C# Discussion Boards - CodeProject

Re: How to handle keydown/keypress/keyup for a label

16-Aug-04 0:04

hi,
your welcome.

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Nick Parker16-Aug-04 4:52

Nick Parker

16-Aug-04 4:52

You could write your own class that inherits from Control giving you access to the KeyDown, KeyPress, and KeyUp events or you could simply override the WndProc, watch for the appropriate windows messages and act accordingly.

- Nick Parker
My Blog | My Articles

Ignoring the version of C# dll assembly

ting66815-Aug-04 20:56

15-Aug-04 20:56

HI~

I have written an application using C#
There are some dlls. After a few day, I have updated some of the dlls(not in the same project of the orginial application). After I copy the new dll to the application directory and run it, runtime error occured. I know it is the dll version problem. So, can we ignore the version of the dll so that the application can be run without the runtime error? Or there is any other solution to solve the problem?

Thanks

sreejith ss nair15-Aug-04 21:20

15-Aug-04 21:20

hi,
try to check your AssemblyInfo.cs and make sure the version info.

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ting66815-Aug-04 23:48

15-Aug-04 23:48

Is this statement specify the assemblyVersion?

[assembly: AssemblyVersion("1.0.*")]

Can I change this to

[assembly: AssemblyVersion("1.0.1000.10000")]

?

sreejith ss nair15-Aug-04 23:59

15-Aug-04 23:59

Goahead

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CNU15-Aug-04 21:57

CNU

15-Aug-04 21:57

Did you register your assemblies (dll) in C:\WINNT\assembly folder (for WIN 2K)??
If yes, you have to again regiter the dll files in the assembly, every time you change them.

CNU

ting66815-Aug-04 23:45

15-Aug-04 23:45

I am writing private assembly.
The dll is just for the application use.

In fact, can the application run regardless the version of the dll?

CNU15-Aug-04 23:59

CNU

15-Aug-04 23:59

Yes...it is very much possible. As far as my knowledge goes, the version comes into picture only when you register the dll in assembly (correct me if I'm wrong).

It seems there could be some other problem. Why don't you put the error message here (that comes in your output window) ?? Or put a try catch block where your refer the dll's methods and print the exception...

Cheers
CNU

leppie16-Aug-04 2:28

leppie

16-Aug-04 2:28

ting668 wrote:
So, can we ignore the version of the dll so that the application can be run without the runtime error?

You can try, but something is bound to break, if you break the interface. I suggest you create some interfaces and use them rather than the implementation classes. This will ensure you or someone dont go and break it.

^{top secret xacc-ide 0.0.1}

LongRange.Shooter16-Aug-04 5:29

LongRange.Shooter

16-Aug-04 5:29

There are two ways that you can deal with the versioning issue.

The first is to manually manage your version numbers. This is done via the AssemblyInfo.cs file. When the version value is 1.0.* the * tells the compiler to increment with each build. Making it fixed: 2.5.0.0 for example, makes it a fixed version number. The problem is that a developer can make a breaking change and not reflect it since they forgot to change version number.

The second approach is to use reflection to load the assembly. Doing something similar to this: (untested code written off the top of my head)

string ObjectName = Path.Combine(dllPath, dllName);
Assembly container = Assembly.LoadFile(ObjectName);
Type object = container.GetType(objectNamespace);
object.InvokeMember(methodName, blah blah blah)

You can load the dll regardless of version. But you are now doing it all late binding which is TERRIBLY slow. I highly recommend you not consider doing this method.

This signature left intentionally blank

ting66816-Aug-04 15:53

Invoke/BeginInvoke Problem

16-Aug-04 15:53

Thanks~

I try it. However, the third statement
Type object = container.GetType(objectNamespace);

throw exception.

khchan15-Aug-04 20:56

khchan

15-Aug-04 20:56

Hi,

I have developed 2 apps, AppA and AppB.
AppA is a TCP Client
AppB is a TCP Server

When AppB receives a msg from AppA, it will update the view. If I update a TextBox, Label or ListView, it works fine. However, if I update a TreeView (add a new TreeNode), it throws an exception that asks me to use Invoke or BeginInvoke.

Why it just doesn't work on TreeView? and Why using Invoke/BeginInvoke can solve this problem?

thanks Poke tongue | ;-P

Re: Invoke/BeginInvoke Problem

Stanciu Vlad16-Aug-04 2:08

Stanciu Vlad

16-Aug-04 2:08

I think you problem comes from a mistake in your code, maybe if you show us a litle piece of the code (the "update" process you mentioned) maybe we can help you.

Wink | ;)

I hope you understand...

Re: Invoke/BeginInvoke Problem

leppie16-Aug-04 2:39

leppie

16-Aug-04 2:39

Controls should not be modified directly from another thread. Use Control.Invoke to dispatch the function call into the UI thread.

