.2 Reference Overview</A>, <A HREF="quickref_1pnp.htm" tppabs="http://msdn.microsoft.com/library/psdk/tapi22/quickref_1pnp.htm">Basic Telephony Services Reference</A>, <A HREF="msgs_402t.htm" tppabs="http://msdn.microsoft.com/library/psdk/tapi22/msgs_402t.htm">LINE_LINEDEVSTATE</A>, <A HREF="func2_7prn.htm" tppabs="http://msdn.microsoft.com/library/psdk/tapi22/func2_7prn.htm"><B>lineSetNumRings</B></A></P>
<DIV CLASS="footer">Built on Monday, August 14, 2000</DIV>
<!--FOOTER_START-->
<DIV CLASS="footer" STYLE="color:#000000;font-size:90%;">
<A HREF="mailto:sdkfdbk@microsoft.com">Send feedback</A> to the Platform SDK.</P>
<P><A HREF="javascript:if(confirm('http://msdn.microsoft.com/isapi/gomscom.asp?TARGET=/info/cpyright.htm \n\n这个文件不能通过 Teleport Pro 取回, 因为 地址在一个域或为它的开始地址设定的边界的外部路径上. \n\n你想从服务器打开它吗?'))window.location='http://msdn.microsoft.com/isapi/gomscom.asp?TARGET=/info/cpyright.htm'" tppabs="http://msdn.microsoft.com/isapi/gomscom.asp?TARGET=/info/cpyright.htm" TARGET="_top">© 1999 Microsoft Corporation. All rights reserved. Terms of use.</A></P>
</DIV>
<!--FOOTER_END-->
</BODY>
</HTML>
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -