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The Bitmap object holds the file open for the lifetime of the object. The trick is to read the file yourself, create the bitmap from that stream, then close the stream.
FileStream fs = new FileStream(@"C:\bitmap.bmp");
Bitmap b = new Bitmap(fs);
fs.Close();
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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From MSDN,
You must keep the stream open for the lifetime of the Bitmap object.
Live Life King Size
Alomgir Miah
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I tried using the Filestream and closing it after creating the bitmap. It is working. Why must the stream remain open?
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If its working thats fine. But in some situations you might get Generic GDI+ error.
Check this
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfSystemDrawingBitmapClassctorTopic6.asp
So you should implement IDisposable interface and close the stream when Dispose Method is called.
I have written a BitmapHelper, hope this helps,
using System;
using System.IO;
using System.Drawing;
namespace Test.Controls
{
///
/// Summary description for BitmapHelper.
///
public class BitmapHelper: IDisposable
{
private Bitmap _bm;
private Icon _ic;
private MemoryStream _ms;
// Track whether Dispose has been called.
private bool disposed = false;
public BitmapHelper()
{
}
public void LoadBitmap(Stream sm)
{
Clear();
int len = (int) sm.Length;
byte[] buf = new byte[len];
sm.Read(buf,0,len);
_ms = new MemoryStream(buf);
_bm = (Bitmap) Image.FromStream(_ms);
}
public void LoadIcon(Stream sm)
{
Clear();
int len = (int) sm.Length;
byte[] buf = new byte[len];
sm.Read(buf,0,len);
_ms = new MemoryStream(buf);
_ic = new Icon(_ms);
}
public void LoadBitmap(string fileName)
{
FileStream fs = new FileStream(fileName,FileMode.Open,FileAccess.Read);
LoadBitmap(fs);
fs.Close();
}
public void LoadIcon(string fileName)
{
FileStream fs = new FileStream(fileName,FileMode.Open,FileAccess.Read);
LoadIcon(fs);
fs.Close();
}
public void LoadBitmap(object dbField)
{
Clear();
if (dbField != DBNull.Value)
{
byte[] buf = (byte[])dbField;
_ms = new MemoryStream(buf);
_bm = (Bitmap) Image.FromStream(_ms);
}
}
public void LoadIcon(object dbField)
{
Clear();
if (dbField != DBNull.Value)
{
byte[] buf = (byte[])dbField;
_ms = new MemoryStream(buf);
_ic = new Icon(_ms);
}
}
public void Clear()
{
if (_bm != null)
{
_bm.Dispose();
_bm = null;
}
if (_ic != null)
{
_ic.Dispose();
_ic = null;
}
if (_ms != null)
{
_ms.Close();
_ms = null;
}
}
// Implement IDisposable.
// Do not make this method virtual.
// A derived class should not be able to override this method.
public void Dispose()
{
Dispose(true);
// This object will be cleaned up by the Dispose method.
// Therefore, you should call GC.SupressFinalize to
// take this object off the finalization queue
// and prevent finalization code for this object
// from executing a second time.
GC.SuppressFinalize(this);
}
// Dispose(bool disposing) executes in two distinct scenarios.
// If disposing equals true, the method has been called directly
// or indirectly by a user's code. Managed and unmanaged resources
// can be disposed.
// If disposing equals false, the method has been called by the
// runtime from inside the finalizer and you should not reference
// other objects. Only unmanaged resources can be disposed.
private void Dispose(bool disposing)
{
// Check to see if Dispose has already been called.
if(!this.disposed)
{
// If disposing equals true, dispose all managed
// and unmanaged resources.
if(disposing)
{
// Dispose managed resources.
this.Clear();
}
// Call the appropriate methods to clean up
// unmanaged resources here.
// If disposing is false,
// only the following code is executed.
}
disposed = true;
}
public Bitmap Bitmap
{
get
{
return _bm;
}
}
public Icon Icon
{
get
{
return _ic;
}
}
}
}
Live Life King Size
Alomgir Miah
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Never have I had a problem with a Generic GDI error while using a Bitmap object. And I've created Bitmap objects from just about every imaginable source, be it a resource stream, external file, serialized network stream, XML data, SQL database, ... Come to think of it, I've never had a GDI+ error that wasn't caused by me doing something stupid, like trying to draw to the same object from two different threads at the same time.