^{top secret xacc-ide 0.0.1}

Re: Invoke/BeginInvoke Problem

khchan16-Aug-04 16:59

khchan

16-Aug-04 16:59

Hi,

what if somebody is updating the view from AppB(the server) directly and at the same time, AppA(the client) is asking AppB to update.

(what i meant "update the view" may just be sth like textBox1.Text = "blah" or treeView1.Nodes.Add("blah") )

Can Control.Invoke handle this case?

thanks Roll eyes | :rolleyes:

Inherited GroupBox or Panel

Click^ok15-Aug-04 20:56

Click^ok

15-Aug-04 20:56

Hello friends

I create a windows forms user control and put a panel inside. Then I build a project and I get the usercontrol from the toolbox and put in a new form. But the panel does not works as waited in design time... I cannot put controls inside... I have tried with Groupbox and Tabcontrols, and doesn't works too.

What I can do to can add controls in design time? In runtime I know what I can use the "Controls.Add", but I wish this in design too

I thank in advance ay help

Regards

Re: Inherited GroupBox or Panel

sreejith ss nair15-Aug-04 21:44

Re: Inherited GroupBox or Panel

15-Aug-04 21:44

hi,

private void Form1_Load(object sender, System.EventArgs e)
{
//sample user control
UserControl1 sr=new UserControl1();
//adding user control to your main form
this.Controls.Add(sr);
//creating one button
Button btn=new Button();
//changing back color
btn.BackColor=Color.Red;
sr.Controls[0].Controls.Add(btn);
}

Here you have a form with user control. If you want to add controls inside the user control which contain some groupbox or panel.Then you can refer the control (group or panel ) using there index.

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Click^ok15-Aug-04 21:56

Click^ok

15-Aug-04 21:56

Thank you sreejith

But your sample code work in runtime only...

Imagine:

1) If you drag a Panel from toolbox to your form (in design), you can add other controls to this panels, simply dragging a label, button, etc, inside of this Panel.

2) But if you create a User Control with a panel inside. We will call "UserPanelControl". Now you drag this usercontrol from toolbox in the form. The Panel what is inside of our UserPanelControl is unable to receive dragged controls from VS.Net IDE (like labels, buttons) inside....

Regards

Structure and Interface

Paul Selormey15-Aug-04 19:53

Paul Selormey

15-Aug-04 19:53

Consider the following codes

using System;

namespace ConsoleApplication1
{
    interface IPointD
    {  
        double X {get; set;}
        double Y {get; set;}
    }

    struct PointD : IPointD
    {
        private double x;
        private double y;
        public PointD(double x, double y)
        { this.x = x; this.y = y;}

        public double X 
        { 
            get { return x; } 
            set { x= value; }
        }

        public double Y 
        {
            get { return y; }
            set { y = value; }
        }
    }

	class Class1
	{
        static void Method(IPointD point)
        {
            if (point != null)
            {
                point.X = 10;
                point.Y = 10;
            }
        }

		[STAThread]
		static void Main(string[] args)
		{
            PointD point = new PointD(1, 1);
            IPointD dPoint = (IPointD)point;
            Method(dPoint);

            Console.WriteLine("X = {0}, Y = {1}", point.X, point.Y);
            Console.WriteLine("X = {0}, Y = {1}", dPoint .X, dPoint.Y);
		}
	}
}

Why is the dPoint modified, but "point" is not in the call to Method?

Does the cast

IPointD dPoint = (IPointD)point;

creates a copy of the "point"?

Best regards,
Paul.

Jesus Christ is LOVE! Please tell somebody.

S Sansanwal15-Aug-04 21:03

S Sansanwal

15-Aug-04 21:03

Because point is an object of structure and dPoint is an object of interface
The difference is Structure are by value and class/interface object are by reference.

In C#, classes and structs are semantically different. A struct is a value type, while a class is a reference type.

Sanjay Sansanwal
www.sansanwal.com

Paul Selormey15-Aug-04 21:32

Paul Selormey

15-Aug-04 21:32

Thanks for the response.
I understand the basics of structs and classes in C#, so this does not really answer my question.

Best regards,
Paul.

Jesus Christ is LOVE! Please tell somebody.

Nick Parker16-Aug-04 3:29

Nick Parker

16-Aug-04 3:29

Paul Selormey wrote:
Why is the dPoint modified, but "point" is not in the call to Method?

Interfaces provide a binding contact, thus the object inheririting from the interface is required to implement whatever the interface defines. This is what allows your cast above to IPointD to succeed. dPoint is simply making its calls through your point object. Does this make sense?

- Nick Parker
My Blog | My Articles