Placing cursor at the end of the text in a textbox

function SetCursorToTextEnd(textControlID)
{
var text = document.getElementById(textControlID);
if (text != null && text.value.length > 0)
{
if (text.createTextRange)
{
var FieldRange = text.createTextRange();
FieldRange.moveStart('character', text.value.length);
FieldRange.collapse();
FieldRange.select();
}
}
}

Scrolling Div to bottom

//div1 is the id of the div tag to be scrolled
private void ScrollToBottom()
{
string jscript =
"objDiv = document.getElementById('div1');
objDiv.scrollTop=objDiv.scrollHeight;";

ScriptManager.RegisterClientScriptBlock(this.Page, typeof(Page), "scrollscript", jscript, true);
}

Uploading and Downloading file using HttpWebRequest

Hi peoples,

Today am going to write two functions that will help to Upload & Download
files to and from another website.


public bool UploadFileEx(string fileName, string token, string url, string fileFormName, string contenttype, NameValueCollection querystring, CookieContainer cookies, byte[] fileBytes)
{
try
{
if ((fileFormName == null) ||(fileFormName.Length == 0))
{
fileFormName = "file";
}

if ((contenttype == null) ||(contenttype.Length == 0))
{
contenttype = "application/octet-stream";
}


string postdata = "";
if (querystring != null)
{
foreach (string key in querystring.Keys)
{
postdata += key + "=" + querystring.Get(key) + "&";
}
}
Uri uri = new Uri(url + postdata);
string boundary = "----------" + DateTime.Now.Ticks.ToString("x");
HttpWebRequest webrequest = (HttpWebRequest)WebRequest.Create(uri);
webrequest.ContentType = "multipart/form-data; boundary=" + boundary;
webrequest.Method = "POST";
// Build up the post message header
StringBuilder sb = new StringBuilder();
sb.Append("--");
sb.Append(boundary);
sb.Append("\r\n");
sb.Append("Content-Disposition: form-data; name=\"");
sb.Append(fileFormName);
sb.Append("\"; filename=\"");
sb.Append(fileName);
sb.Append("\"");
sb.Append("\r\n");
sb.Append("Content-Type: ");
sb.Append(contenttype);
sb.Append("\r\n");
sb.Append("\r\n");
string postHeader = sb.ToString();
byte[] postHeaderBytes = Encoding.UTF8.GetBytes(postHeader);
byte[] boundaryBytes = Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n");
long length = postHeaderBytes.Length + fileBytes.Length + boundaryBytes.Length + 2;
webrequest.ContentLength = length;
Stream requestStream = webrequest.GetRequestStream();
requestStream.Write(postHeaderBytes, 0, postHeaderBytes.Length);
requestStream.Write(fileBytes, 0, fileBytes.Length);
boundaryBytes = Encoding.ASCII.GetBytes("\r\n--" + boundary + "--\r\n");
requestStream.Write(boundaryBytes, 0, boundaryBytes.Length);
WebResponse responce = webrequest.GetResponse();
Stream s = responce.GetResponseStream();
StreamReader sr = new StreamReader(s);
string r = sr.ReadToEnd();
responce.Close();
return true;
}
catch(Exception ex)
{
return false;
}
}

Now Downloading

private bool DownloadFile(string arg)
{
try
{
string url = arg;
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
int bufferSize = 1
//Initialize the output stream
Response.Clear();
Response.AppendHeader("Content-Disposition:", "attachment; filename=" + args);
Response.AppendHeader("Content-Length", resp.ContentLength.ToString());
Response.ContentType = "application/download";
//Populate the output stream
byte[] ByteBuffer = new byte[bufferSize + 1];
MemoryStream ms = new MemoryStream(ByteBuffer, true);
Stream rs = req.GetResponse().GetResponseStream();
byte[] bytes = new byte[bufferSize + 1];
while (rs.Read(ByteBuffer, 0, ByteBuffer.Length) > 0)
{
Response.BinaryWrite(ms.ToArray());
Response.Flush();
}

//Cleanup
Response.End();
ms.Close();
ms.Dispose();
rs.Dispose();
ByteBuffer = null;
return true;
}
catch (Exception ex)
{
//File download failed;
return false;
}
}


Hope this will help you.


Asp.Net Multiline TextBox + Default Button

Hi guys,

I got into this interesting problem while developing a chat web client.
Basically i was trying to do some POC. Since i haven't had enough
time with me, i used a multiline textbox as the chat input element.

And the send button is set as the default button.
Since the textbox is multiline, if we press enter key,
as its behavior it will produce a newline inside the textbox.

What i want is to fire the send button event.

For that i wrote the following JavaScript.

sendText.Attributes.Add("onkeydown", "javascript: return keydownHandler('"+ sendBtn.ClientId + "')");

function keydownHandler(sendBtnId)
{
if(event.which || event.keyCode)
{
if ((event.which == 13) || (event.keyCode == 13))
{
document.getElementById(sendBtnId).click();
return false;
}
}
else
{
return true
}
}

ASP.Net Caching

We can easily cache data in asp.net using the Caching class provided by asp.net

Here is an example of how to cache data.

if(Cache["data"]==null)
{
Cache.Insert("data", data, null, System.Web.Caching.Cache.NoAbsoluteExpiration, System.Web.Caching.Cache.NoSlidingExpiration);
}

This will cache the "data" until it is removed from the memory.

So how can we know when the cached data is being removed from the memory?

ASP.Net provides a cool feature, that enables us to do it.

There is a delegate to achieve this
System.Web.Caching.CacheItemRemovedCallback
which has the following signature

void RemoveCacheItemHandler(string key, Object value, CacheItemRemovedReason reason);

This delegate can be used to get notification once a particular cached item being removed.

Example of how we can use the delegate:

if(Cache["data"]==null)
{
Cache.Insert("data", data, null, System.Web.Caching.Cache.NoAbsoluteExpiration, System.Web.Caching.Cache.NoSlidingExpiration, RemoveCacheItemHandler);
}

public void RemovedCacheItemHandler(string key, Object value, CacheItemRemovedReason reason)
{
switch (key)
{
case "data":
// cache has been removed; do the process
break;
}
}

Tracking changes in Microsoft Word Document

In tools select Track Changes.


You can make sure the word is tracking changes by looking for "TRK" in status bar.

Query String + Special Characters

For sending special characters as Querystring

In javascript we can use the function escape to encode
In .Net we can user Server.URLEncode

To decode the string we can use unescape in javascript
and Server.URLDecode in .Net


Thats all ;p