Re: Append a property to existing control - C# Discussion Boards

1-Apr-08 0:00

How can add a property to a existing .NET control. For eg: Add a property "AllowNumbers" to textbox control.

Thanks

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J4amieC1-Apr-08 0:05

J4amieC

1-Apr-08 0:05

derive a new class from it and add your property

public class MyTextBox : TextBox
{
 public MyTextBox() : base()
 {
 }

 private bool allowNumbers = false;
 public bool AllowNumbers
 {
  get{ return this.allowNumbers; }
  set{ this.allowNumbers = value; }
 }
}

dan!sh 1-Apr-08 0:21

1-Apr-08 0:21

Thanks a lot.

I am facing one more issue.
I have created a user control, but when I add it to the form from the toolbox I get following code in the designer file:

this.usercontrol1 = new usercontrol.usercontrol();

instead of

this.usercontrol1 = new usercontrol();

This is causing build errors.

Any help with this ?

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stancrm1-Apr-08 0:23

stancrm

1-Apr-08 0:23

Put your control in the same namespace...

dan!sh 1-Apr-08 0:33

1-Apr-08 0:33

The form and the user control share the same namespace Confused | :confused:

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stancrm1-Apr-08 0:36

stancrm

1-Apr-08 0:36

What kind of error ?
The compiler returns an error message, if error comes.

dan!sh 1-Apr-08 0:40

1-Apr-08 0:40

Line of code giving error:

this.dataGridWrapper1 = new DataGridWrapper.DataGridWrapper();

error description:
The type name 'DataGridWrapper' does not exist in the type 'DataGridWrapper.DataGridWrapper'

DataGridWrapper is the namespace and also the class name for the usercontrol.

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stancrm1-Apr-08 0:44

stancrm

1-Apr-08 0:44

That means, there is something wrong with DataGridWrapper namespace or DataGridWrapper class. Not in usercontrol.
Please rename your namespace, not the same name with your class.
Then just put the right namespace. That means, in namespace "DataGridWrapper" there is no class with the name "DataGridWrapper"....

dan!sh 1-Apr-08 1:13

Intercepting calls to ServicedComponent

1-Apr-08 1:13

great it worked!!!
stupid me Smile | :)

probably i had confused .net by same names

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Roger Alsing31-Mar-08 23:57

Roger Alsing

31-Mar-08 23:57

Im well aware that there are a gazillion of AOP inspired samples out there that show how to intercept ContextBoundObject.
ServicedComponent inherits ContextBound, but none of those examples works when applied to SC.

Have anyone done this?
I pretty much only want to log parameters and do some basic serup when a method is called.

Blog: http://www.rogeralsing.com
Projects: http://www.puzzleframework.com

wrinting a query

Hum Dum31-Mar-08 23:57

31-Mar-08 23:57

A database having two tables, Company and Cust.
Company feilds : Cid, Cname
Cust Feilds: custId, custName, Cid(same as Company)

I bound the Company:Cname to a combobox,

I want to write a query like:

"select * from Cust where [Cid]= ???"

???=(here the Cid of selected Cname from comboBox)

how to get the corresponding Cid feild of combobox selected Cname??

dan!sh 1-Apr-08 0:08

1-Apr-08 0:08

Set Cid as the valuemember for the combo and Cname as the display member. Then the where clause will become - "where Cid = combobox.selectedvalue"

Hope it helps.

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Hum Dum1-Apr-08 0:38

1-Apr-08 0:38

Thanks for replying.

d@nish wrote:
where Cid = combobox.selectedvalue"

I also had tried this, but its giving error "Datatype mismatch in criteria exprssion"

Also when i debug the query, comboBox.SelectedValue gives the index value of selected item, not the Cid feild value from Company table.

any suggestion or link u can fwd me.

Eduard Keilholz1-Apr-08 0:35

Eduard Keilholz

1-Apr-08 0:35

assuming you've set the DataValueField member when databinding...

<br />
combobox.SelectedValue<br />

.: I love it when a plan comes together :.
http://www.zonderpunt.nl

Hum Dum1-Apr-08 0:44

1-Apr-08 0:44

Eduard Keilholz wrote:
assuming you've set the DataValueField member when databinding...

I had set the comboBox.DisplayMember = "Cname" (name of company)
comboBox.Valuemamber="Cid" (id of company)

but still not ok??

Eduard Keilholz wrote:
combobox.SelectedValue

dan!sh 1-Apr-08 1:28

1-Apr-08 1:28

this code works fine for me:

this.comboBox1.DataSource = this.dataGridWrapper1.table;
this.comboBox1.ValueMember = "ID";
this.comboBox1.DisplayMember = "DT";
:
:
:
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e) {
string s = this.comboBox1.SelectedValue.ToString();
}

I get the id corresponding to the selected dt

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Hum Dum1-Apr-08 2:12

1-Apr-08 2:12

thanks a lot.
I had set the sort property of combobox= true,
this is creating trouble.

But, why its creating the error. Any clue?

But still there is another problem,
When the query is giving error, it stops at fill method of DAdapter,

The exception is "Datatype mismatch in criteria expression"
I cheked the DB datatype, both are same in both column.
Do you know the reason.