If you have to keep the stream open, why does MSDN have an article that shows you how to get around this -> PRB: Image File Is Locked When You Set the PictureBox Image Property to a File[^]
The Bitmap class inherits from Image, so I fail to why you would have to keep the stream open for a Bitmap object and not for an Image object.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Closing the stream is working for me.
Thanks
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Straight from MSDN
Remarks
You must keep the stream open for the lifetime of the Bitmap object.
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfSystemDrawingBitmapClassctorTopic6.asp
This happens sometimes when the OnPaint tries to access the BitMap and
gets a null.
Live Life King Size
Alomgir Miah
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So it is...
But, like I said, never had a problem with it.
I fail to see why any Bitmap object (properly defined) would ever come back as null in the middle of OnPaint. I've never had it happen in any painting of any of my forms or controls.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Try adding a toolbar to your application. In each toolbar add a button.
Set an ImageList with BitMap streams. If you close the stream see what happens.
Live Life King Size
Alomgir Miah
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How many times do I have to tell you, I've never had a problem with it! I know about that little quirk! That's why I NEVER keep my Toolbar images in files. I keep them in Resources! I hate having open files laying around.
I keep as many images as I can in resources. I've even developed an ImageResources resource .DLL that holds my common images, including Toolbar buttons, in various sizes, masks, and transparencies. It's completely static so I don't have to instantiate the thing either.
Instead of deploying a bunch of image files along with my apps, I only deploy a sinlge .DLL. Now, all I have to do to set a Toolbar button image is:
SaveButton.Image = ImageResources.Buttons.Retrieve("Save 16x16 Trans.bmp")
Obviously, Retrieve() returns a Bitmap object. And "Look Ma!," no open file handles!
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Calm down man.
There is one more way, compile the images as embedded resources into a DLL, this way you have just one DLL. Still you have to open an stream.
FYI,
when you use resource files to embed images, a stream is opened internally. If you dont trust debug for yourself.
SO I am not fighting here, I am just trying to make my point.
Live Life King Size
Alomgir Miah
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Alomgir Miah wrote:
when you use resource files to embed images, a stream is opened internally.
Ya! Why do you think I said "no open file handles"?
You just made it sound like there was only one way to create images, using FromFile, and that EVERY Bitmap had to have an open stream associated with it. That's just not true.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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lol u r tough.
lets wrap it up.
Live Life King Size
Alomgir Miah
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I have to simulate a communication network over a city map. with features like route feasibilty study and viewing different components of the network .. please give me some guideline in this regard. how usefull C# would be in this regard.
haroon
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C# would be great for this. The extent that you want to do simulation for would vary based on complexity but here is my first design thought off the top of my head:
1) You have a 'controller' form which displays your network topography -- nice and graphic etc. probably using the US map as background image and controls marking the nodes and something unique for router locations etc.
2) You will need a network stub abstract class which handles the basics such as number of hops to destination, avg hop delay, bandwidth between hops etc.
3) You would inherit the abstract class defining these variables for each specific location. Each abstract class would be represented by theUI node point.
4) Included in the abastract class would be Send(), Receive(), and RoundTrip() calls that do all of the math and lag computations to handle one-way and round-trip calls into that node. (ie. sending a 10-packet message from Home() to SanFrancisco() for example.)
If each node handle computations and also inherits MyCustomControl (which is the visual stuff on the screen) then when you mouse over the control it can pull up latest transmission results (lag time, roundtrip time, simulated ping, etc.)
Sounds like a really cool project.
There are 10 kinds of people in the world.
Those that read binary...
...and those who don't.
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Hi!
I have to read a text file which can have text in languages like french, spanish etc.
and write the text to another text file.
When i use the StreamReader and StreamWriter with Encoding as Unicode i miss all the accented characters somehow.
Help will be appreciated 
Best Wishes
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I use an italian-localized machine, and I never found this kind of problem... try to read/write the file char-by-char, using BinaryReader.ReadChar() BinaryWriter.Write((char)yourChar)). I believe this way will work.
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I Used "Encoding.Default" while reading the file and it worked.
I like your way also and i'll be trying it too..
Thank You 
Best Wishes
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Hello,
Is there a way of placing an event inside the DataGrid on leaving a particular cell, and an event on the Column (for example TextChanged).
