C# Discussion Boards - CodeProject

smithakk2-Jul-12 20:28

2-Jul-12 20:28

As a part of my project i need c# code for compairing two finger print images. I already had some finger prints. so I need help to check whether the two finger prints matching. No need of fingerprint scanner.
please help me..
Thanks in advance.

Re: Finger print matching

Midnight Ahri2-Jul-12 21:09

Midnight Ahri

2-Jul-12 21:09

i understand what you are asking about, so i think the answer is number 2 from this link.
interesting project, best luck. Smile | :)

Re: Finger print matching

Mycroft Holmes2-Jul-12 21:34

Mycroft Holmes

2-Jul-12 21:34

having followed Midnights link do you have a more detailed question to ask or are you just here to ask for the code.

Never underestimate the power of human stupidity
RAH

Re: Finger print matching

Abhinav S2-Jul-12 22:01

Abhinav S

2-Jul-12 22:01

A Framework in C# for Fingerprint Verification[^] could help you out.

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How to read bytes from Stream into Objects?

Software20072-Jul-12 17:27

Software2007

2-Jul-12 17:27

I am sending data from mobile app to REST in binary format like this:

"firstname=Mike&lastname=Smith&..binary represenation for the image here.."

class Employee{
string firstname;
string lastname;
Stream photo;
}

public string PostMethod(Stream streamObj)
       {
           using (FileStream filetoUpload = new FileStream(filePath + filename, FileMode.Create))
           {
               byte[] byteArray = new byte[10000];
               int bytesRead = 0;

               do
               {
                   bytesRead = streamObj.Read(byteArray, 0, byteArray.Length);
                   if (bytesRead > 0)
                   {
                       filetoUpload.Write(byteArray, 0, bytesRead);
                   }
               }

               while (bytesRead > 0);
           }

           return "Uploaded " + filePath + filename;
       }

I do know how to get the contents of the Stream into a byte array. What do I need to do to be able to read the bytes from the StreamObj into the class? Some pseudo code would be helpful.
employee.firstname = ...
employee.lastname=...
employee.photo=....

modified 3-Jul-12 0:09am.

Re: How to read bytes from Stream into Objects?

Richard MacCutchan2-Jul-12 21:47

Richard MacCutchan

2-Jul-12 21:47

First you need to split your array into sections as delineated by the & character. You can then convert the first two to properly encoded character strings using the System.Text.Encoding.GetChars()[^] method, and then split them based on the = character.

speaking as ...

Re: How to read bytes from Stream into Objects?

OriginalGriff2-Jul-12 23:25

OriginalGriff

2-Jul-12 23:25

Might not work - I think he needs to look a little more closely at his data. The third section is raw binary by my interpretation, so it probably shouldn't be in a string at all or he runs the risk of unicode conversion problems.

Ideological Purity is no substitute for being able to stick your thumb down a pipe to stop the water

Re: How to read bytes from Stream into Objects?

Richard MacCutchan2-Jul-12 23:39

Richard MacCutchan

2-Jul-12 23:39

My suggestions were largely guesswork, but I wasn't proposing to convert section 3 to a string, just the first two.

speaking as ...

Re: How to read bytes from Stream into Objects?

Eddy Vluggen3-Jul-12 1:01

Eddy Vluggen

3-Jul-12 1:01

Software2007 wrote:
I do know how to get the contents of the Stream into a byte array.

Google for Serialize/deserialize - takes only a few lines of code. You'll be wanting the BinaryFormatter.

Bastard Programmer from Hell Suspicious | :suss:

if you can't read my code, try converting it here[^]

Re: How to read bytes from Stream into Objects?

Software20073-Jul-12 6:42

Software2007

3-Jul-12 6:42

OriginalGriff is correct that the image section is raw binary. So, what to do again?

Re: How to read bytes from Stream into Objects?

Eddy Vluggen3-Jul-12 7:00

Eddy Vluggen

3-Jul-12 7:00

Serialize your employee, using the binaryformatter Smile | :)

Serializing means that you'd encode it in a portable format. You can use different formatters, but the Xml-version doesn't sound too appropriate under these circumstances, hence the binaryformatter.

Bastard Programmer from Hell Suspicious | :suss:

if you can't read my code, try converting it here[^]

Re: How to read bytes from Stream into Objects?

Software20073-Jul-12 7:35

Software2007

3-Jul-12 7:35

Can you elaborate a bit. So, I have a stream

"firstname=Mike&lastname=Smith&..binary represenation for the image here.."

in binary format.

