[求助]媒体播放时怎样控制音量

我爱彩虹

小弟最近在用CB做播放器，基本功能都实现了，就是不能控制音量，还有就是播放窗口不能变大和变小，请高手帮忙看看该怎么办？

ilikenba

在Timer的OnTimer事件中添加代码，要将Enabled属性设成true，才开始执行！

ilikenba

你是将Form2的类包含进去了，应该没有问题！

我爱彩虹

<>我定义了两个窗体:Form1和Form2, 保存为:Unit1.h和Unit2.h,其中Form1是主窗体,Form2是副窗体,我想实现的功能是Form1能够调用Form2,于是我在Form1中添加了Unit2.h,这种样子:</P><>#include &lt;vcl.h&gt;
; t' U" N) f" Y/ {( h7 n" n! `#pragma hdrstop
#include "SoundControl.h"
#include "Unit1.h"//主窗体
+ o0 N4 b$ V8 T" R; m) o#include "Unit2.h"//复窗体</P><>结果运行的时候就要报下面的错误:</P><>[Linker Error] Unresolved external '_playForm' referenced from C:\PROGRAM FILES\BORLAND\CBUILDER6\PROJECTS\主窗口\UNIT1.OBJ</P><>各位大虾,我该怎么修改才能调用Form2啊?</P>[em06]

我爱彩虹

怎么在时间控件里添加代码啊？

ilikenba

<>可以！</P>

小菜菜同学

是不是可以加个时间控件呀，用<b><FONT color=#000066>播放开关控制？</FONT></b>

我爱彩虹

<FONT color=#000066><b>ilikenba大哥，</b><FONT color=#000000>[em01]</FONT><b>在麻烦你哈，我要是想在播放的时候把播放的视频或音频文件的时显示出来，我该怎么办啊？？这几天为了这个我头都搞大了.</b></FONT>