Mine grid is: dataGridRevenues
mine table style: styleLotYields
Thank you
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//
//Member Variables
//
int currentGridColumn = 0;
int currentGridRow = 0;
//
//Wire Up Events
//
this.dataGridDataEntrySheet.CurrentCellChanged += new EventHandler(this.OnGridCurrentCellChanged);
foreach( DataGridTextBoxColumn dataGridTextBoxColumn in this.dataGridTableStyle.GridColumnStyles )
{
dataGridTextBoxColumn.TextBox.TextChanged += new EventHandler(this.GridTextBoxTextChanged);
}
private void OnGridCurrentCellChanged(object sender, EventArgs e)
{
DataGridCell dataGridCell = this.dataGridDataEntrySheet.CurrentCell;
//Update Member Variables
this.currentGridRow = dataGridCell.RowNumber;
this.currentGridColumn = dataGridCell.ColumnNumber;
}
private void GridTextBoxTextChanged(object sender, EventArgs e)
{
if ( this.currentGridRow = 3 && this.currentGridColumn == 5 )
{
//Do some stuff
}
else if ( ... )
{
...
}
...
}
Live Life King Size
Alomgir Miah
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Thank you very much
It helped a lot.
Another Question: If I have a column in a datagrid, with
MapingName = "Quantity"
How can I go through each cell for this particular column.
Thank you again
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If you want the values, then loop through the DataSource, its DataTable I guess in your case.
Please modify the code below
CurrencyManager cm = (CurrencyManager)this.BindingContext[this.dataGrid1.DataSource];
int rowCount = cm.Count;
//assumes datasource is a datatable... looping all the values
int colCount = ((DataTable)this.dataGrid1.DataSource).Columns.Count;
for(int row = 0; row < rowCount; row++)
{
for(int col = 0; col < colCount; col++)
{
object cellValue = this.dataGrid1[row, col];
Console.Write(cellValue.ToString() + " ");
}
}
Live Life King Size
Alomgir Miah
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Thank you,
unfortunatelly the datasource is DataView, and it has no Column definition.
Thank you again.
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It does not matter what the datasource is. CurrencyManager only expects the DataSource to implement IList interface which both DataTable and DataView does.
So please modify the code and use it.
Live Life King Size
Alomgir Miah
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I have a little problem with a small C# Applikation that executes DTS. I don't know if this is the right Newsgroup. First of all here is what the Applikation should do.
A FileWatcherObject is monitoring a Directory for new CSV files. If there are new Files, the files will be added to an hash-table with key and filename. A timer objekt looks every 10 Seconds for Files in the hash-table and starts a DTS-Package for the first 20 Files of the hash-table. The applikation works fine, but after 2300 files i get an error from the DataPump task 80040428. This seems to be an connection problem. all other files after that error will fail too. Is it possible to change the applikation to avoid this error ? Here is the source (windows service)
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.IO;
using System.ServiceProcess;
using System.Configuration;
using System.Runtime.InteropServices;
using Microsoft.SqlServer.DTSPkg80;
namespace xMonitoringService
{
public class xMonitoringService : System.ServiceProcess.ServiceBase
{
/// <summary>
/// Erforderliche Designervariable.
/// </summary>
private System.ComponentModel.Container components = null;
public PackageClass package;
public int count;
public int gsmtcount;
public Hashtable myHT;
private System.Timers.Timer timer1;
public string serverName;
public string userName;
public string password;
public string packageName1;
public string packageName2;
public string packageName3;
public string filter1;
public string filter2;
public string filter3;
string directoryToMonitor;
FileSystemWatcher watcher;
public xMonitoringService()
{
// Dieser Aufruf ist für den Windows Komponenten-Designer erforderlich.
InitializeComponent();
// TODO: Initialisierungen nach dem Aufruf von InitComponent hinzufügen
}
// Der Haupteinstiegspunkt für den Vorgang
static void Main()
{
System.ServiceProcess.ServiceBase[] ServicesToRun;
// Innerhalb eines Prozesses können mehrere Dienste ausgeführt werden. Sie können einen
// Dienst zu diesem Prozess hinzufügen, indem Sie die folgende Zeile ändern,
// um ein zweites Dienstobjekt zu erstellen. Beispiel:
//
// ServicesToRun = new System.ServiceProcess.ServiceBase[] {new Service1(), new MySecondUserService()};
//
ServicesToRun = new System.ServiceProcess.ServiceBase[] { new xMonitoringService() };
System.ServiceProcess.ServiceBase.Run(ServicesToRun);
}
/// <summary>
/// Erforderliche Methode für die Designerunterstützung.
