替换pic控件中的图片

integer li_FileNum,ret,loops,i
long filelen
blob pic,b
string txtname,named
string defext = 'BMP'
string filter = 'bitmap files(*.bmp),*.bmp,jpg files(*.jpg),*.jpg'
//打开选择文件对话框
ret = GetFileOpenName('Open Picture Dialog',txtname,named,defext,filter)
if ret = 1 then  //执行成功
 filelen = FileLength(txtname)  //得到文件长度
 li_FileNum = FileOpen(txtname,StreamMode!)  //流模式打开文件，并返回打开文件的句柄
 if li_FileNum <> -1 then  //执行成功
  // Determine how many times to call FileRead
        IF filelen > 32765 THEN
   IF Mod(filelen, 32765) = 0 THEN
    loops = filelen/32765
   ELSE
    loops = (filelen/32765) + 1
   END IF
  ELSE
   loops = 1
  END IF
  // Read the file into b
  FOR i = 1 to loops
   FileRead(li_FileNum, b)  //li_FileNum为文件句柄，由FileOpen()函数得到
   pic += b
  NEXT
  // Closes the file opened by FileOpen()
  FileClose(li_FileNum)
  // 设置新图片
  p_1.setpicture(pic)
 end if
end if