Re: compare the contents inside ArrayList - C# Discussion Boards

Using WINAPI methods...

Amirjalaly9-Dec-03 23:59

Amirjalaly

9-Dec-03 23:59

how we can use winapi methods in c#

regards' Amir Jalaly

Re: Using WINAPI methods...

Heath Stewart10-Dec-03 3:27

Heath Stewart

10-Dec-03 3:27

Nick Seng already gave you a helpful link below. P/Invoke uses the DllImportAttribute on external function declarations. You should read the SDK documentation for the System.Runtime.InteropServices namespace elements, include the MarshalAsAttribute which helps the framework marshal parameters (when necessary) for native functions and COM interop.

-----BEGIN GEEK CODE BLOCK-----
Version: 3.21
GCS/G/MU d- s: a- C++++ UL@ P++(+++) L+(--) E--- W+++ N++ o+ K? w++++ O- M(+) V? PS-- PE Y++ PGP++ t++@ 5 X+++ R+@ tv+ b(-)>b++ DI++++ D+ G e++>+++ h---* r+++ y+++
-----END GEEK CODE BLOCK-----

Shut down the computer...

Amirjalaly9-Dec-03 22:44

Amirjalaly

9-Dec-03 22:44

How we can shut down the computer programically?
or Log off?

Regards' Amir Jalaly

Re: Shut down the computer...

Nick Seng9-Dec-03 22:50

Nick Seng

9-Dec-03 22:50

ExitWindowsEx WinAPI function

"if you vote me down, I shall become more powerful than you can possibly imagine" - Michael P. Butler.

Support Bone

Re: Shut down the computer...

Amirjalaly9-Dec-03 23:49

Amirjalaly

9-Dec-03 23:49

I can not find this method and when i write method name in code i recieved compile error

Regards' Amir JAlaly

Re: Shut down the computer...

Nick Seng10-Dec-03 0:19

Nick Seng

10-Dec-03 0:19

It's a function in the User32.lib API. Use P/Invoke to call this function from a C# Application.

Read more about P/Invoke here[^]

and ExitWindowsEx here[^]

"if you vote me down, I shall become more powerful than you can possibly imagine" - Michael P. Butler.

Support Bone

compare the contents inside ArrayList

azusakt9-Dec-03 22:25

azusakt

9-Dec-03 22:25

Hi, All.
I have a question about comparing the contents of ArrayList.
I use an arraylist to store up some strings, and the that arraylist is stored inside a new arraylist.
e.g.
ArrayList final= new ArrayList();
//--- loop ---//
ArrayList str = new ArrayList();
str.Add("xxx"); // storing string
str.Add("yyy");
.....

final.Add(str);
//-------------//

The "final" arraylist collects all "str" arraylist, and now I want to check whether the "final" contains one arrayList. It seems doesn't work, am I do it worng??
I use :
if(final.Contains(newstr)) // newstr is a new created arraylist
{
// do something here....
}

Please help~~

Re: compare the contents inside ArrayList

Nick Seng9-Dec-03 23:14

Nick Seng

9-Dec-03 23:14

Have you added newStr into final yet? If not, your expression will return false.

ArrayList.Contains function will only return true if you pass in the reference of an object that is within the arraylist. For example, if your code had been written like so:

....
ArrayList tempRef = str;
final.Add(str);
....

the expression final.Contains(tempRef) would return true.

HTH.

"if you vote me down, I shall become more powerful than you can possibly imagine" - Michael P. Butler.

Support Bone

Re: compare the contents inside ArrayList

azusakt10-Dec-03 14:55

azusakt

10-Dec-03 14:55

I don't know why still does work ?

in my program:
I store create an arraylist to store up the some string of ListView item data, and I assign that arraylist as ListViewItem.Tag

Finally, when I multiple selected the ListViewItem, I use a new ArrayList called "Final" to collect selected Item.Tag:

for(int i=0; i< List.Items.Count; i++)
{
  Final.Add( (ArrayList) List.Items[i].Tag );
}

I want to check if "Final" contains any Tags new ListView;

ArrayList selectedItems = Final;
if(selectedItems.Contains(Items[i].Tag))
     Items[i].BackColor = Color.Orange;

I have used debug window to check, they contains same data inside actually, but seems wrong data type; the selectedItems only shows that it contains "system.object", however, Items[i].Tag contains "System.Collections.ArrayList"??
Is it a mistake that I made?

