📄 0,1410,26545,00.html

📁 C++builder学习资料C++builder
💻 HTML
📖 第 1 页 / 共 2 页
字号:
上一页 12
                      DWORD grfKeyState, _POINTL pt, DWORD *pdwEffect);

  HRESULT <b>__stdcall</b> DragOver(DWORD grfKeyState, _POINTL pt,

                      DWORD *pdwEffect);

  HRESULT <b>__stdcall</b> DragLeave();

  HRESULT <b>__stdcall</b> Drop(IDataObject *pDataObject, DWORD grfKeyState,

                      _POINTL pt, DWORD *pdwEffect);

};

<font color="#0000AA"><i>//---------------------------------------------------------------------------</i></font>

<font color="202020">#endif</font>

</code></pre> 

</td></tr> 

</table> 

 

<p><table border=1 width=90% cellpadding=3 cellspacing=0> 

<tr bgcolor=blue><td><font color=white>GenericVCLDropTarget.cpp</font></td></tr> 

<tr><td> 

<pre><code>

<font color="#0000AA"><i>//---------------------------------------------------------------------------</i></font>



<font color="202020">#include &lt;vcl.h&gt;</font>

<font color="202020">#pragma hdrstop</font>



<font color="202020">#include &quot;GenericVCLDropTarget.h&quot;</font>

<font color="202020">#pragma package(smart_init)</font>



<font color="#0000AA"><i>//---------------------------------------------------------------------------</i></font>

<b>__fastcall</b> TGenericVCLDropTarget::TGenericVCLDropTarget(TComponent* Owner)

  : TComponent(Owner)

{

  registered = <b>false</b>;

  m_DropTarget = NULL;

  OleInitialize(NULL);

  m_dt = <b>new</b> TDropTargetImpl(<b>this</b>);

}

<font color="#0000AA"><i>//---------------------------------------------------------------------------</i></font>

<b>__fastcall</b> TGenericVCLDropTarget::~TGenericVCLDropTarget()

{

  m_dt-&gt;Release();

  <font color="#0000AA"><i>//delete m_dt;</i></font>

  OleUninitialize();

}

<font color="#0000AA"><i>//---------------------------------------------------------------------------</i></font>

<b>void</b> <b>__fastcall</b> TGenericVCLDropTarget::SetDropTarget(TWinControl *target)

{

  <b>if</b> (!ComponentState.Contains(csDesigning))

  {

    <b>if</b> (registered &amp;&amp; m_DropTarget)

      RevokeDragDrop(m_DropTarget-&gt;Handle);

    m_DropTarget = target;

    <b>try</b> {

      RegisterDragDrop(m_DropTarget-&gt;Handle,m_dt);

      registered = true;

    }

    <b>catch</b> (...)

    {

      registered = <b>false</b>;

    }

  }

  <b>else</b>

    m_DropTarget = target;

}

<font color="#0000AA"><i>//---------------------------------------------------------------------------</i></font>

<font color="#0000AA"><i>//---------------------------------------------------------------------------</i></font>



HRESULT <b>__stdcall</b> TDropTargetImpl::QueryInterface(REFIID riid, <b>void</b> **ppv)

{

  <b>if</b> (IsEqualIID(riid,IID_IUnknown))

  {

    *ppv = <b>static_cast</b>&lt;IUnknown *&gt;(<b>this</b>);

    <b>return</b> S_OK;

  }

  <b>else</b> <b>if</b> (IsEqualIID(riid,IID_IDropTarget))

  {

    *ppv = <b>static_cast</b>&lt;IDropTarget *&gt;(<b>this</b>);

    <b>return</b> S_OK;

  }

  <b>else</b>

  {

    *ppv = NULL;

    <b>return</b> E_NOINTERFACE;

  }

}

HRESULT <b>__stdcall</b> TDropTargetImpl::DragEnter(IDataObject *pDataObject,

                      DWORD grfKeyState, _POINTL pt, DWORD *pdwEffect)

{

  <b>return</b> backptr-&gt;DragEnter(pDataObject,grfKeyState,pt,pdwEffect);

}

HRESULT <b>__stdcall</b> TDropTargetImpl::DragOver(DWORD grfKeyState, _POINTL pt,

                    DWORD *pdwEffect)

{

  <b>return</b> backptr-&gt;DragOver(grfKeyState,pt,pdwEffect);

}

HRESULT <b>__stdcall</b> TDropTargetImpl::DragLeave()

{

  <b>return</b> backptr-&gt;DragLeave();

}

HRESULT <b>__stdcall</b> TDropTargetImpl::Drop(IDataObject *pDataObject, DWORD grfKeyState,

                    _POINTL pt, DWORD *pdwEffect)

{

  <b>return</b> backptr-&gt;Drop(pDataObject,grfKeyState,pt,pdwEffect);

}

</code></pre> 

 

</td></tr> 

</table> 

 

<p><table border=1 width=90% cellpadding=3 cellspacing=0> 

<tr bgcolor=blue><td><font color=white>TextDropTarget.h</font></td></tr> 

<tr><td> 

<pre><code>

<font color="#0000AA"><i>//---------------------------------------------------------------------------</i></font>



