Re: Strings and Interop - C# Discussion Boards

26-Jan-06 10:58

I think refresh() changes the date, all painting should be in paint / invalidate()

Invalidate() is what tells the system to re-draw the client area - call that whenever focus enters the form or leaves the combobox

system tray

mehrdadc4826-Jan-06 9:36

mehrdadc48

26-Jan-06 9:36

Hi.
How can send my programm to system tray.
I write a clock alarm program and want when running go to system tray.

Best wishes

Re: system tray

André Ziegler26-Jan-06 10:02

André Ziegler

26-Jan-06 10:02

You can use the NotifyIcon[^]-Component.

'A programmer is just a tool which converts caffeine into code'

Re: system tray

Ravi Bhavnani26-Jan-06 10:20

Ravi Bhavnani

26-Jan-06 10:20

See this[^] link.

/ravi

My new year's resolution: 2048 x 1536
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Strings and Interop

Beringer26-Jan-06 9:27

26-Jan-06 9:27

Can someone please tell me how to create the appropriate buffer to hold characters in a LPCTSTR buffer in C#. I have tried using Strings but the results are chaotic to say the least.

For instance, SendMessage, often will use a LPCTSTR in the LPARAM to return a collection of characters. How do I create the appropriate array in C#.

Eric

Beringer26-Jan-06 9:50

26-Jan-06 9:50

I'm sorry to be more clear, How do I get a string safely into an IntPtr since I have defined my SendMessage with LPARAM as an IntPtr?
Thanks,
Eric

Andy Moore26-Jan-06 11:17

Andy Moore

26-Jan-06 11:17

Try System.Runtime.InteropServices.Marshal.StringToHGlobalAnsi(Auto/Uni). This will do the trick.

Andy

Human beings were not meant to sit in little cubicles staring at computer screens all day, filling out useless forms and listening to eight different bosses drone on about about mission statements. -- Peter Gibbons

Beringer26-Jan-06 17:52

26-Jan-06 17:52

Thanks Andy, this seems to work!
Eric

James Gupta26-Jan-06 10:59

26-Jan-06 10:59

Try casting it to a C# string from a lpcstr

DigitalKing26-Jan-06 14:36

DigitalKing

26-Jan-06 14:36

Use StringBuilder from the System.Text namespace.

[DllImport("kernel32.dll")]
    static extern bool GetVolumeNameForVolumeMountPoint(string lpszVolumeMountPoint, [Out] StringBuilder lpszVolumeName, uint cchBufferLength);

public static string GetVolumeName(string MountPoint)
{
    StringBuilder sb = new StringBuilder();
    GetVolumeNameForVolumeMountPoint(MountPoint, sb, 100);
    return sb.ToString();
}

Beringer26-Jan-06 15:27

Help with Code conversion

26-Jan-06 15:27

I tried a StringBuilder but I got empty strings back. I think it has to do with the LPARAM parameter needing to be LPCSTR type pointer and StringBuilder is in appropriate.

What I am trying to do is use the SendMessage API to get the textline in an edit control with EM_GETLINE. The LPARAM parameter in this case is an LPCSTR pointer to a buffer of characters and I just don't know how to allocate the memory for this to happen correctly.

Thanks,
Eric

TMF32026-Jan-06 7:11

26-Jan-06 7:11

I recently recieved a snipit of code from a friend that contained a character I was unfamiliar with and in fact that my conversion tool was unfamiliar with as well.

The code contained a charcter of pipes (||) used to represent an "OR" argument. The original code was written in VB.

Can someone tell me the equivilent of || for the "OR" argument in C#?

