如何在 VB 中使用自定义绘制（回调）

如何在 VB 中使用自定义绘制（回调）

TBarCode V6

'callback function
Public Function MyDrawRow ( ByRef pMyData As Long,
          ByVal pBarCode As UIntPtr, ByVal hDC As IntPtr,
          ByVal hTargetDC As IntPtr,
          ByRef pRect As Rectangle) As UInt32
   Dim strTempo As String
   strTempo = TBC6.BCGetMetaData(pBarCode)
   Return Convert.ToUInt32(0)
End Function

'setting the address of the callback function
Public cb As TBC6.Callback
   cb = AddressOf MyDrawRow
   eCode = TBC6.BCSetFuncDrawRow(hBarcode, cb, pData)

'required declarations
Declare Ansi Function BCDrawCB Lib "TBarCode6.ocx" ( _
          ByRef hBarcode As UIntPtr, _
          ByVal hDC As IntPtr, _
          ByRef pRect As Rectangle, _
          ByVal func As Callback, _
          ByVal func As Callback, _
          ByVal pData As IntPtr ) As Int32

Declare Ansi Function BCGetMetaData Lib "TBarCode6.ocx" ( _
           ByVal hBarcode As UIntPtr ) As String