<font color="202020">#ifndef TextDropTargetH</font>

<font color="202020">#define TextDropTargetH</font>

<font color="#0000AA"><i>//---------------------------------------------------------------------------</i></font>

<font color="202020">#include &lt;SysUtils.hpp&gt;</font>

<font color="202020">#include &lt;Controls.hpp&gt;</font>

<font color="202020">#include &lt;Classes.hpp&gt;</font>

<font color="202020">#include &lt;Forms.hpp&gt;</font>

<font color="202020">#include &quot;GenericVCLDropTarget.h&quot;</font>

<font color="#0000AA"><i>//---------------------------------------------------------------------------</i></font>

<b>typedef</b> <b>void</b> <b>__fastcall</b> (<b>__closure</b> *TDragEvent)

      (TObject *Sender, <b>int</b> x, <b>int</b> y, TShiftState Shift );

<b>typedef</b> <b>void</b> <b>__fastcall</b> (<b>__closure</b> *TDropEvent)

      (TObject *Sender, <b>int</b> x, <b>int</b> y, TShiftState Shift, AnsiString DropText);



<b>class</b> PACKAGE TTextDropTarget : <b>public</b> TGenericVCLDropTarget

{

<b>private</b>:

  TDragEvent FOnDragEnter;

  TDragEvent FOnDragOver;

  TNotifyEvent FOnDragLeave;

  TDropEvent FOnDrop;

<b>protected</b>:

  HRESULT <b>__stdcall</b> DragEnter(IDataObject *pDataObject,

                      DWORD grfKeyState, _POINTL pt, DWORD *pdwEffect);

  HRESULT <b>__stdcall</b> DragOver(DWORD grfKeyState, _POINTL pt,

                      DWORD *pdwEffect);

  HRESULT <b>__stdcall</b> DragLeave();

  HRESULT <b>__stdcall</b> Drop(IDataObject *pDataObject, DWORD grfKeyState,

                      _POINTL pt, DWORD *pdwEffect);

<b>public</b>:

  <b>__fastcall</b> TTextDropTarget(TComponent* Owner);

<b>__published</b>:

  <b>__property</b> TDragEvent OnDragEnter = {read=FOnDragEnter, write=FOnDragEnter};

  <b>__property</b> TDragEvent OnDragOver = {read=FOnDragOver, write=FOnDragOver};

  <b>__property</b> TNotifyEvent OnDragLeave = {read=FOnDragLeave, write=FOnDragLeave};

  <b>__property</b> TDropEvent OnDrop = {read=FOnDrop, write=FOnDrop};

  <b>__property</b> TargetControl;

  <b>__property</b> Registered;

};

<font color="#0000AA"><i>//---------------------------------------------------------------------------</i></font>

<font color="202020">#endif</font>

</code></pre> 

</td></tr> 

</table> 

 

<p><table border=1 width=90% cellpadding=3 cellspacing=0> 

<tr bgcolor=blue><td><font color=white>TextDropTarget.cpp</font></td></tr> 

<tr><td> 

<pre><code>

<font color="#0000AA"><i>//---------------------------------------------------------------------------</i></font>



<font color="202020">#include &lt;vcl.h&gt;</font>

<font color="202020">#pragma hdrstop</font>



<font color="202020">#include &quot;TextDropTarget.h&quot;</font>

<font color="202020">#pragma package(smart_init)</font>

<font color="#0000AA"><i>//---------------------------------------------------------------------------</i></font>

<font color="#0000AA"><i>// ValidCtrCheck is used to assure that the components created do not have</i></font>

<font color="#0000AA"><i>// any pure virtual functions.</i></font>

<font color="#0000AA"><i>//</i></font>



static <b>inline</b> <b>void</b> ValidCtrCheck(TTextDropTarget *)

{

  <b>new</b> TTextDropTarget(NULL);

}

<font color="#0000AA"><i>//---------------------------------------------------------------------------</i></font>

<b>__fastcall</b> TTextDropTarget::TTextDropTarget(TComponent* Owner)

  : TGenericVCLDropTarget(Owner)

{

}

<font color="#0000AA"><i>//---------------------------------------------------------------------------</i></font>

HRESULT <b>__stdcall</b> TTextDropTarget::DragEnter(IDataObject *pDataObject,

                      DWORD grfKeyState, _POINTL pt, DWORD *pdwEffect)

{

  FORMATETC fe;

  setFE(fe,CF_TEXT,TYMED_HGLOBAL); <font color="#0000AA"><i>// fill in structure for text</i></font>

  HRESULT hres = pDataObject-&gt;QueryGetData(&amp;fe); <font color="#0000AA"><i>//do we like what this dataobject has?</i></font>

  <b>if</b> (SUCCEEDED(hres) &amp;&amp; FOnDragEnter)

  {

    <font color="#0000AA"><i>/*the QueryGetData method returns an HRESULT

    depending on whether or not we could

    actually get the data if we tried. If we

    return a failing HRESULT here, the droptarget

    will not allow the drop*/</i></font>

    <font color="#0000AA"><i>//here's where we determine the keystates, etc. for the event</i></font>



