主题：怎么打开文件，不显示，页面是空的，怎么回事，请指教

修改红色代码

Dim fl As String = "d:\web\" & e.path
If filesys.FileExists(fl)
    Dim idx As Integer = fl.LastIndexOf(".")
    Dim ext As String  = fl.SubString(idx)
    Select Case ext
        Case ".jpg",".gif",".png",".bmp",".wmf",".js",".css" ,".html",".htm",".zip",".rar",".chm"
            e.WriteFile(fl)
            Return '这里必须返回
    End Select
End If

chm文件，是无法直接在线预览的。必须下载后打开。

如果要在线预览chm，必须转换成htm才行 https://www.baidu.com/baidu?wd=chm%E8%BD%AChtml