== or String.Equals() - C# Discussion Boards

Hi Prakash,

Create a binary reader by passing any stream that is created on the file. (Which you recieved through command line parameter). Use the binary readers read method to read the content into a byte array. You can use the Byte array's ToString method to convert the content to the necessary format.

fs = File.OpenRead(@"your file name");
BinaryReader br = new BinaryReader(fs);
byte[] buffer = new byte[32768];
int read= br.Read(buffer,0,buffer.Length);
mybytearry[0].ToString("X")---hexa decimal

Guess this will help you.

Thanks and Regards
SGS

Some please send me a code to read a binary file. The code should then change the first 2 bytes to hexadecimal codes..... the next 4 bytes to decimal.... the rest of the file can be in any format......

Hmm.. sounds like a homework project to me.

Regards,
Polis

Can you practice what you teach?

In the tree of the WindowsExplorer, when we click on a node and choose 'rename', the text of that node, maybe, appear in a textbox and we can change that text.

Can u show me how to do that in C#?

Please help me!
Thank you in-advanced!

gyokusei wrote:
Can u show me how to do that in C#?

So, what you are saying here is that you want to simulate this effect on a listview control (or similar controls) into your application (WinForms I suppose)? Or you want access the shell?

Regards,
Polis

Can you practice what you teach?

Just set the LabelEdit property of your TreeView to true and you'll be able to edit it by clicking on it. If you want to trigger an Edit manually use TreeView.BeginLabelEdit().

this.treeTemplates.SelectedNode.BeginEdit();

GanDad

Hi!

I'm currently trying to improve the speed of my xml library TXML, which does not rely on any XML base classes and thus parses the XML string itself to find a certain node.
Because of this I'm interested in finding the fastest way of checking the equality of two strings. On various sites I've read that String.Equals() is supposed to be faster than the == operator, which uses String.op_Equality() under the hood. So I replaced all == comparisons in a certain method with String.Equals() comparisons. The weird thing is that the new code with String.Equals() appears to run 100 ms on average slower than the old code with ==. Can anyone explain me why?

Here's the code of the above mentioned method:

private ReaderReturnValue GetNodeContent(string masterNode, int mnIndex, string subNode, int snIndex)<br />
        {<br />
            int mi = 1;        // masternode iterator<br />
            int si = 1;        // subnode iterator<br />
            int mnLength = masterNode.Length;<br />
            int snLength = subNode.Length;<br />
            int textLength = 0;    // the length of the text that is to be returned<br />
            int i = 0;            // the for iterator<br />
            int snBegin = 0;            // the beginning pos of the subnode<br />
            bool foundMn = false;<br />
            bool foundSn = false;<br />
            bool done = false;    // indicates if we have found the nodes and the text length<br />
<br />
            if(masterNode == "")        // if there is no masterNode specified set foundMn to true<br />
                foundMn = true;<br />
<br />
            for(i = 0; i < XmlText.Length; i++)<br />
            {<br />
                if(XmlText[i] == '<')            // are we currently inside a node?<br />
                {   <br />
<br />
                    if(foundMn == false)    // do we have to search for our masternode?<br />
                    {<br />
                        if(mnLength + 1 <= XmlText.Length - i - 1)            // only continue if we haven't reached the end yet - aka if there are enough chars left to read<br />
                        {<br />
                            if(XmlText.Substring(i + 1, mnLength + 1).Equals(masterNode + '>'))    // have we found our masternode?<br />
                            {<br />
                                if(mi == mnIndex)<br />
                                    foundMn = true;<br />
                                else<br />
                                    mi++;<br />
                            }<br />
                        }<br />
                    }<br />
<br />
                    if(foundMn == true && foundSn == false)    // do we have to search for our subnode?<br />
                    {<br />
                        if(snLength + 1 <= XmlText.Length - i - 1)        // only continue if we haven't reached the end yet - aka if there are enough chars left to read<br />
                        {<br />
                            if(XmlText.Substring(i + 1, snLength + 1).Equals(subNode + '>'))            // have we found our subnode?<br />
                            {<br />
                                if(si == snIndex)<br />
                                {<br />
                                    foundSn = true;<br />
                                    snBegin = i + snLength + 2;            // set the beginning of the subnode<br />
                                }<br />
                                else<br />
                                    si++;<br />
                            }<br />
                        }<br />
                    }<br />
<br />
                    if(mnLength + 1 <= XmlText.Length - i - 1)            // only continue if we haven't reached the end yet - aka if there are enough chars left to read<br />
                    {<br />
                        if(foundMn == true)                    // have we already found our masternode?<br />
                        {<br />
                            if(XmlText.Substring(i + 1, mnLength + 2).Equals('/' + masterNode + '>'))    // have we reached the end of the masternode?<br />
                                break;                            // then we'll end this loop<br />
                        }<br />
                    }<br />
<br />
                    if(foundSn == true)                    // have we already found our subnode?<br />
                    {<br />
                        if(mnLength + 1 <= XmlText.Length - i - 1)            // only continue if we haven't reached the end yet - aka if there are enough chars left to read<br />
                        {<br />
                            if(XmlText.Substring(i + 1, snLength + 2).Equals('/' + subNode + '>'))    // have we found the end of our subnode?<br />
                            {<br />
                                done = true;<br />
                                break;<br />
                            }<br />
                            else<br />
                                textLength++;<br />
                        }<br />
                    }<br />
<br />
                }            // if(XmlText[i] == '<')<br />
                else<br />
                {<br />
                    if(foundSn == true)                            // have we found all our nodes?<br />
                        textLength++;<br />
                }<br />
<br />
            }                // for...<br />
<br />
            // create the new ReaderReturnValue<br />
            ReaderReturnValue returnValue = new ReaderReturnValue();<br />
<br />
            if(done == true)                                        // have we found everything we need?<br />
            {<br />
                // fill returnValue with the node content and set foundNode to true<br />
                returnValue.text = XmlText.Substring(snBegin, textLength - snLength - 2);<br />
                returnValue.foundNode = true;<br />
            }   <br />
            else<br />
                returnValue.foundNode = false;<br />
<br />
            // return returnValue<br />
            return returnValue;<br />
        }

I looked at the implementation of op_Equality and Equals. It looks like op_Equality ends up calling Equals in its implementation, after doing some null checking. I don't know why calling op_Equality is faster.

