Datagrid Binding to an Object - C# Discussion Boards

Johnny Hooyberghs6-Nov-05 4:33

6-Nov-05 4:33

Yeah, I was deriving from CheckBox and i think that was the problem. Now I'm deriving from usercontrol and it works like it supposed to.

Thanks anyways

Custom Controls

XeoN-Kc6-Nov-05 1:53

XeoN-Kc

6-Nov-05 1:53

I'm trying to write a sliding panel custom control. As regards the component sliding etc it is all ok. However, during design mode the V.S. doesn't let me place controls inside the panel. It places them on top of the panel, not into it. Can any one help out on this.

Best Regards Cool | :cool:

Re: Custom Controls

Johnny Hooyberghs6-Nov-05 2:28

Johnny Hooyberghs

6-Nov-05 2:28

Try deriving your custom control class from System.Windows.Forms.Panel instead of System.Windows.Forms.UserControl

Hope this is what you are looking for...
Greatings,
Johnny

Re: Custom Controls

mav.northwind6-Nov-05 2:31

mav.northwind

6-Nov-05 2:31

Did you set ControlStyles.ContainerControl style on your control?
(using Control.SetStyle())

Regards,
mav

capture and save image

mwallon6-Nov-05 1:12

mwallon

6-Nov-05 1:12

Hi,
I'm building a small application where I like to capure a part of the application screen and save it as a image.

Does anyone know of any tutorials o similiar about this??

The part I like capture is filled with a flash application if that will make it any difference.

Best regards
Magnus

Re: capture and save image

Heath Stewart6-Nov-05 6:26

Heath Stewart

6-Nov-05 6:26

If you search for screen capture[^] in the article search box at the top of every page right under the Code Project logo you can find many helpful articles and sample code.

This posting is provided "AS IS" with no warranties, and confers no rights.

Software Design Engineer
Developer Division Customer Product-lifecycle Experience
Microsoft

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access data in dataset dependent on selected combobox value

CandyMe6-Nov-05 0:14

CandyMe

6-Nov-05 0:14

Question please

I'd like to access data from database using dataset dependent on the
selectedValue in combobox.

My combobox's displays displayMember FieldName,
based on its valueMember fieldId,
i'd like be able to access the FieldAddress
which are all in Fields Table.

thank you!

Blush | :O

I wanna have something like this, except it doesn't return the whole row but just the Address:

<br />
 // Declare a data row to hold the selected customer's record.<br />
   DataRow drSelectedCustomer;<br />
   drSelectedCustomer = <br />
      dsNorthwind1.Customers.FindByCustomerID(SelectedCustomerID);

thank you again

Gerri

Datagrid Binding to an Object

wgroves5-Nov-05 20:13

wgroves

5-Nov-05 20:13

I'm really struggling trying to bind a Datagrid to a collection of objects. I understand that for each public property of the objects in the collection, a column will be displayed. But I don't want to display a column for all of the public properties, just some of them. And I also want to add columns to the datagrid for things like an image that is associated with one of the properties.

How do you hide columns when binding to objects?

How do you add columns to a datagrid when it is bound to a collection of objects?

Any help would be greatly appreciated!

Thanks

Warwick

"I hear they've even got the internet on Computers now." - Homer Simpson

Re: Datagrid Binding to an Object

J4amieC6-Nov-05 0:31

J4amieC

6-Nov-05 0:31

If you databind a datagrid to a list of objects, it will create a column for each property as you said.

However, if you first create a DataGridTableStyle and add to it the DataGridColumnStyle objects that you want then only those columns will be shown.

This can be done directly in the designer.

Re: Datagrid Binding to an Object

wgroves6-Nov-05 10:13

wgroves

6-Nov-05 10:13

Thanks! I've just had a look at TableStyles/ColumnStyles and will try it today.

Cheers

Warwick Smile | :)

"I hear they've even got the internet on Computers now." - Homer Simpson

Re: Datagrid Binding to an Object

n10sive10-Nov-05 12:15

n10sive

10-Nov-05 12:15

Take a look at ITypedList. Adding it to your collection allows you to create property descriptors. The Datagrid will respect this list. This is more "class friendly" to implementers and they won't have to use table styles to get rid of the unfriendly stuff.