Please help ~~ Thank you

Re: compare the contents inside ArrayList

Nick Seng10-Dec-03 15:57

Nick Seng

10-Dec-03 15:57

First of all, some suggestions.

this line:
Final.Add( (ArrayList) List.Items[i].Tag );
Don't bother casting the Tag object to arraylist as ArrayList Items are of the System.Object Class. What you are doing is casting from Object to Arraylist, and then back to object.

azusakt wrote:
I want to check if "Final" contains any Tags new ListView;

I'm not sure I understand this sentence. Do you mean that the you now have a different ListView? If so, you should remember that ArrayList.Contains checks for reference, not values. For example:

//a,b,c are ArrayLists
a.Add("123");
b.Add("123");
c.Add(a);

The expression c.Contains(b) would return false even thought a and b contains the same value, just because a and b not the same reference.

I hope I'm not confusing you

"if you vote me down, I shall become more powerful than you can possibly imagine" - Michael P. Butler.

Support Bone

How can i focus a perticular cell in DataGrid control

KRathor9-Dec-03 19:49

KRathor

9-Dec-03 19:49

Hello,

I want to focus a perticular cell in a datagrid control. Its not a difficult task, but i don't want to surf my time, so if anyone knows this thing, please reply soon.

Thanks.

Re: How can i focus a perticular cell in DataGrid control

Heath Stewart10-Dec-03 3:08

Heath Stewart

10-Dec-03 3:08

So you think posting a simple question to the forums is faster than looking at the properties and methods for the DataGrid class? DataGrid.CurrentCell should stick out like a sore thumb.

Re: How can i focus a perticular cell in DataGrid control

KRathor10-Dec-03 4:34

KRathor

10-Dec-03 4:34

Hello,

Infact, i already tried it. But, its not focusing on a perticular cell when i do this,

DataGrid.CurrentCell.RowNumber = RowNumber;
DataGrid.CurrentCell.ColumnNumber = ColumnNumber;

It gives me an exception. I want to focus a perticular cell during runtime.

Re: How can i focus a perticular cell in DataGrid control

Heath Stewart10-Dec-03 4:56

Heath Stewart

10-Dec-03 4:56

The property type (DataGridCell) is a struct, not a reference type, so you just can't change the properties/fields of it because you actually are changing the values for a copy of the DataGridCell. Instead, you must do the following:

DataGridCell cell = new DataGridCell(row, column);
// or simply instantiate, then set the properties, then finally...
dataGrid1.CurrentCell = cell;

This was also done in a similar way in the example code for the SDK documentation of the DataGrid.CurrentCell property.

Re: How can i focus a perticular cell in DataGrid control

11-Dec-03 7:12

Hay,

Thank u for your reply to my simple questions. Now, let me tell u my exact problem.

I have four columns in a datagrid. When i finishes my entries in a a perticular row and press Enter. By default the DataGrid creates a new empty row. I want to focus the second column cell of that new row whenever i press Enter.

I have already tested this,

DataGridCell cell = new DataGridCell(int rownum, int colnum);
DataGrid.CurrentCell = cell;

I tried this thing in a 'RowChanged' event of the dataset binded with that DataGrid.

Dataset.Table.RowChanged += new EventHandler(DataSet_RowChanged);

It creates Two or Three empty rows and then focus the last new line cell.

Try this thing, if you have understood my problem and reply soon.

Thanks.

Re: How can i focus a perticular cell in DataGrid control

Heath Stewart11-Dec-03 8:53

Heath Stewart

11-Dec-03 8:53

Because the new row isn't actually a row. Especially, the event handler you created on the DataSet won't work because a row hasn't been added until you actually start entering data for the new row (or edit an existing row) and commit it.

You might be interested in getting a spreadsheet-type control, such as the one from FarPoint Technologies[^].

How to Print a form with controls in C#

pahluwalia9-Dec-03 11:35

pahluwalia

9-Dec-03 11:35

Does anyone know an easy way to Print a form with controls in C# ?

Paul

Re: How to Print a form with controls in C#

Heath Stewart9-Dec-03 17:12

Heath Stewart

9-Dec-03 17:12

There's no easy way to do it. You'll have to P/Invoke many different native methods from the Gdi32.dll library, such as BitBlt, GetDeviceCaps, CreateCompatibleDC, CreateCompatibleBitmap, and SelectObject. Some others might be necessary, too. Just google for keywords like HDC, screen, printer, and bitblt. Most examples are in C++ but - with the power of P/Invoking - you should be able to do what you want.

Here's a few hints: you can get the HDC for a Graphics object by calling Graphics.GetHdc(). Both the Form.Paint and PrintDocument.PrintPage events pass a Graphics object in the second parameter (as a property). In the PrintDocument.PrintPage event, you can call Form.CreateGraphics() (actually inherited from the Control class) to get a Graphics object at that point.

