With the use of following code you can convert all uploaded images to thumbnail
images.
To convert uploaded image to thumbnail this article provides a few steps which
will be easy to follow.
Step 1:
Design a Form drag FileUpload Control from toolbox .I have Taken 10 FileUpload
Control.
<table
class="style3">
<tr>
<td>
</td>
<td>
</td>
<td
colspan="3">
<fieldset>
<legend>Upload
Multiple Photos</legend>
<div
id="div1"
runat="server">
<input
type="file"
size="65"
runat="server"
id="FileUpload1">
<input
type="file"
size="65"
runat="server"
id="FileUpload2">
<input
type="file"
size="65"
runat="server"
id="FileUpload3">
<input
type="file"
size="65"
runat="server"
id="FileUpload4">
<input
type="file"
size="65"
runat="server"
id="FileUpload5">
</div>
<br
/>
<div
id="div2"
runat="server"
visible="false">
<input
type="file"
size="65"
runat="server"
id="FileUpload6">
<input
type="file"
size="65"
runat="server"
id="FileUpload7">
<input
type="file"
size="65"
runat="server"
id="FileUpload8">
<input
type="file"
size="65"
runat="server"
id="FileUpload9">
<input
type="file"
size="65"
runat="server"
id="FileUpload10">
</div>
<asp:Label
ID="lblError1"
runat="server"
Text="Label"></asp:Label>
<asp:Label
ID="MessageLabel"
runat="server"
ForeColor="Red"></asp:Label>
<br
/>
<asp:Button
ID="btnUpload"
runat="server"
Text="Upload"
OnClick="btnUpload_Click"
style="height:
26px" />
<asp:Button
ID="ButtonMore"
runat="server"
Text="Add 10 Photos"
OnClick="ButtonMore_Click"
/>
</fieldset>
<br
/>
<div
id="div5"
runat="server"
visible="false">
</div>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
</table>
Step 2:
On Upload button's Click event write following code…..
Directory.CreateDirectory(Server.MapPath("RealImage\\"));
div5.Visible =
true;
HttpFileCollection uploadFilCol =
Request.Files;
Control[] f = new
Control[10]{FileUpload1,
FileUpload2,
FileUpload3,
FileUpload4,
FileUpload5,
FileUpload6,
FileUpload7,
FileUpload8,
FileUpload9,
FileUpload10 };
for (int i = 0;
i < uploadFilCol.Count; i++)
{
HttpPostedFile file = uploadFilCol[i];
string fileExt = Path.GetExtension(file.FileName).ToLower();
string fileName =
Path.GetFileName(file.FileName);
HtmlInputFile htmlFile = (HtmlInputFile)f[i];
if (htmlFile.PostedFile.ContentLength
> 0)
{
string sFormat = String.Format("{0:#.##}", (float)htmlFile.PostedFile.ContentLength
/ 2048);
if (float.Parse(sFormat)
< float.Parse("2048"))
{
if (htmlFile.PostedFile !=
null)
{
ViewState["ImageName"]
=
htmlFile.PostedFile.FileName.Substring(htmlFile.PostedFile.FileName.LastIndexOf("\\")
+ 1);//browseImagePath[0];
}
else
{
ViewState["ImageName"]
= "";
}
else
{
lblError1.Visible = true;
lblError1.Text = "Image Size is
Large, please resize it !!";
}
}
else
{
ViewState["ImageName"] =
"";
if (ViewState["ImageName"].ToString()
== "")
{
lblError1.Visible = true;
lblError1.Text = "Attach an
image to upload";
}
}
MakeThumbnail(htmlFile);
}
Write Thumbnailcallback function which is returning true
public
bool ThumbnailCallback()
{
return true;
}
Step 3:
On More Button's click event write following code,with the use of this code you
can enable 10 file upload control ,means you can upload 10 files at a time.
protected
void ButtonMore_Click(object
sender, EventArgs e)
{
if (ButtonMore.Text ==
"Only five")
{
div2.Visible = false;
ButtonMore.Text = "Add 10 Photos";
}
else if
(ButtonMore.Text == "Add 10 Photos")
{
div2.Visible = true;
ButtonMore.Text = "Only five";
}
}
}
Step 4:
Write Following Function which is use to convert high resolution image to
thumbnail.
private
void MakeThumbnail(HtmlInputFile
htmlFile)
{
System.Drawing.Image myThumbnail150;
object obj =
new object();
obj = htmlFile;
System.Drawing.Image.GetThumbnailImageAbort
myCallback = new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback);
HtmlInputFile hFile = (HtmlInputFile)obj;
if (hFile.PostedFile !=
null && hFile.PostedFile.ContentLength > 0)
{
//this code used to remove some symbols
between image name and replace with space
string imgname1 =
hFile.PostedFile.FileName.Replace('%',
' ').Substring(hFile.PostedFile.FileName.LastIndexOf("\\")
+ 1);
string imgname2 = imgname1.Replace('#',
' ').Substring(imgname1.LastIndexOf("\\")
+ 1);
string imgname3 = imgname2.Replace('@',
' ').Substring(imgname1.LastIndexOf("\\")
+ 1);
string imgname4 = imgname3.Replace(',',
' ').Substring(imgname1.LastIndexOf("\\")
+ 1);
string imgname5 = imgname4.Replace('&',
' ').Substring(imgname1.LastIndexOf("\\")
+ 1);
Finalimagename = imgname5.ToString();
string imgname =
hFile.PostedFile.FileName.Substring(hFile.PostedFile.FileName.LastIndexOf("\\")
+ 1);
string sExtension =
imgname.Substring(imgname.LastIndexOf(".") +
1);
//this code is used to check image extension
if (sExtension.ToLower() ==
"jpg" || sExtension.ToLower() ==
"gif" || sExtension.ToLower() ==
"bmp" || sExtension.ToLower() ==
"jpeg" || sExtension.ToLower() ==
"png")
{
if (!File.Exists(MapPath("RealImage\\"
+ Finalimagename)))
{
hFile.PostedFile.SaveAs(ResolveUrl(Server.MapPath("RealImage\\"
+ Finalimagename)));
System.Drawing.Image imagesize =
System.Drawing.Image.FromFile(ResolveUrl(Server.MapPath("RealImage\\"
+ Finalimagename)));
Bitmap bitmapNew =
new Bitmap(imagesize);
if (imagesize.Width <
imagesize.Height)
{
myThumbnail150 = bitmapNew.GetThumbnailImage(150 * imagesize.Width / imagesize.Height, 150, myCallback, IntPtr.Zero);
}
else
{
myThumbnail150 = bitmapNew.GetThumbnailImage(150,
imagesize.Height * 150 / imagesize.Width, myCallback,
IntPtr.Zero);
}
//Create a new directory name
ThumbnailImage
Directory.CreateDirectory(Server.MapPath("ThumbnailImage"));
//Save image in TumbnailImage
folder
myThumbnail150.Save(ResolveUrl(Server.MapPath("ThumbnailImage\\"))
+ Finalimagename, System.Drawing.Imaging.ImageFormat.Jpeg);
MessageLabel.Text =
"Successfully uploaded";
}
}
else
{
lblError1.Visible = true;
lblError1.Text = "Check image
extension";
}
}
}
Step 5:
Run Your Website.
Note: Don't forget to add namespace using System.IO .
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