/// Der Inhalt der Methode darf nicht mit dem Code-Editor geändert werden.
/// </summary>
private void InitializeComponent()
{
this.timer1 = new System.Timers.Timer();
components = new System.ComponentModel.Container();
((System.ComponentModel.ISupportInitialize)(this.timer1)).BeginInit();
this.timer1.Enabled = true;
this.timer1.Interval = 10000;
this.timer1.Elapsed += new System.Timers.ElapsedEventHandler(this.timer1_Elapsed);
this.ServiceName = "xMonitoringService";
count=0;
gsmtcount=0;
myHT = new Hashtable();
serverName = System.Configuration.ConfigurationSettings.AppSettings["serverName"];
userName = System.Configuration.ConfigurationSettings.AppSettings["userName"];
password = System.Configuration.ConfigurationSettings.AppSettings["password"];
packageName1 = System.Configuration.ConfigurationSettings.AppSettings["packageName1"];
packageName2 = System.Configuration.ConfigurationSettings.AppSettings["packageName2"];
packageName3 = System.Configuration.ConfigurationSettings.AppSettings["packageName3"];
directoryToMonitor = System.Configuration.ConfigurationSettings.AppSettings["directoryToMonitor"];
filter1 = System.Configuration.ConfigurationSettings.AppSettings["filter1"];
filter2 = System.Configuration.ConfigurationSettings.AppSettings["filter2"];
filter3 = System.Configuration.ConfigurationSettings.AppSettings["filter3"];
((System.ComponentModel.ISupportInitialize)(this.timer1)).EndInit();
}
/// <summary>
/// Die verwendeten Ressourcen bereinigen.
/// </summary>
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
/// <summary>
/// Führen Sie die Vorgänge aus, um den Dienst zu starten.
/// </summary>
protected override void OnStart(string[] args)
{
EventLog.WriteEntry("xMonitoringService","On Start");
SetupWatcher();
this.timer1.Enabled = true;
this.timer1.Start();
// TODO: Fügen Sie hier Code hinzu, um Ihren Dienst zu starten.
}
/// <summary>
/// Beenden Sie den Dienst.
/// </summary>
protected override void OnStop()
{
//Disable the watcher
watcher.EnableRaisingEvents = false;
this.timer1.Enabled = false;
this.timer1.Stop();
myHT.Clear();
myHT = null;
serverName= null;
userName= null;
password= null;
packageName1= null;
packageName2= null;
packageName3= null;
filter1= null;
filter2= null;
filter3= null;
directoryToMonitor= null;
EventLog.WriteEntry("xMonitoringService","On Stop");
// TODO: Hier Code zum Ausführen erforderlicher Löschvorgänge zum Anhalten des Dienstes einfügen.
}
private void SetupWatcher()
{
// Create a new FileSystemWatcher and set its properties.
watcher = new System.IO.FileSystemWatcher();
watcher.Path = directoryToMonitor;
//Watch for changes in FileName
watcher.NotifyFilter = NotifyFilters.FileName;
//Watch for all files.
watcher.Filter = "";
//Add event handlers.
watcher.Created += new FileSystemEventHandler(OnCreated); //Begin watching
watcher.EnableRaisingEvents = true;
}
// Define the event handlers.
public void OnCreated(object source, FileSystemEventArgs e)
{
// Specify what is done when a file is created.