Re: How to Print a form with controls in C#

Ruchi Gupta10-Dec-03 7:39

Ruchi Gupta

10-Dec-03 7:39

/****
Here is a sample form with a Print button and couple of controls. When you hit print button, it prints the form with the controls and the contents if any on the control.

To check it, start a new C# windows aplication project and replace Form1.cs with following contents.

Things to be noted are :-
Functions:
btnPrint_Click
CaptureScreen
printDocument1_PrintPage
Objects and declaration
[System.Runtime.InteropServices.DllImport("gdi32.dll")]
public static extern long BitBlt (IntPtr hdcDest, int nXDest, int nYDest, int nWidth, int nHeight, IntPtr hdcSrc, int nXSrc, int nYSrc, int dwRop);
private Bitmap memoryImage;

private System.Drawing.Printing.PrintDocument printDocument1;

If u have any questions, let me know.
Ruchi
****/
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

namespace WindowsApplication2
{
/// <summary>
/// Summary description for Form1.
/// </summary>
public class Form1 : System.Windows.Forms.Form
{
[System.Runtime.InteropServices.DllImport("gdi32.dll")]
public static extern long BitBlt (IntPtr hdcDest, int nXDest, int nYDest, int nWidth, int nHeight, IntPtr hdcSrc, int nXSrc, int nYSrc, int dwRop);
private Bitmap memoryImage;

private System.Windows.Forms.DateTimePicker dateTimePicker1;
private System.Windows.Forms.TextBox textBox1;
private System.Windows.Forms.Button btnPrint;
private System.Drawing.Printing.PrintDocument printDocument1;
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.Container components = null;

public Form1()
{
//
// Required for Windows Form Designer support
//
InitializeComponent();

//
// TODO: Add any constructor code after InitializeComponent call
//
}

/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}

#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.dateTimePicker1 = new System.Windows.Forms.DateTimePicker();
this.textBox1 = new System.Windows.Forms.TextBox();
this.btnPrint = new System.Windows.Forms.Button();
this.printDocument1 = new System.Drawing.Printing.PrintDocument();
this.SuspendLayout();
//
// dateTimePicker1
//
this.dateTimePicker1.Location = new System.Drawing.Point(48, 72);
this.dateTimePicker1.Name = "dateTimePicker1";
this.dateTimePicker1.TabIndex = 0;
this.dateTimePicker1.ValueChanged += new System.EventHandler(this.dateTimePicker1_ValueChanged);
//
// textBox1
//
this.textBox1.BackColor = System.Drawing.SystemColors.Info;
this.textBox1.Location = new System.Drawing.Point(32, 128);
this.textBox1.Name = "textBox1";
this.textBox1.Size = new System.Drawing.Size(160, 20);
this.textBox1.TabIndex = 1;
this.textBox1.Text = "textBox1";
//
// btnPrint
//
this.btnPrint.Location = new System.Drawing.Point(192, 216);
this.btnPrint.Name = "btnPrint";
this.btnPrint.TabIndex = 2;
this.btnPrint.Text = "Print";
this.btnPrint.Click += new System.EventHandler(this.btnPrint_Click);
//
// printDocument1
//
this.printDocument1.PrintPage += new System.Drawing.Printing.PrintPageEventHandler(this.printDocument1_PrintPage);
//
// Form1
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(292, 273);
this.Controls.AddRange(new System.Windows.Forms.Control[] {
this.btnPrint,
this.textBox1,
this.dateTimePicker1});
this.Name = "Form1";
this.Text = "Form1";
this.ResumeLayout(false);

}
#endregion

/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.Run(new Form1());
}
private void showmessage()
{
MessageBox.Show("Testing 123");
}
private void dateTimePicker1_ValueChanged(object sender, System.EventArgs e)
{
//MessageBox.Show("Testing 123");
showmessage();
//System.Console.WriteLine("Testing 123");
}

private void CaptureScreen()
{
Graphics mygraphics = this.CreateGraphics();
Size s = this.Size;
memoryImage = new Bitmap(s.Width, s.Height, mygraphics);
Graphics memoryGraphics = Graphics.FromImage(memoryImage);
IntPtr dc1 = mygraphics.GetHdc();
IntPtr dc2 = memoryGraphics.GetHdc();
BitBlt(dc2, 0, 0, this.ClientRectangle.Width, this.ClientRectangle.Height, dc1, 0, 0, 13369376);
mygraphics.ReleaseHdc(dc1);
memoryGraphics.ReleaseHdc(dc2);
}
private void printDocument1_PrintPage(System.Object sender, System.Drawing.Printing.PrintPageEventArgs e)
{
Font f = new Font("Arial",12);
e.Graphics.DrawString("Opetion Message if I want to be printed", f, Brushes.Black, 300, 50);
e.Graphics.DrawImage(memoryImage,75, 75);
}
private void btnPrint_Click(System.Object sender, System.EventArgs e)
{
CaptureScreen();
PrintDialog printDialog1 = new PrintDialog();
printDialog1.Document = printDocument1;