Zooming in/out of Pictures in a PictureBox Control

E6AD5-Nov-05 19:57

E6AD

5-Nov-05 19:57

Hi,

Can someone please tell me how can I zoom in and out of an image that is displayed in a picture box control???

Please Help...

Thanks,
E.A.

Re: Zooming in/out of Pictures in a PictureBox Control

Jon Rista8-Nov-05 7:21

Jon Rista

8-Nov-05 7:21

As far as I know, the picturebox does not directly support such a thing. You would have to write custom code to scale the image from an offscreen source image, then reset the picture box .Image property. You could also write your own simple custom control that intrinsically supports image scaling, which would be more elegant and probably smoother.

Reseting Object Arrays With New Length

budidharma5-Nov-05 17:11

budidharma

5-Nov-05 17:11

Here's an example of what I'm dealing with:

int[] myints = new int { 1, 2, 3 };

foreach(int i in myints)
{
Console.Write(i.ToString()); // WORKS PERFECT.
}
Console.Write(myints.Length); // Displays 3.

int[] newints = new int { 1, 2, 3, 4 };
myints = newints;

foreach(int i in myints)
{
Console.Write(i.ToString()); // WORKS PERFECT.
}
Console.Write(myints.Length); // Displays 4

int[] reallynewints = new int { 1, 2 };
myints = reallynewints;
foreach(int i in myints)
{
Console.Write(i.ToString()); // THROWS NULLEXCEPTIONERROR
}
Console.Write(myints.Length); // Displays 2

So, here's the problem I'm having. When you set an array equal to an array with less elements, the Length property is updated, but there is still a null reference inside the array to an unused array element. You can fix the problem by overloading the Int.ToString() method with a try-catch block to avoid the error, but that's just a patch. How can I reset the array completely, so there is not a null reference to unused elements?

Re: Reseting Object Arrays With New Length

leppie5-Nov-05 18:53

leppie

5-Nov-05 18:53

budidharma wrote:
foreach(int i in myints)
{
Console.Write(i.ToString()); // THROWS NULLEXCEPTIONERROR
}
Console.Write(myints.Length); // Displays 2

How it display 2 if you got a NullReference exception?

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Re: Reseting Object Arrays With New Length

budidharma5-Nov-05 19:09

budidharma

5-Nov-05 19:09

The way I just wrote that, it wouldn't cause the error would occur first. If you put the myints.Length line before the foreach statement, it will display the correct length.

Re: Reseting Object Arrays With New Length

S. Senthil Kumar6-Nov-05 19:57

S. Senthil Kumar

6-Nov-05 19:57

budidharma wrote:
When you set an array equal to an array with less elements, the Length property is updated, but there is still a null reference inside the array to an unused array element.

That can't be true. Arrays being reference types, everytime you assign something to myints, the earlier reference is overwritten with the new one. So myints = reallynewints maeks myints point to the reallynewints array now.

The source of your problem is somewhere else. Are you doing something to the myints array after the assignment but before the foreach statement?

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

Re: Reseting Object Arrays With New Length

Jon Rista8-Nov-05 7:19

Jon Rista

8-Nov-05 7:19

Before I answer, how many times does the last foreach loop? Does it loop twice, then give the nullexception? Or does it immediately give the nullexception on thefirst iteration?

get serial number of cd in c# ?

hdv2125-Nov-05 13:53

hdv212

5-Nov-05 13:53

hi i am c# programmer and thank you for your site . it is best programming site .
how to get serial number of cd in c# ?
please help me ...
thanks
hdv212@yahoo.com

hdv212@yahoo.com

context menu on service notifyicon

g00fyman5-Nov-05 13:09

g00fyman

5-Nov-05 13:09

hi all,

am using .NET 2.0 and have a service that has a notifyicon, the service runs as LocalSystem and is allowed to interact with desktop.

when the service starts the tray icon appears, (and the service spawns a form thread, successfully) but i dont have a contextmenu when i click the icon, i have put a click event on the icon as well to restore a form that the service also starts and the event doesnt appear to be firing.

is this a problem, with it running as localsystem ? or have i completely gone pear shaped with something.