//Pass in the path of the file to the DTS Package
myHT.Add(e.Name.ToString(),e.FullPath.ToString());
//ExecutePackage(e.Name,e.FullPath);
}
private void timer1_Elapsed(object sender,System.Timers.ElapsedEventArgs e)
{
IDictionaryEnumerator myEnumerator = myHT.GetEnumerator();
try
{
while ( myEnumerator.MoveNext() && count < 20)
{
if(File.Exists(myEnumerator.Value.ToString()))
{
ExecutePackage(myEnumerator.Key.ToString(),myEnumerator.Value.ToString());
count++;
myHT.Remove(myEnumerator.Key);
gsmtcount++;
}
}
if(myHT.Count == 0)
{
myHT.Clear();
myHT = new Hashtable();
}
count=0;
myEnumerator = null;
}
catch(System.Exception ex)
{
EventLog.WriteEntry("xMonitoringService","Error Message :" + ex.Message + " Stack Trace : " + ex.StackTrace + ex.Source);
}
finally
{
if(myHT.Count == 0)
{
myHT.Clear();
myHT = null;
myHT = new Hashtable();
}
myEnumerator = null;
}
}
public void ExecutePackage(string gv_fileName, string gvFullFileName)
{
try
{
package = new PackageClass();
UCOMIConnectionPointContainer CnnctPtCont = (UCOMIConnectionPointContainer) package;
UCOMIConnectionPoint CnnctPt;
PackageEventsSink PES = new PackageEventsSink ();
Guid guid = new Guid("10020605-EB1C-11CF-AE6E-00AA004A34D5"); // UUID of PackageEvents Interface
CnnctPtCont.FindConnectionPoint(ref guid, out CnnctPt);
int iCookie;
CnnctPt.Advise(PES, out iCookie);
object pVarPersistStgOfHost = null;
//Retrieve global settings from the Configuration File
string packageName="";
if (gv_fileName.IndexOf(filter1)!= -1)
{
packageName = packageName1;
}
if (gv_fileName.IndexOf(filter2)!= -1)
{
packageName = packageName2;
}
if (gv_fileName.IndexOf(filter3)!= -1)
{
packageName = packageName3;
}
if (packageName != "")
{
package.LoadFromSQLServer(serverName,userName, password,DTSSQLServerStorageFlags.DTSSQLStgFlag_Default, null, null, null, packageName, ref pVarPersistStgOfHost);
//Loop through all the Global variables and remove the
//variables that are of type string
foreach(GlobalVariable global in package.GlobalVariables)
{
if (global.Name == "gv_FileFullName")
{
package.GlobalVariables.Remove(global.Name);
}
if (global.Name == "gv_fileName")
{
package.GlobalVariables.Remove(global.Name);
}
}
//Read all the global variables that are of type string
package.GlobalVariables.AddGlobalVariable("gv_FileFullName",gvFullFileName);
package.GlobalVariables.AddGlobalVariable("gv_fileName",gv_fileName);
package.Execute();
package.UnInitialize();
package = null;
CnnctPt.Unadvise(iCookie);
}
}
catch(System.Runtime.InteropServices.COMException ex)
{
EventLog.WriteEntry("xMonitoringService","Error Code : " + ex.ErrorCode + "Error Message :" + ex.Message + " Stack Trace : " + ex.StackTrace + ex.Source);
}
catch(System.Exception ex)
{
EventLog.WriteEntry("xMonitoringService", "Error Message :" + ex.Message + " Stack Trace : " + ex.StackTrace + ex.InnerException +" "+ex.TargetSite);
}
finally
{
package.UnInitialize();
package = null;
}
}
public class PackageEventsSink : DTS.PackageEvents
{
public void OnQueryCancel(string EventSource, ref bool pbCancel)
{
EventLog.WriteEntry("xMonitoringService"," In OnQueryCancel: Event Source: " + EventSource);
pbCancel = false;
}
public void OnStart(string EventSource)
{
EventLog.WriteEntry("xMonitoringService"," In OnStart: Event Source: " + EventSource);
}
public void OnProgress(string EventSource, string ProgressDescription, int PercentComplete, int ProgressCountLow, int ProgressCountHigh)
{
EventLog.WriteEntry("xMonitoringService"," In OnProgress: Event Source: " + EventSource + " Progress Description : " + ProgressDescription +
" PercentComplete : " + PercentComplete +
" ProgressCountLow : " + ProgressCountLow +
" ProgressCountHigh : " + ProgressCountHigh);
}
public void OnError(string EventSource, int ErrorCode, string Source, string Description, string HelpFile, int HelpContext, string IDofInterfaceWithError, ref bool pbCancel)
{
EventLog.WriteEntry("xMonitoringService"," In OnError: Event Source: " + EventSource + " Error Code : " + ErrorCode.ToString() + " Source : " + Source.ToString()+
" Description : " + Description + " HelpFile : " +
HelpFile + " HelpContext : " + HelpContext +
" InterfaceError " + IDofInterfaceWithError);
pbCancel = false;
}
public void OnFinish(string EventSource)
{
EventLog.WriteEntry("xMonitoringService", "In OnFinish");
}
}
}
}
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