[Serializable]
    public class Employee {
Serialize()..
Deserialize()..
}

This sounds like I need a file for the serialization, but I thought this was memory data type of thing.
Anyways, what after this, how do I read it in to the class members what I don't get?
How do I go from Stream type which is sent to me to Employee? Note, stream comes from iphone app.

modified 3-Jul-12 14:09pm.

SpellChecker

Murugavel Sadagopan2-Jul-12 15:43

Murugavel Sadagopan

2-Jul-12 15:43

Hi,

I have created a Texteditor using C#. In this I am using Spellchecker with the help of NHunspell.

When i am entering more than 60000 characters its hanged. Its performance is too slow. But its very fast while the spellchecker is off.

How can i achieve the spellchecker is on for the customer view page only onto the entire.

The following code that i can used for dictionary on/off

if (btnsCheck.BackColor==Color.Green)
{
this.NHunspellTextBoxExtender1.SetSpellCheckEnabled(this.TextEditor, false);
this.NHunspellTextBoxExtender1.SpellAsYouType = false;
btnsCheck.BackColor = Color.Red;
}
else
{
this.NHunspellTextBoxExtender1.SetSpellCheckEnabled(this.TextEditor, true);

string TempSt = this.TextEditor.SelectedText;
this.NHunspellTextBoxExtender1.SpellAsYouType = true;
this.TextEditor.SelectedText = " quot;;
btnsCheck.BackColor = Color.Green;
}
}

Thanks,
Murugavel S

Re: SpellChecker

Abhinav S2-Jul-12 16:27

Abhinav S

2-Jul-12 16:27

Have a look at NHunspellTextBoxExtender - A Spellchecking IExtenderProvider for TextBoxes using Hunspell for .NET[^].

Look at the Optimizations section in the article.
Preventing redrawing and scrolling could improve performance too.

Build your own survey - http://www.factile.net

Re: SpellChecker

Unnikrishnan_S_N3-Jul-12 3:07

Unnikrishnan_S_N

3-Jul-12 3:07

Hi Murugavel,

I think you should be using background thread to do spell checks to overcome UI unresponsiveness.
Execute your spellcheck call this.NHunspellTextBoxExtender1.SetSpellCheckEnabled(this.TextEditor, false); in a different thread.

http://msdn.microsoft.com/en-us/library/cc221403%28v=vs.95%29.aspx[^]

Message Removed

2-Jul-12 8:19

N_tro_P

2-Jul-12 8:19

Message Removed

Re: Modify Top most

Alan N2-Jul-12 9:30

Alan N

2-Jul-12 9:30

This is one of the uses of the Windows SetWindowPos function and is demonstrated with an annoying program that makes all open Notepad windows topmost for 10 seconds. That's just long enough to click on them a few times to confirm the modified behaviour before they revert to normal.

Alan.

using System;
using System.Diagnostics;
using System.Threading;
using System.Runtime.InteropServices;
namespace MakeTopMost {
  internal sealed class App {
    /// <summary>
    /// Flags values for SetWindowPos function
    /// </summary>
    [Flags]
    public enum SWP : uint {
      NOSIZE = 0x0001,
      NOMOVE = 0x0002,
      NOZORDER = 0x0004,
      NOREDRAW = 0x0008,
      NOACTIVATE = 0x0010,
      DRAWFRAME = 0x0020,
      FRAMECHANGED = 0x0020,
      SHOWWINDOW = 0x0040,
      HIDEWINDOW = 0x0080,
      NOCOPYBITS = 0x0100,
      NOOWNERZORDER = 0x0200,
      NOREPOSITION = 0x0200,
      NOSENDCHANGING = 0x0400,
      DEFERERASE = 0x2000,
      ASYNCWINDOWPOS = 0x4000
    }

    // SetWindowPos hwndInsertAfter special values
    // Must cast to IntPtr
    public const Int32 HWND_TOPMOST = -1;
    public const Int32 HWND_NOTOPMOST = -2;

    // http://msdn.microsoft.com/en-us/library/windows/desktop/ms633545(v=vs.85).aspx
    [DllImport("user32.dll", EntryPoint = "SetWindowPos")]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool SetWindowPos(
      [In] IntPtr hWnd,
      [In] IntPtr hWndInsertAfter,
      Int32 X, Int32 Y, Int32 cx, Int32 cy,
      SWP Flags);

    internal static void Main() {
      Process[] ps = Process.GetProcessesByName("notepad");
      foreach (Process p in ps) {
        Console.WriteLine("TopMost");
        MakeTopMost(p.MainWindowHandle);
      }
      Thread.Sleep(10000);
      foreach (Process p in ps) {
        Console.WriteLine("Not TopMost");
        RemoveTopMost(p.MainWindowHandle);
      }
      Console.WriteLine("...end");
      Console.ReadLine();
    }

    private static void MakeTopMost(IntPtr targetHwnd) {
      const SWP flags = SWP.NOSIZE | SWP.NOMOVE;
      SetWindowPos(targetHwnd, (IntPtr)HWND_TOPMOST, 0, 0, 0, 0, flags);
    }

    private static void RemoveTopMost(IntPtr targetHwnd) {
      const SWP flags = SWP.NOSIZE | SWP.NOMOVE;
      SetWindowPos(targetHwnd, (IntPtr)HWND_NOTOPMOST, 0, 0, 0, 0, flags);
    }
  }
}