<br />
private void notifyIcon_MouseClick(object sender, MouseEventArgs e)<br />
    {<br />
      MessageBox.Show("hey");<br />
    }<br />
<br />
    private void notifyIcon_Click(object sender, EventArgs e)<br />
    {<br />
      MessageBox.Show("hey");<br />
      if (this.proxyServer.Visible == false)<br />
      {<br />
        this.proxyServer.Visible = true;<br />
        this.proxyServer.WindowState = FormWindowState.Normal;<br />
      }<br />
    }<br />

neither of these events are showing a messagebox

kind regards,
g00fy

Overloading Index Operator

budidharma5-Nov-05 12:05

budidharma

5-Nov-05 12:05

Is it possible in C#?
I have a class, Hand. It contains an Array of cards. I have defined a property in the array which returns the array of cards that it contains, but it makes for convoluted syntax:
Player.Cards.Card[1];
Where Player.Cards refers to the "hand" a player holds.

If my Hand class looks something like:

public class Hand
private Card[] m_Hand;

public Hand(params Card[] cards)
{
m_Hand = cards;
}

public Card[] Cards
{
get
{
return m_Hand;
}
}
}

Can I simply overload the index operator for my Hand class and get rid of the Cards property?

So I could do something like:
Player.Cards[0];
Would refer to: Player.Cards.m_Hand[0];

That make sense?

As always, thanks!

Re: Overloading Index Operator

Heath Stewart5-Nov-05 12:39

Heath Stewart

5-Nov-05 12:39

Yes you can, using this as a property name and optionally using the IndexerNameAttribute to get it a name (for some languages like VB.NET have to refer to the indexer while C# doesn't) other than "Item":

public class Hand
{
  // ...
  [System.Runtime.CompilerServices.IndexerName("Card")] // Optional
  public Card this[int index]
  {
    get { return m_Hand[index]; }
  }
  // ...
}

This posting is provided "AS IS" with no warranties, and confers no rights.

Software Design Engineer
Developer Division Customer Product-lifecycle Experience
Microsoft

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dataGrid - change background color of cell on RUN TIME

dataminers5-Nov-05 11:22

dataminers

5-Nov-05 11:22

Hi,

I can't change the background color of a specific cells in a datagrid on RUN TIME. I find a article but this article works on DESIGN TIME.

My problem is: For example user select a color on the colorDialog and i want to change current cell color. Not all row, just one cell change it.

For example: select green, ROW#1 CELL#5 is green
select red, ROW#2 CELL#5 is red
select blue, ROW#3 CELL#5 is blue ....

Please help me! Pleseeeeeeeeeeeeeeeeeeee...

I try from 3 day. Cry | :((

BORAN

Re: dataGrid - change background color of cell on RUN TIME

Heath Stewart5-Nov-05 12:42

Heath Stewart

5-Nov-05 12:42

See http://www.codeproject.com/csharp/custom_datagridcolumnstyl.asp[^] for a good example of changing a cell color based on the content of the cell, though you could base the color on whatever you want. The idea is to derive your own class from DataGridTableStyle and use that as a style for a particular column using the DataGrid.TableStyles property documented at http://msdn.microsoft.com/library/en-us/cpref/html/frlrfsystemwindowsformsdatagridclasstablestylestopic.asp[^], which shows a good example of how to use table styles with a Windows Forms DataGrid.

This posting is provided "AS IS" with no warranties, and confers no rights.

Software Design Engineer
Developer Division Customer Product-lifecycle Experience
Microsoft

[My Articles] [My Blog]

Re: dataGrid - change background color of cell on RUN TIME

dataminers5-Nov-05 12:50

dataminers

5-Nov-05 12:50

This article on Design Time. I want to change on Run Time. Yes, i can solve it but some new problem. I can't understand how to add component class. I add ColumnStyle.cs but error on ColumnStyle() function.

Thanks alot

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