ilikenba

<DIV class=HtmlCode>
<>//---------------------------------------------------------------------------</P>
$ D0 O5 C! [, b<>#ifndef SoundControlH
% o2 [2 u% f. T* A' M#define SoundControlH
//---------------------------------------------------------------------------
#include &lt;Classes.hpp&gt;
$ O- r- O1 z: g/ z0 c3 k  U#include &lt;mmsystem.h&gt;
, K8 Y3 M+ f5 J" N#include &lt;mmreg.h&gt;</P>
<>
bool GetVolumeControl(HMIXER hmixer ,long componentType,long ctrlType,MIXERCONTROL* mxc);</P>
1 q% k8 X2 L3 L( M' A  N<>long GetMuteValue(HMIXER hmixer ,MIXERCONTROL *mxc) ;
unsigned GetVolumeValue(HMIXER hmixer ,MIXERCONTROL *mxc);
bool SetVolumeValue(HMIXER hmixer ,MIXERCONTROL *mxc, long volume);
bool SetMuteValue(HMIXER hmixer ,MIXERCONTROL *mxc, bool mute);</P>
<>
//下面四个是输出函数，可以自己调用
bool WINAPI SetVolume(long dev,long vol);//设置设备的音量
unsigned WINAPI GetVolume(int dev);//得到设备的音量dev=0主音量，1WAVE ,2MIDI ,3 LINE IN</P>
! p+ d1 P$ J' }. ]<>bool WINAPI SetMute(long dev,bool vol);//设置设备静音
bool WINAPI GetMute(long dev);
1 V& ^3 R: D5 e: D#endif</P>
9 C: c. h+ |: g/ V  _8 i
<>bool GetVolumeControl(HMIXER hmixer ,long componentType,long ctrlType,MIXERCONTROL* mxc)
{
6 {1 ~& V/ w; m; p$ |. DMIXERLINECONTROLS mxlc;
MIXERLINE mxl;
& Z) \8 l. e+ o* x& e' ?4 Jmxl.cbStruct = sizeof(mxl);
, `( w- ^5 b1 A; b! c% g/ Ymxl.dwComponentType = componentType;
if(!mixerGetLineInfo((HMIXEROBJ)hmixer, &amp;mxl, MIXER_GETLINEINFOF_COMPONENTTYPE))
5 \3 l, O7 A# U0 P% f9 ?1 K{
3 e: B6 R& a7 z9 R6 M0 S. b: Q5 H& ^mxlc.cbStruct = sizeof(mxlc);
mxlc.dwLineID = mxl.dwLineID;
7 B, I( _7 _( M, j* o; A& emxlc.dwControlType = ctrlType;
mxlc.cControls = 1;
mxlc.cbmxctrl = sizeof(MIXERCONTROL);
mxlc.pamxctrl = mxc;
- o2 O  Y* F% `5 }# D# [if(mixerGetLineControls((HMIXEROBJ)hmixer,&amp;mxlc,MIXER_GETLINECONTROLSF_ONEBYTYPE))
return 0;
else
* K* _4 s7 ~+ u5 f* ?return 1;
$ m. w$ y' D: q5 \2 V) I0 ^- I}
3 y* K' @+ ~  n( ireturn 0;
}
' Z$ w5 @3 b' M" k3 v- ^//---------------------------------------------------------------------------
  t/ s  Y6 `/ m2 {/ r! |long GetMuteValue(HMIXER hmixer ,MIXERCONTROL *mxc)
{
9 t9 u" i+ W3 y6 ]1 ^0 h/ ?6 Q( AMIXERCONTROLDETAILS mxcd;
  \1 ?# d8 J& A" e, ]0 Q7 HMIXERCONTROLDETAILS_BOOLEAN mxcdMute;
) b# U4 w8 H9 C0 m. `  cmxcd.hwndOwner = 0;
mxcd.cbStruct = sizeof(mxcd);
mxcd.dwControlID = mxc-&gt;dwControlID;
1 H3 n* ^* D& I9 E$ ^mxcd.cbDetails = sizeof(mxcdMute);
mxcd.paDetails = &amp;mxcdMute;
mxcd.cChannels = 1;
mxcd.cMultipleItems = 0;
  o5 g! ~+ E, A( J- J7 d. aif (mixerGetControlDetails((HMIXEROBJ)hmixer, &amp;mxcd,MIXER_OBJECTF_HMIXER|MIXER_GETCONTROLDETAILSF_VALUE))
return -1;
- E! {0 B; v# X0 d% O5 S6 Zreturn mxcdMute.fValue;
3 d9 e/ v0 c" S% l$ U8 q} </P>
0 b9 C% S6 X8 a1 c/ z8 {4 t  v<>//---------------------------------------------------------------------------