Here is the line of code:

<br />
//N.B. I am using VB.NET most of the time, so my C# syntax may not be 100% correct <br />
sub void Customers1_ItemDataBound(Object sender, RepeaterItemEvenArgs e) <br />
{ <br />
<br />
//NOTICE: you might need to adjust this line of code accordingly if you include the nested Repeaters in the <SeperatorTemplate> <br />
if (e.Item.ItemType = ListItemType.Item) || (e.Item.ItemType = ListItemType.AlternatingItem) <br />
<br />
{ <br />
//This is to look for the Customers2 repeater that is nested inside the Customers1 repeater <br />
Repeater oRpt = (Repeater) e.Item.FindControl("Customers2") <br />
DataRowView oDrv = e.Item.DataItem <br />
<br />
'Bind item repeater <br />
//This line is to retrieve only the records in the CTPT table that have the same ItemID as the HSCTI record in the current row <br />
oRpt.DataSource = oDrv.CreateChildView("ItemID") <br />
oRpt.DataBind <br />
end if <br />
} <br />
<br />
//Similarly, to show all the related comments on the Customers2 repeater, you include code in the Customers2_ItemDataBound() event <br />
sub void Customers2_ItemDataBound(Object sender, RepeaterItemEvenArgs e) <br />
{ <br />
<br />
//NOTICE: and this line of code as well <br />
if (e.Item.ItemType = ListItemType.Item) || (e.Item.ItemType = ListItemType.AlternatingItem) <br />
<br />
<br />
{ <br />
//This is to look for the Customers3 repeater that is nested inside the Customers2 repeater <br />
Repeater oRpt = (Repeater) e.Item.FindControl("Customers3") <br />
DataRowView oDrv = e.Item.DataItem <br />
<br />
'Bind item repeater <br />
//This line is to retrieve only the records in the CTPT table that have the same ItemID as the HSCTI record in the current row <br />
oRpt.DataSource = oDrv.CreateChildView("ct_number") <br />
oRpt.DataBind <br />
end if <br />
} <br />

Thank you for your help.

Sincerely,

Tim

Guffa26-Jan-06 7:24

Guffa

26-Jan-06 7:24

The equivalent for || in C# is ||.

The problem you have is that the syntax of the if statement is wrong. The syntax should look like this:

if (expression) { ... }

What you have is:

if expression { ... }

Put a parenthesis around the expression, and you will get further.

---
b { font-weight: normal; }

TMF32026-Jan-06 7:46

26-Jan-06 7:46

Guffa,

Thanks so much for the pointer. I can't believe I didn't see that. What I did was to immediately put the code into the converter to get a first pass at it in C# when it failed on the pipes[||].

Thank you again.

Tim

Dan Neely26-Jan-06 8:29

Dan Neely

26-Jan-06 8:29

TMF320 wrote:

Thanks so much for the pointer. I can't believe I didn't see that.

Don't feel bad, I did the same thing repeatedly while porting an algorithm from vba to c#.

Dave Kreskowiak26-Jan-06 8:39

Dave Kreskowiak

26-Jan-06 8:39

This should be RepeaterItemEventArgs and is found in the System.Web.UI.WebControls namespace. This is in the file System.Web.dll.

If you're making a ASP.NET application, this reference is set for you automatically when you create the new web app.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

-- modified at 14:39 Thursday 26th January, 2006

TMF32026-Jan-06 8:01

26-Jan-06 8:01

Guffa,

In continuing with my conversion, could you tell me what the assembly reference for RepeaterItemEvenArgs is?

I get an error on this line:
public void Customers1_ItemDataBound(Object sender, RepeaterItemEvenArgs e)

Thanks again.

Tim

TMF32026-Jan-06 8:34

26-Jan-06 8:34

Ignore this. Typo!

RepeaterItemEventArgs not RepeaterItemEvenArgs.

Click... Shoot....

James Gupta26-Jan-06 7:40

26-Jan-06 7:40

|| is a logical OR in C#

TMF32026-Jan-06 9:46

26-Jan-06 9:46

James,

Thank you also for your reply!