Message Removed

2-Jul-12 10:48

N_tro_P

2-Jul-12 10:48

Message Removed

Re: Modify Top most

Alan N3-Jul-12 11:03

Alan N

3-Jul-12 11:03

Colin,
In the following method is there something missing as I don't see how _hWnd1 is set.

private void StartOtherProcesses()
        {
            Process.Start(APP_1);
 
            SetWindowPos(_hWnd1, HWND_NOTOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE | SWP_SHOWWINDOW);
        }

Assuming there is some missing code, i.e. SetHwnd(), have you checked that the GetWindowsHandler method does actually get a non zero handle. Handle creation will be some time after process start and it not uncommon for Process.MainWindowHandle to be IntPtr.Zero for several hundred milliseconds even after Process.WaitForInputIdle() has returned (despite what MSDN says!).

By the way, I have verified by reading the extended style bits with GetWindowLong, that SetWindowPos will remove the WS_EX_TOPMOST style from a maximized topmost window.

Alan.

modified 3-Jul-12 21:00pm.

Re: Modify Top most

Abhinav S2-Jul-12 16:15

Abhinav S

2-Jul-12 16:15

Alan N's solution is a very good one.

However, check if they have some modal / non-modal type if property which you can set in this control.
This will allow you to get away without writing sooo much more code.

Build your own survey - http://www.factile.net

Color Detection Using Emgu HSV

caoc72-Jul-12 7:12

caoc7

2-Jul-12 7:12

Please. Can help.... I need to filter the color red, Green and yellow in a image contained in the control Emgu.CV.UI.ImageBox.

Please can guide as I detect any of the three colors (red, green, yellow).
filter using HSV

modified 2-Jul-12 16:36pm.

Re: Color Detection Using Emgu

Dave Kreskowiak2-Jul-12 9:01

Dave Kreskowiak

2-Jul-12 9:01

Go through this article[^].

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Databinding a DataGridView not immediately available

Dewald2-Jul-12 4:11

Dewald

2-Jul-12 4:11

I have a form containing a DataGridView which I want to populate immediately upon creating the new form. The DataGridView is populated from a SQL query and I do it as follows:

using (SqlCommand mySqlCommand = new SqlCommand("SELECT * FROM MyTable", mySqlConnection))
{
    using (SqlDataReader mySqlDataReader = sqlCommand.ExecuteReader())
    {
        DataSet myDataSet = new DataSet();
        DataTable myDataTable = new DataTable();
        myDataSet.Tables.Add(myDataTable);
        myDataSet.Load(mySqlDataReader, LoadOption.PreserveChanges, myDataSet.Tables[0]);
        myDataGridView.DataSource = myDataSet.Tables[0];
    }
}

myDataGridView.AutoResizeColumns(DataGridViewAutoSizeColumnsMode.AllCells);
foreach(DataGridViewRow myRow in myDataGridView.Rows)
    // Do something with some of the values in the row

Now, the above code works perfectly except for the last two lines of code, which automatically resizes each column to fit the widest cell and which iterates through the DataGridView and does something with some of the values. The reason this won't work is because, by the time they are executed, the databinding for the DataGridView might not yet be finished.

One solution is to add

myDataGridView.DataBindingComplete += new DataGridViewBindingCompleteEventHandler(myDataGridView_DataBindingComplete);

And then put those lines of code inside the event handler.

For various reasons, it happens from time to time that I'd rather have those lines of code inside the original function that populates the form. I'd be quite happy to enter a loop that will wait for the data binding to complete before I continue but I don't know how. Any suggestions?

Re: Databinding a DataGridView not immediately available

Jasmine25012-Jul-12 5:46

Jasmine2501

2-Jul-12 5:46

Can't you just call the DataBind function explicitly?

like... myDataGridView.Databind();

Everything should be ready to go after that...

Re: Databinding a DataGridView not immediately available

Dewald2-Jul-12 6:30

Dewald

2-Jul-12 6:30

No, I believe that works only for Webforms, not for Winforms as is the case here.

I don't understand why that method is not available in winforms as it would have been the perfect solution for this problem of mine.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.