unsigned GetVolumeValue(HMIXER hmixer ,MIXERCONTROL *mxc)
{
4 U1 H/ T3 z6 D4 d" b0 _" J0 CMIXERCONTROLDETAILS mxcd;
  E: Q7 e/ X* r  ]$ R3 jMIXERCONTROLDETAILS_UNSIGNED vol; vol.dwValue=0;
- Z" M) C- j/ A2 n; _) z, bmxcd.hwndOwner = 0;
% f1 K7 k3 C: rmxcd.cbStruct = sizeof(mxcd);
mxcd.dwControlID = mxc-&gt;dwControlID;
1 G" ~% H# U' Ymxcd.cbDetails = sizeof(vol);
; L" _. J! x0 i: Emxcd.paDetails = &amp;vol;
mxcd.cChannels = 1;
if(mixerGetControlDetails((HMIXEROBJ)hmixer, &amp;mxcd, MIXER_OBJECTF_HMIXER|MIXER_GETCONTROLDETAILSF_VALUE))
return -1;
return vol.dwValue;
/ V1 o5 b: Q3 H} </P>
6 u/ [1 L) k" z6 m. q. V$ O/ r<>//---------------------------------------------------------------------------
bool SetMuteValue(HMIXER hmixer ,MIXERCONTROL *mxc, bool mute)
{
8 V7 u+ g1 I' A  w) K5 ~. XMIXERCONTROLDETAILS mxcd;
, i0 v$ N5 }& [8 R5 hMIXERCONTROLDETAILS_BOOLEAN mxcdMute;mxcdMute.fValue=mute;
" E" m$ Y) h) x7 B% tmxcd.hwndOwner = 0;
* {+ N5 z/ C3 ^mxcd.dwControlID = mxc-&gt;dwControlID;
mxcd.cbStruct = sizeof(mxcd);
" O( i" c  S/ x- p. D6 amxcd.cbDetails = sizeof(mxcdMute);
mxcd.paDetails = &amp;mxcdMute;
mxcd.cChannels = 1;
mxcd.cMultipleItems = 0;
$ U+ _  Y* ?0 ?& ]+ Aif (mixerSetControlDetails((HMIXEROBJ)hmixer, &amp;mxcd, MIXER_OBJECTF_HMIXER|MIXER_SETCONTROLDETAILSF_VALUE))
) n) s% i' q$ a+ @& R3 preturn 0;
: I& o& f2 W( g3 Y2 V9 E# L. [return 1;
- u6 A) }: }4 h+ X# \} </P>
( i& v6 G/ T3 H  Q& K6 d4 i6 A<>//---------------------------------------------------------------------------</P>
<>bool SetVolumeValue(HMIXER hmixer ,MIXERCONTROL *mxc, long volume)
/ O) ~, c/ a: q- Z2 r% @{
' E, Y( F7 k, `" L* d9 K/ VMIXERCONTROLDETAILS mxcd;
, h1 y  s' I$ QMIXERCONTROLDETAILS_UNSIGNED vol;vol.dwValue = volume;
mxcd.hwndOwner = 0;
mxcd.dwControlID = mxc-&gt;dwControlID;
mxcd.cbStruct = sizeof(mxcd);
mxcd.cbDetails = sizeof(vol);
' I# q5 U/ a1 L/ z! Imxcd.paDetails = &amp;vol;
" N  O- G; g* i8 q/ C: H/ Emxcd.cChannels = 1;
) w  W6 h2 r, _$ s& c, M/ N: l3 H9 ^if(mixerSetControlDetails((HMIXEROBJ)hmixer, &amp;mxcd, MIXER_OBJECTF_HMIXER|MIXER_SETCONTROLDETAILSF_VALUE))
return 0;
return 1;
& Z0 ^0 Z5 _. Y4 F) C  i} </P>
# m5 n2 U4 A: [/ n6 @  a4 Y+ f<>
2 \) R) U6 T% D; X1 Z( y, ~//---------------------------------------------------------------------------
) ^' a3 _+ q2 p" |. Z/ k; D5 kunsigned WINAPI GetVolume(int dev)//得到设备的音量dev=0主音量，1WAVE ,2MIDI ,3 LINE IN
{</P>
. H3 W0 p! J4 T' V<>long device;unsigned rt=0;
( J! F) \9 ?2 b% {) J7 P% EMIXERCONTROL volCtrl;
6 f: r& M& N+ w4 `& h" {# s' p# ^( ^HMIXER hmixer;
switch (dev)
: `) G, Y& ^! o: p{
case 1:
: p* C' \+ H; e  `  b/ jdevice=MIXERLINE_COMPONENTTYPE_SRC_WAVEOUT; break;
: S2 A* h( ~# k) e% Pcase 2:
* D8 D( ~6 s0 d& B* k0 Y% @) ddevice=MIXERLINE_COMPONENTTYPE_SRC_SYNTHESIZER; break;
; W( F7 c  O( k3 P' f0 B: V7 ocase 3:
