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   <TITLE>Start a program so it obeys the <TT>nCmdShow</TT> argument (passed by a shortcut)</TITLE>

   <META NAME="Author" CONTENT="Harold Howe">

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<H3>

Start a program so it obeys the <TT>nCmdShow</TT> argument (passed by a shortcut)

</H3>



<P>

<I>This entire FAQ applies only to C++Builder 1.0. Programs written in C++Builder 1.0 would not obey the

<TT>nCmdShow</TT> argument that was passed to <TT>WinMain</TT>. C++Builder 3.0 fixed this problem. If you

use C++Builder 3.0 or newer, this FAQ should be ignored.</I></P>

<P>

This is an extenstion to the

<A HREF="faq5.htm">"Starting a program minimized"</A>

FAQ. The infamous line in SYSTEM.PAS causes VCL programs to

ignore the <TT>nCmdShow</TT> parameter that is passed to the program. One impact of

this is that the user will not be able to choose how to start a program

(minimized, maximized, etc) using shortcuts. Plus, a VCL app that is

started by the registry Run key or by a line in WIN.INI will be passed

an <TT>nCmdShow</TT> value of <TT>SW_SHOWMINNOACTIVATE</TT>. Because the VCL ignores the

<TT>nCmdShow</TT> value, C++Builder programs will not conform to the OS requests. You can

fix this problem by calling an API function to determine the original <TT>nCmdShow</TT> value,

and placing the program in its proper state based on the value.

</P>

<P>

<B>Step 1:</B> Choose View|Project Source from the C++Builder menu so you

can edit the <TT>WinMain</TT> function. Call the API <TT>GetStartupInfo</TT>

function to determine the original nCmdShow value. Then react based on

the value.

</P>

<pre>

WINAPI WinMain<b>(</b>HINSTANCE<b>,</b> HINSTANCE<b>,</b> LPSTR<b>,</b> <b>int</b><b>)</b>

<b>{</b>

    <b>int</b> MyCmdShow <b>=</b> SW_SHOWDEFAULT<b>;</b>

    STARTUPINFO StartupInfo<b>;</b>

    GetStartupInfo<b>(</b><b>&</b>StartupInfo<b>)</b><b>;</b>

    <b>if</b><b>(</b>StartupInfo<b>.</b>dwFlags <b>&</b> STARTF_USESHOWWINDOW<b>)</b>

        MyCmdShow <b>=</b> StartupInfo<b>.</b>wShowWindow<b>;</b>



    <b>try</b>

    <b>{</b>

        Application<b>-></b>Initialize<b>(</b><b>)</b><b>;</b>

        Application<b>-></b>CreateForm<b>(</b><b>__classid</b><b>(</b>TForm1<b>)</b><b>,</b> <b>&</b>Form1<b>)</b><b>;</b>



        <b>switch</b><b>(</b>MyCmdShow<b>)</b>

        <b>{</b>

        <b>case</b> SW_SHOWMINNOACTIVE<b>:</b>   <font color="navy">// 7, this is what came from the shortcut</font>

        <b>case</b> SW_MINIMIZE<b>:</b>          <font color="navy">// 6</font>

        <b>case</b> SW_SHOWMINIMIZED<b>:</b>     <font color="navy">// 2</font>

            Application<b>-></b>ShowMainForm <b>=</b> <b>false</b><b>;</b>

            Application<b>-></b>Minimize<b>(</b><b>)</b><b>;</b>

            <b>break</b><b>;</b>

        <b>case</b> SW_SHOWMAXIMIZED<b>:</b>    <font color="navy">// SW_SHOWMAXIMIZED and SW_MAXIMIZE are</font>

        <b>case</b> SW_MAXIMIZE<b>:</b>         <font color="navy">// same value now. Used to be different</font>

            Application<b>-></b>MainForm<b>-></b>WindowState <b>=</b> wsMaximized<b>;</b>

            <b>break</b><b>;</b>

        <b>case</b> SW_HIDE<b>:</b>

            Application<b>-></b>ShowMainForm <b>=</b> <b>false</b><b>;</b>

            ShowWindow<b>(</b>Application<b>-></b>Handle<b>,</b> SW_HIDE<b>)</b><b>;</b>

            <b>break</b><b>;</b>

        <b>default</b><b>:</b>

            Application<b>-></b>MainForm<b>-></b>WindowState <b>=</b> wsNormal<b>;</b>

        <b>}</b>



        Application<b>-></b>Run<b>(</b><b>)</b><b>;</b>

    <b>}</b>

    <b>catch</b> <b>(</b>Exception <b>&</b>exception<b>)</b>

    <b>{</b>

        Application<b>-></b>ShowException<b>(</b><b>&</b>exception<b>)</b><b>;</b>

    <b>}</b>

    <b>return</b> <font color="blue">0</font><b>;</b>

<b>}</b>



</pre>



<P>

<B>Step 2:</B> Setting <TT>ShowMainForm</TT> to <TT>false</TT> has one bad

side effect. The form will not appear when the user restores the program by

clicking on the taskbar icon. You can solve this problem by creating an

<TT>OnRestore</TT> handler for the application. Open the header file for the

main form and add this prototype to your main form's class.

</P>

<PRE>

<B>private:</B>	// User declarations

  <B>void __fastcall</B> AppRestore(TObject *Sender);

</PRE>



<P>

<B>Step 3:</B> Open the main form's CPP file and code the 

<TT>AppRestore</TT> function.

</P>

<PRE>

<B>void __fastcall</B> TForm1::AppRestore(TObject *Sender)

{

  Visible = <B>true</B>;

}

</PRE>



<P>

<B>Step 4:</B> Assign the <TT>AppRestore</TT> function to the 

<TT>OnRestore</TT> handler of <TT>TApplication</TT>. Make this assignment 

in the constructor of the main form.

</P>

<PRE>

<B>__fastcall</B> TForm1::TForm1(TComponent* Owner)

	: TForm(Owner)

{

  Application-&gt;OnRestore = AppRestore;

}

</PRE>

<P>

<B>Final Note:</B> The code works find except for one small glitch. The

taskbar icon for the program should not be selected when the program is

started with <TT>nCmdShow</TT> set to <TT>SW_SHOWMINNOACTIVATE</TT>. The 

<TT>TApplication::CreateHandle</TT> function contains code that creates 

the taskbar icon, and because of the way Windows works, focuses the 

newly created icon. By the time <TT>WinMain</TT> executes, its too late to 

respond to <TT>nCmdShow</TT> without activating the icon.

</P>





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