主题：[求助]请问如何获取网页上图片的文件大小？

参考9楼的方式

9楼的代码耗时比较多，效率低，如果用下面的代码 该如何捕获呢？

 

 

Dim hc As New HttpClient("http://www.foxtable.com/lib/images/bottomlogo1.gif")
try
    If hc.GetFile("d:\123.jpg") Then
        MessageBox.show("文件下载成功","提示")
    Else
        MessageBox.show("文件下载失败","提示")
    End If
catch ex As exception
    MessageBox.show("文件下载失败2","提示")
End try

这种捕捉比较麻烦，要写事件代码

 

http://www.foxtable.com/webhelp/scr/2655.htm

 

试过，但这种的话，我在BeforeShowErrorMessage事件里加上  e.Cancel = true   程序就直接给闪退了

效率问题，那就改成这样

 

Dim image_address As String = "http://www.foxtable.com/lib/images/bottomlogo.gif"
try
    Dim wr As system.net.WebRequest = system.net.WebRequest.Create(image_address)
    Dim res As system.net.WebResponse= wr.GetResponse
    Dim stm As System.IO.Stream = res.GetResponseStream
    Dim ms As New IO.FileStream("d:\000.jpg", IO.FileMode.Create)
    Dim buffer(1024) As Byte
    Dim count = stm.read(buffer, 0, buffer.length)   
    Do While (count > 0)
        ms.Write(buffer, 0, count)
        count = stm.Read(buffer, 0, buffer.Length)
    Loop
    stm.Close()
    ms.Dispose()
    msgbox("ok")
catch ex As exception
    msgbox(ex.message)
    msgbox("abc")
End try

厉害 ！！！

 

再请教  ：

 

try
    Dim pbx As WinForm.PictureBox = e.Form.Controls("PictureBox1")
    pbx.ImageFile = "http://www.foxtable.com/lib/images/bottomlogo1.gif"
catch  ex As exception
    msgbox(ex.message)
End try

 

这个又如何捕获错误呢？

Dim image_address As String = "http://www.foxtable.com/lib/images/bottomlogo1.gif"
try
    Dim wr As system.net.WebRequest = system.net.WebRequest.Create(image_address)
    Dim res As system.net.WebResponse= wr.GetResponse
    Dim bmp As New Bitmap(res.GetResponseStream)
   
    Dim pbx As WinForm.PictureBox = e.Form.Controls("PictureBox1")
    pbx.Image = bmp
catch  ex As exception
    msgbox(ex.message)
End try