  O" M" y0 Q6 i& P// device=MIXERLINE_COMPONENTTYPE_SRC_COMPACTDISC; break; // cd 音量
// device=MIXERLINE_COMPONENTTYPE_SRC_MICROPHONE; break; //麦克风音量
1 C6 T$ R7 n0 W" n// device=MIXERLINE_COMPONENTTYPE_SRC_LINE; break; //PC 扬声器音量
  a+ n7 M* g% }. d7 ndevice=MIXERLINE_COMPONENTTYPE_SRC_COMPACTDISC; break; </P>
1 R! I' E' G* a$ A<>default:
, t  H3 q* T% hdevice=MIXERLINE_COMPONENTTYPE_DST_SPEAKERS;
0 }5 Q0 ~$ x+ h}</P>
- m3 v$ U5 p4 W0 {/ j$ P/ C5 \<>if(mixerOpen(&amp;hmixer, 0, 0, 0, 0)) return 0;
if(!GetVolumeControl(hmixer,device,MIXERCONTROL_CONTROLTYPE_VOLUME,&amp;volCtrl))
/ W# \6 R5 n4 ]/ Zreturn 0;
rt=GetVolumeValue(hmixer,&amp;volCtrl)*100/volCtrl.Bounds.lMaximum;
mixerClose(hmixer);
3 T+ f4 d- ~3 B: _' _$ @return rt;</P>
<>}</P>
<>//---------------------------------------------------------------------------</P>
0 t3 N, t( R" V  a, x7 j5 s' `<>bool WINAPI SetVolume(long dev,long vol)//设置设备的音量
4 ^# y7 H6 v3 [/ U: e$ I{
// dev =0,1,2 分别表示主音量,波形,MIDI ,LINE IN
8 I& F) [$ x) Y+ f2 x// vol=0-100 表示音量的大小 , 设置与返回音量的值用的是百分比，即音量从0 - 100，而不是设备的绝对值
. s$ H% B; K& J( A7 V6 o  [6 X// retrun false 表示设置音量的大小的操作不成功
# t+ y3 T% `/ `+ `3 M// retrun true 表示设置音量的大小的操作成功</P>
<>long device;
! i7 ^, V5 u1 z% ]/ Lbool rc=false;
MIXERCONTROL volCtrl;
1 E2 ~9 v; n3 r+ w# NHMIXER hmixer;
: A7 |: _# `7 `* |  Gswitch (dev)
* M& g+ U  v6 q2 l  e{
case 1:
9 K3 ~, [' U9 X8 y9 G! ldevice=MIXERLINE_COMPONENTTYPE_SRC_WAVEOUT; break;
% T: B4 d: t5 i- f6 P$ {/ `' r7 Xcase 2:
+ X/ ?) E1 z' p# N; B( Tdevice=MIXERLINE_COMPONENTTYPE_SRC_SYNTHESIZER; break;
case 3:
device=MIXERLINE_COMPONENTTYPE_SRC_COMPACTDISC; break;</P>
) q3 j6 e# u, U! D% B<>default:
5 E/ E5 f9 _/ G- Cdevice=MIXERLINE_COMPONENTTYPE_DST_SPEAKERS;
% ^" X& v' t$ B* A! V; O% b4 t. q} </P>
<>if(mixerOpen(&amp;hmixer, 0, 0, 0, 0)) return 0;</P>
<>if(GetVolumeControl(hmixer,device,MIXERCONTROL_CONTROLTYPE_VOLUME,&amp;volCtrl))
{
" G, [, \$ i5 a* n, Y3 Bvol=vol*volCtrl.Bounds.lMaximum/100;
# n& b$ L9 M( ^if(SetVolumeValue(hmixer,&amp;volCtrl,vol))
rc=true;
}
0 Z7 n- \: s5 ~# w8 P  _" ZmixerClose(hmixer);
return rc;
} </P>
<>//---------------------------------------------------------------------------</P>
( T* O4 J' C) m5 F8 f: Q6 a1 ?& o<>bool WINAPI SetMute(long dev,bool vol)//设置设备静音
{
// dev =0,1,2 分别表示主音量,波形,MIDI ,LINE IN
// vol=0,1 分别表示取消静音,设置静音
// retrun false 表示取消或设置静音操作不成功
// retrun true 表示取消或设置静音操作成功</P>
<>long device;
bool rc=false;
) ?: U, d$ t' V+ n( HMIXERCONTROL volCtrl;
6 k  V" i9 ?+ Y' B/ c  JHMIXER hmixer;
switch (dev)
5 @( b9 C' }: @9 J# l# X: N& \{
( o. O2 F7 [( }9 e* C, W2 q5 ycase 1:
device=MIXERLINE_COMPONENTTYPE_SRC_WAVEOUT; break;
2 [. S* W; ~+ M- K" ^2 Wcase 2:
device=MIXERLINE_COMPONENTTYPE_SRC_SYNTHESIZER; break;
* u! f4 {& g) o% L+ v! C7 _case 3:
device=MIXERLINE_COMPONENTTYPE_SRC_COMPACTDISC; break; </P>
: ]. L& a2 C$ v" v& A' N<>default:
