MDI窗体背景更换图片 ...................\clsMDIBackBMP.cls ...................\Form1.frm ...................\MDIBackBMP.vbw ...................\MDIBackground.RES ...................\MDIForm1.frm ...................\MDIForm1.frx ...................\MDIFrm1.exe ...................\modAPI.bas ...................\PMDIBack.exe ...................\PMDIBack.vbp ...................\PMDIBack.vbw ...................\工程1.vbw