Internet Explorer 编程简述（十一）完美的Inplace Drag & Drop——“超级拖放”

*pdwEffect = dwTempEffect;

}

return S_OK;

}

 

//根据调用缺省行为前后的Effect值判断是否是往输入框拖拽文字

BOOL CBrowserDropTarget::IsDragTextToInputBox(DWORD dwOldEffect, DWORD dwNewEffect)

{

//如果是把非输入框中文字往输入框拖动，则dwOldEffect与dwNewEffect相等，都是DROPEFFECT_COPY

BOOL bTextSelectionToInputBox = ( dwOldEffect == DROPEFFECT_COPY )

&& ( dwOldEffect == dwNewEffect );

 

//如果是把文字从一个输入框拖到另一个输入框，则dwOldEffect为DROPEFFECT_COPY DROPEFFECT_MOVE，

//而dwNewEffect的值可能为DROPEFFECT_MOVE（默认情况），也可能为DROPEFFECT_COPY（按下Ctrl键时）

BOOL bInputBoxToInputBox = ( dwOldEffect == (DROPEFFECT_COPY DROPEFFECT_MOVE) )

&& ( dwNewEffect == DROPEFFECT_MOVE dwNewEffect == DROPEFFECT_COPY );

 

//来自Microsoft Word的拖拽特殊一些，dwOldEffect是所有效果的组合值

BOOL bMSWordToInputBox =

( dwOldEffect == (DROPEFFECT_COPY DROPEFFECT_MOVE DROPEFFECT_LINK) )

&& ( dwNewEffect == DROPEFFECT_MOVE dwNewEffect == DROPEFFECT_COPY );

 

//来自Edit Plus的拖拽过也特殊一些，dwOldEffect是个负数（怀疑是Edit Plus的拖拽实现有问题）

BOOL bEditPlusToInputBox = ( dwOldEffect < 0 )

&& ( dwNewEffect == DROPEFFECT_MOVE dwNewEffect == DROPEFFECT_COPY );