device=MIXERLINE_COMPONENTTYPE_DST_SPEAKERS;
} </P>
<>if(mixerOpen(&amp;hmixer, 0, 0, 0, 0)) return 0;
1 _9 p# x4 u' f! a& Jif(GetVolumeControl(hmixer,device,MIXERCONTROL_CONTROLTYPE_MUTE,&amp;volCtrl))
5 G, O: U- C* ]9 J: G6 x* V4 P/ P' [if(SetMuteValue(hmixer,&amp;volCtrl,(bool)vol))
8 E/ _7 a) I. W  R' f0 lrc=true;
* @6 A# }9 G* u3 i$ s% A- LmixerClose(hmixer);
+ j3 O4 Y0 r' [. ireturn rc;
} </P>
<>//---------------------------------------------------------------------------</P>
<>bool WINAPI GetMute(long dev)//检查设备是否静音
  U* [; X! l2 ~! x0 f( @, C- E{
% Y0 h. T8 I% W9 R" N  X  `//dev =0,1,2 分别表示主音量，波形,MIDI ,LINE IN
// retrun false 表示没有静音
5 f' N" @8 `/ x! h// retrun true 表示静音
( x% B/ L) ^8 h( j/ Rlong device;
bool rc=false;
8 ^  W% t- q9 x, j8 uMIXERCONTROL volCtrl;
HMIXER hmixer;
switch (dev)
; c8 [: y. U* y/ ?. e- t{
case 1:
device=MIXERLINE_COMPONENTTYPE_SRC_WAVEOUT; break;
* @8 n+ p# _/ Z6 {# G2 y8 c" icase 2:
device=MIXERLINE_COMPONENTTYPE_SRC_SYNTHESIZER; break;
case 3:
$ C- v( A6 D4 ]7 U6 o/ K  O& kdevice=MIXERLINE_COMPONENTTYPE_SRC_COMPACTDISC; break;
2 X0 z5 g* ^" X& g8 u4 G' J! @default:
2 ]! x" r  V, p% P- Ddevice=MIXERLINE_COMPONENTTYPE_DST_SPEAKERS;
+ P4 m% k5 t- F. G, \& b( l$ h} </P>
<>if(mixerOpen(&amp;hmixer, 0, 0, 0, 0)) return 0; </P>
- D2 Z' I& H( @% E. q. d( f! T<P>if(GetVolumeControl(hmixer,device,MIXERCONTROL_CONTROLTYPE_MUTE,&amp;volCtrl))
rc=GetMuteValue(hmixer,&amp;volCtrl);
3 _3 m  g  C; MmixerClose(hmixer);
/ s: L6 f- U8 x; G4 z$ _return rc;</P>
<P>}</P></DIV>
- {5 L$ B0 ]: q: K% ^' b<P><b><EM><FONT style="BACKGROUND-COLOR: #fdfddf" face=Tahoma>上面的存为SoundControl.h</FONT></EM></b></P>
<DIV class=HtmlCode>
$ `- p2 c: F# e5 J& Q2 f<P>#include &lt;vcl.h&gt;
#pragma hdrstop
#include "SoundControl.h"
& q1 y. [" F4 x% A' _#include "Unit1.h"
//---------------------------------------------------------------------------
& I& _) S; [8 b6 f#pragma package(smart_init)
#pragma resource "*.dfm"
' ^6 z, j2 t3 u* E* ^# q' ~, w* JTForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
) r: ~4 ~* j: b' \- b- _        : TForm(Owner)
{</P>
<P>}</P>
+ i' f7 N2 m6 ~; n<P>void __fastcall TForm1::CheckBox1Click(TObject *Sender)
" ?/ u) \. z. i$ t; e3 t{
  T* _6 c' b# C9 cSetMute(0,CheckBox1-&gt;Checked);
}
2 l& z5 V( Q: ~& A; \# Z//---------------------------------------------------------------------------
/ K4 p- \+ F. b" vvoid __fastcall TForm1::TrackBar1Change(TObject *Sender)
. v6 `8 f% y7 Z& X" f# t{
# M6 O8 ^" i5 K2 C- A     SetVolume(0,TrackBar1-&gt;Position);
+ r: U' h% Q, o: x}
. S, K, c' r: w3 L8 Hvoid __fastcall TForm1::Button1Click(TObject *Sender)
2 [" Q' U9 s/ R: n! ]{
   TrackBar1-&gt;Position = GetVolume(1);
}
  g( K$ @2 p% S( }: Dvoid __fastcall TForm1::Button3Click(TObject *Sender)
0 y2 C; V5 j9 _; t# }{
    CheckBox1-&gt;Checked=  GetMute(0);
7 V, }2 E0 e! e}</P></DIV>