    TShiftState ss;

    ss.Clear();

    <b>if</b> (grfKeyState &amp; MK_CONTROL)

      ss = ss &lt;&lt; ssCtrl;

    <b>if</b> (grfKeyState &amp; MK_ALT)

      ss = ss &lt;&lt; ssAlt;

    <b>if</b> (grfKeyState &amp; MK_SHIFT)

      ss = ss &lt;&lt; ssShift;

    <b>if</b> (grfKeyState &amp; MK_LBUTTON)

      ss = ss &lt;&lt; ssLeft;

    <b>if</b> (grfKeyState &amp; MK_MBUTTON)

      ss = ss &lt;&lt; ssMiddle;

    <b>if</b> (grfKeyState &amp; MK_RBUTTON)

      ss = ss &lt;&lt; ssRight;

    FOnDragEnter(TargetControl,pt.x,pt.y,ss);

  }

  <b>return</b> hres;

}

<font color="#0000AA"><i>//---------------------------------------------------------------------------</i></font>

HRESULT <b>__stdcall</b> TTextDropTarget::DragOver(DWORD grfKeyState, _POINTL pt,

                    DWORD *pdwEffect)

{

  <b>if</b> (FOnDragOver)

  {

    TShiftState ss;

    ss.Clear();

    <b>if</b> (grfKeyState &amp; MK_CONTROL)

      ss = ss &lt;&lt; ssCtrl;

    <b>if</b> (grfKeyState &amp; MK_ALT)

      ss = ss &lt;&lt; ssAlt;

    <b>if</b> (grfKeyState &amp; MK_SHIFT)

      ss = ss &lt;&lt; ssShift;

    <b>if</b> (grfKeyState &amp; MK_LBUTTON)

      ss = ss &lt;&lt; ssLeft;

    <b>if</b> (grfKeyState &amp; MK_MBUTTON)

      ss = ss &lt;&lt; ssMiddle;

    <b>if</b> (grfKeyState &amp; MK_RBUTTON)

      ss = ss &lt;&lt; ssRight;

    FOnDragOver(TargetControl,pt.x,pt.y,ss);

  }

  <b>return</b> S_OK; <font color="#0000AA"><i>///we don't really do anything special;</i></font>

}

<font color="#0000AA"><i>//---------------------------------------------------------------------------</i></font>

HRESULT <b>__stdcall</b> TTextDropTarget:: DragLeave()

{

  <b>if</b> (FOnDragLeave)

    FOnDragLeave(TargetControl);

  <b>return</b> S_OK;

}

<font color="#0000AA"><i>//---------------------------------------------------------------------------</i></font>

HRESULT <b>__stdcall</b> TTextDropTarget::Drop(IDataObject *pDataObject, DWORD grfKeyState,

                    _POINTL pt, DWORD *pdwEffect)

{

  <font color="#0000AA"><i>//here's where we do all the stuff that's important.</i></font>

  <b>if</b> (FOnDrop)

  {

    FORMATETC fe;

    STGMEDIUM stg;

    HRESULT hres;

    String dropstr;

    setFE(fe,CF_TEXT,TYMED_HGLOBAL);

    hres = pDataObject-&gt;GetData(&amp;fe,&amp;stg);

    <font color="#0000AA"><i>//GetData returns us data in a storage medium structure.</i></font>

    <b>if</b> (SUCCEEDED(hres))

    {

      dropstr = String((<b>char</b> *)GlobalLock(stg.hGlobal),GlobalSize(stg.hGlobal));

      GlobalUnlock(stg.hGlobal);

      ReleaseStgMedium(&amp;stg);

      TShiftState ss;

      ss.Clear();

      <b>if</b> (grfKeyState &amp; MK_CONTROL)

        ss = ss &lt;&lt; ssCtrl;

      <b>if</b> (grfKeyState &amp; MK_ALT)

        ss = ss &lt;&lt; ssAlt;

      <b>if</b> (grfKeyState &amp; MK_SHIFT)

        ss = ss &lt;&lt; ssShift;

      <b>if</b> (grfKeyState &amp; MK_LBUTTON)

        ss = ss &lt;&lt; ssLeft;

      <b>if</b> (grfKeyState &amp; MK_MBUTTON)

        ss = ss &lt;&lt; ssMiddle;

      <b>if</b> (grfKeyState &amp; MK_RBUTTON)

        ss = ss &lt;&lt; ssRight;

      FOnDrop(TargetControl,pt.x,pt.y,ss,dropstr);

    }

    <b>return</b> hres;

  }

  <b>else</b> <b>return</b> S_OK;

}

<font color="#0000AA"><i>//---------------------------------------------------------------------------</i></font>

<b>namespace</b> Textdroptarget

{

  <b>void</b> <b>__fastcall</b> PACKAGE <b>Register</b>()

  {

     TComponentClass classes[1] = {<b>__classid</b>(TTextDropTarget)};

     RegisterComponents(<font color="#0000FF">&quot;Drop Targets&quot;</font>, classes, 0);

  }

}

<font color="#0000AA"><i>//---------------------------------------------------------------------------</i></font>



</code></pre> 

</td
上一页 12
⌨️ 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 + -