在vb.net中如何实现单击按钮弹出文件选择框，效果如下这个页面中的“upload multiple files nows”按钮，

Question

http://ajaxuploader.com/Demo/multiple-files-upload.aspx

Answer 1

有个c#的例子，你参考一下把
Below is now the code for the main page used to upload multiple images.
Default.aspx
This is the code inside the form tag
<div>
<asp:Label ID="Label1" runat="server" Text="Locate File:" />
<asp:FileUpload ID="fileUp" runat="server" />
<br />
<asp:Label ID="Description" runat="server" Text="Description:"></asp:Label>
<asp:TextBox ID="txtDesc" runat="server" Width="349px"></asp:TextBox>
<asp:Button ID="btnAddFile" runat="server" Text="Add File To Upload List"
onclick="btnAddFile_Click" />
</div>

<div>
<asp:Label ID="lblCurrentFileCount" runat="server"></asp:Label>
<br />
<asp:DataList ID="dlPhotoFiles" runat="server" RepeatColumns="10" RepeatDirection="Horizontal">
<ItemTemplate>
<asp:Image ID="Image1" runat="server" ImageUrl='<%# string.Format("~/getImage.aspx?id={0}", Eval("id")) %>'
Width="50" AlternateText='<%# Eval("fileDesc") %>' />
<br />
<asp:LinkButton ID="lnkBtnRemovePhoto" runat="server"
CommandArgument='<%# Eval("id") %>' OnCommand="lnkBtnRemovePhoto_Command">Remove</asp:LinkButton>
</ItemTemplate>
</asp:DataList>
<br />
</div>
<br />
<div>
<asp:Button ID="btnUploadFiles" runat="server" Text="Upload File(s)"
onclick="btnUploadFiles_Click" />
</div>

Default.aspx.cs
This is all of the code behind:
DataSet dsPhotosFiles = new DataSet();
protected void Page_Init(object sender, EventArgs e)
{
if (Session["dsPhotoFiles"] == null)
{
this.initPhotoDS();
Session.Add("dsPhotoFiles", dsPhotosFiles);
}
else
{
dsPhotosFiles = (DataSet)Session["dsPhotoFiles"];
}
}
protected void btnAddFile_Click(object sender, EventArgs e)
{
if (fileUp.PostedFile.ContentLength > 0)
{
//TODO: logic for file extension check
DataRow dr = dsPhotosFiles.Tables[0].NewRow();
string fileExt = System.IO.Path.GetExtension(fileUp.PostedFile.FileName);
byte[] imageBytes = new byte[fileUp.PostedFile.InputStream.Length];
fileUp.PostedFile.InputStream.Read(imageBytes, 0, imageBytes.Length);
dr["fileBytes"] = imageBytes;
dr["filePath"] = fileUp.PostedFile.FileName;
dr["fileDesc"] = txtDesc.Text;
dr["id"] = System.Guid.NewGuid().ToString();
dsPhotosFiles.Tables[0].Rows.Add(dr);
}
this.bindDataList();
txtDesc.Text = "";
lblCurrentFileCount.Text = "Current Files To Upload: " + dsPhotosFiles.Tables[0].Rows.Count;
}
protected void btnUploadFiles_Click(object sender, EventArgs e)
{
try
{
for (int i = 0; i < dsPhotosFiles.Tables[0].Rows.Count; i++)
{
//TODO:logic to save image path and description to database

string fileName = System.IO.Path.GetFileName(dsPhotosFiles.Tables[0].Rows[i]["filePath"].ToString());
byte[] imageBytes;
imageBytes = (byte[])dsPhotosFiles.Tables[0].Rows[i]["fileBytes"];
//their is no uploading..just writing out the bytes to the directory on the web server.
System.IO.File.WriteAllBytes(Server.MapPath(string.Format("~/documents/{0}", fileName)), imageBytes);
}
//TODO: show success message logic
//clear out rows of dataset not the whole dataset
dsPhotosFiles.Tables[0].Rows.Clear();
this.bindDataList();
lblCurrentFileCount.Text = "Current Files To Upload: " + "0";

}
catch (Exception ex)
{
//TODO: show error message of which file did not get uploaded
throw new Exception(ex.Message);
}

}
private void initPhotoDS()
{
dsPhotosFiles.Tables.Add("Photos");
dsPhotosFiles.Tables[0].Columns.Add("fileBytes", Type.GetType("System.Byte[]"));
dsPhotosFiles.Tables[0].Columns.Add("filePath");
dsPhotosFiles.Tables[0].Columns.Add("fileDesc");
dsPhotosFiles.Tables[0].Columns.Add("id");
}
private void bindDataList()
{
dlPhotoFiles.DataSource = dsPhotosFiles;
dlPhotoFiles.DataKeyField = "id";
dlPhotoFiles.DataBind();
}
protected void lnkBtnRemovePhoto_Command(object sender, CommandEventArgs e)
{
foreach(DataRow dr in dsPhotosFiles.Tables[0].Rows)
{
if (dr["id"].ToString() == e.CommandArgument.ToString())
{
dsPhotosFiles.Tables[0].Rows.Remove(dr);
break;
}
}
this.bindDataList();
lblCurrentFileCount.Text = "Current Files To Upload: " + dsPhotosFiles.Tables[0].Rows.Count;
}

Answer 2

在VB中可以用通用对话框CommonDialog

工程——部件——如图

详细用法请百度

有问题请追问，满意请采纳！