DialogResult result = printDialog1.ShowDialog();
if (result == DialogResult.OK)
{
printDocument1.Print();
}

//printDocument1.Print();
}
}
}

Re: How to Print a form with controls in C#

pahluwalia12-Dec-03 3:13

pahluwalia

12-Dec-03 3:13

what if the form's height is more than the screen height ?

And how can I print a DataGrid with scrolling items all to be displayed ?

Paul

ISynchronizeInvoke

LokiSD9-Dec-03 9:20

LokiSD

9-Dec-03 9:20

I have code which uses multi-threaded operations and am currently using ISyncronizeInvoke, with a Form to synchronize the threads and pass data along the windows message queue.

The problem occurs when an exception is thrown inside the Invoke()'d method, this exception is passed back down to the method that called the Invoke() command, and not inside the method that actually caused the exception.

Does anyone know if there is a way for me to keep the exceptions thrown inside the Invoke, where they are (so to speak)?
Or even a better way to synchronize the threads?

Thanks..

EDIT: Forgot to say, the main idea behind this is that I want to raise events from a thread, on my main process. So that when a thread has something that needs attention, an event is then raised on the main process, so that it can do something funky.

--
Rob Hutchinson.

Re: ISynchronizeInvoke

Heath Stewart9-Dec-03 9:49

Heath Stewart

9-Dec-03 9:49

Not unless you can modify the invoked method implementation, either by changing the original source or overriding a method and putting the base.Method call in a try-catch. Otherwise, just catch and ignore the exception when you call Invoke or handle the AppDomain.UnhandledException event.

Image Colour Depth Problem

Tristan Rhodes9-Dec-03 7:20

Tristan Rhodes

9-Dec-03 7:20

I have an ImageList that stores Icons pulled from the system. When a new file extention is looked up, the icon is pulled from the system, and compared with all the current icons through a pixel by pixel comparison.

The problem I have is that, the images stored in the imageList are stored at a different color depth to the one that comes fresh from the system.

I'd like to set the Colour Depth on the imagelist to that of the system, or alternatively, set the imported image colour depth to that of the image list.

However, I am lost as to how to do this.

Any help would be appreciated.

Cata

Re: Accessing variables from the code behind page

Heath Stewart9-Dec-03 6:34

Heath Stewart

9-Dec-03 6:34

Then as a previous user suggested, create a class that inherits from Page and make sure you change the base class in each of your code-behind source files to use that class. Each page should override the property (so make sure the property in the derivative class is marked as virtual) and return the string you want with each page.

Alternatively, if your pages are named correctly, you actually could use the Type name. In your user control, you could do something like:

string name = Page.GetType().FullName;
name = name.Substring(name.LastIndexOf('.') + 1);

...and name would contain the class name of the page. Of course, this would only work if your page class names matched up with what you want for your user control. It might work, but the first solution is a better object-oriented solution.

Note, too, that if you create a base Page class (that inherits from Page), you should probably also change your Web.config file so that it uses that page (in case a file has no code-behind source file). See the <pages> section, specifically the pageBaseType attribute.

FileStream question

Tim Kohler9-Dec-03 6:16

Tim Kohler

9-Dec-03 6:16

I'm trying to open a file for writing in a server process. I do not want any other process to be able to write to the file while I have it open, but I do want to allow other programs to read from it. Seems simple enough. I think I've done this with CFile in MFC. I'm getting a problem trying to use the .NET FileStream class. Can any of you shed light on why I'm getting a 'File is in use' IO exception with this:

try
{
String Nm = "c:\\testfile.txt";

//simulate the server opening the file for writing:
FileStream str = File.Open(Nm, FileMode.Append, FileAccess.Write, FileShare.Read);

//simulate some other process opening the file for reading: (exception thrown here)
FileStream sss = File.OpenRead(Nm);
}
catch (IOException e)
{
System.Console.WriteLine(e.Message);
}

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