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

Due to some misconfiguration in my Profiler I originally thought op_Equality() to be faster, which in fact isn't the true case. Apparently the null checking that is performed in op_Equality() makes it a little slower than Equals().
Thanks for your help!

i've got two form, when i clicked a button on the first, it opened the second. How could i interact with the first from the second, i mean Could i reference to a windows form from another

Thanks in advance

vuthaianh wrote:
Could i reference to a windows form from another

Ofourse you can. A form is a class like everything else. If you have assigned public variables or methods in the class you want to access then you can access them from any other class in your solution.

E.g. you have 2 classes, Form1 and Form2 and you want to access Form2 from Form1.
(1) First of all you create one instance of each class:

Form1 <code>myFirstForm </code>= new Form1();
Form2 <code>mySecondForm </code>= new Form2();

(2) Assuming that you have publicly available fields or methods in Form2 then you can access them from any class, including Form1. So if you wanted to call a method located inside Form2 from somewhere within Form1 you could say:

int <code>myRate </code>= mySecondForm.CalculateRate();

Hope this helps

Regards,
Polis

Can you practice what you teach?

One thing that Polis didn't mention was the use of events and delegates. You can hook into events that another form (i.e., FormB) exposes to notify your main form (i.e., FormA). This will allow you to maintain private methods across both forms and still transfer data.

- Nick Parker
Microsoft MVP - Visual C#
My Blog | My Articles

Yes, Nick makes a good point there with events and delegates. I guess the rest is up to you

Regards,
Polis

Can you practice what you teach?

How do I execute a stored procedure in the Page_Load function of C#?

Thanks!

Illegal Operation

WannaBe and GonnaBe Systems Developer

The same way you would execute a stored procedure anywhere else.

I'll assume you are using SQL Server 2000

SqlConnection conn = new SqlConnection(myConnectionString);
SqlCommand cmd = new SqlCommand(storedProcName, conn);
// Add any parameters to the command here
conn.Open();
// Run only one of the following lines depending on what you are expecting.
cmd.ExecuteNonQuery(); // Sproc returns no data 
myValue = cmd.ExecuteScalar(); // Sproc returns a single value 1st col 1st row
myReader = cmd.ExecuteReader(); // Sproc returns many rows

// Everything done. close the connection.
conn.Close();

My: Blog | Photos | Next SQL Presentation
WDevs.com - Open Source Code Hosting, Blogs, FTP, Mail and More

thanks for the help.

Just one more question?

Where does the "myReader" fit into the picture? I have inserted the line:

myReader = MyProc.executeReader();

Thanks!

Illegal Operation

WannaBe and GonnaBe Systems Developer

Illegal Operation wrote:
Where does the "myReader" fit into the picture?

It is a SqlDataReader. e.g.

SqlDataReader myReader = myProc.ExecuteReader();

You will then need to set up a loop to iterate through all the rows. e.g.

while(myReader.Read())
{
    // use the SqlDataReader's Get... methods to extract the data.
}

You can find out more about Execute reader from the MSDN Documentation[^]

My: Blog | Photos | Next SQL Presentation
WDevs.com - Open Source Code Hosting, Blogs, FTP, Mail and More

I have an item that is a tag value to a list view, and the list view item is also contained in the object. The relationship is two way.

My question is, if i remove these objects, will it persist in memory due to the fact that they refference each other?

From what i've read of the Garbage collector, it will perform a graph search for all objects reachable from root objects. So even if my two objects DO refference each other, they will be removed if they are unreachable from the root objects.

Is this right?

Cheers

Cata

That's right. It will remove them.

WM.

What about weapons of mass-construction?

Hi, is it possible to include the myApp.exe.manifest file in the exe file so that I don't have to have two separate files, one exe and one manifest? If so, how should I do this? (Visual Studio .NET 2003, C#)

http://www.codeproject.com/csharp/dotnetvisualstyles.asp[^]

Never forget: "Stay kul and happy" (I.A.)

David's thoughts / dnhsoftware.org / MyHTMLTidy

hi,
i have made a service wich loads a another program ,my codes are correct but when i use these codes in my service,they dont work.
here is my codes:

<br />
System.IO.Directory.SetCurrentDirectory(myappPath);<br />
Process.Start("MyApplication" );<br />

i want to know why it happens?

What does not work?

Does the application not start? Have you checked with the TaskManager if it really does not start or is it started and you can't just see it?

Normally, a service application cannot interact with the desktop. Because of that, if you start an application from a service, the application will not be visible to the user.

To allow a service to interact with the desktop open the Service Control Manager. Select your service and open the properties.
- Select the "Log On" tab
- Select "Log on as: Local System account" and enter a valid account and password
- Check "Allow service to interact with desktop.

hth

Claudio
Claudio's Website
Hommingberger Gepardenforelle

Hi folks,

I need to write a piece of code that will list all the files in a folder in another machine.
Could you guys give me a hint?

Thanks.