I wanted to know if you could help me through this error? THe following error is generating the following error:
'System.Web.UI.WebControls.ListItemType' is a 'type' but is used like a 'variable'

The code in question:

<br />
<small><br />
public void Customers1_ItemDataBound(Object sender, RepeaterItemEventArgs e) <br />
    {<br />
        if((e.Item.ItemType = ListItemType)||(e.Item.ItemType = ListItemType.AlternatingItem))<br />
        {<br />
            //This is to look for the Customer2.Repeater that is nested inside the Customer1.Repeater.<br />
            Repeater oRPT = (Repeater)e.Item.FindControl("Customer2");<br />
            DataRowView oDrv = e.Item.DataItem;<br />
            //This line is to retrieve only the records in the CTPT table that have the same ItemID as the HSCTI record in the current row.<br />
            oRPT.DataSource = oDrv.CreateChildView("ItemID");<br />
            oRPT.DataBind();<br />
        }<br />
    }<br />
<br />
    //Show all related Comments on the Customers2 Repeater.<br />
    public void Customers2_ItemDataBound(Object sender, RepeaterItemEventArgs e)<br />
    {<br />
        if ((e.Item.ItemType = ListItemType) || (e.Item.ItemType = ListItemType.AlternatingItem))<br />
        {<br />
            //This is to look for the Customer2.Repeater that is nested inside the Customer2.Repeater.<br />
            Repeater oRPT = (Repeater)e.Item.FindControl("Customer3");<br />
            DataRowView oDrv = e.Item.DataItem;<br />
            //This line is to retrieve only the records in the CTPT table that have the same ItemID as the HSCTI record in the current row.<br />
            oRPT.DataSource = oDrv.CreateChildView("ct_number");<br />
            oRPT.DataBind();<br />
        }<br />
    }<br />
</small><br />

Thank you for your help.

Sincerely,
Tim

James Gupta26-Jan-06 10:23

26-Jan-06 10:23

The error says that you are using a type as an instance (ie trying to assign values to a CLASS not an INSTANCE of it). Basically, just change the "=" in the if loops to a "=="

This may have been a simple typing mistake (happens to me all the time lol) but just in case:

"=" is the assignment operator, it assigns the value at the right hand side to that on the left.

"==" is a logical operator which tests if the two values are equal (ie if(MyAge == FilmAge))

Hope that helps

TMF32026-Jan-06 10:29

26-Jan-06 10:29

James,

To be honest it was no typing error (just inexperience). I appreciate your additional explaination. It helps me to learn.

UNfortunately though, I am still getting the error. Could there be another reason for this occurance?

Thank you again for your time.

Tim

TMF32026-Jan-06 11:24

26-Jan-06 11:24

James,

What I was able to discover was that if I followed intellisense and used Item instead of LinkItem I was able to get by the error:

if ((e.Item.ItemType == ListItemType.Item) || (e.Item.ItemType == ListItemType.AlternatingItem))

This however, produced another error which I haven't been able to get by:

Cannot implicitly convert type 'object' to 'System.Data.DataRowView'. An explicit conversion exists (are you missing a cast?)

This is referencing line:
DataRowView oDrv = e.Item.DataItem;

From the following code:

<br />
<small><br />
public void Customers1_ItemDataBound(Object sender, RepeaterItemEventArgs e) <br />
    {<br />
        if ((e.Item.ItemType == ListItemType.Item) || (e.Item.ItemType == ListItemType.AlternatingItem)) <br />
        {<br />
            //This is to look for the Customer2.Repeater that is nested inside the Customer1.Repeater.<br />
            Repeater oRPT = (Repeater)e.Item.FindControl("Customer2");<br />
            DataRowView oDrv = e.Item.DataItem;<br />
            //This line is to retrieve only the records in the CTPT table that have the same ItemID as the HSCTI record in the current row.<br />
            oRPT.DataSource = oDrv.CreateChildView("ItemID");<br />
            oRPT.DataBind();<br />
        }<br />
    }<br />
<br />
    //Show all related Comments on the Customers2 Repeater.<br />
    public void Customers2_ItemDataBound(Object sender, RepeaterItemEventArgs e)<br />
    {<br />
        if ((e.Item.ItemType == ListItemType.Item) || (e.Item.ItemType == ListItemType.AlternatingItem)) <br />
        {<br />
            //This is to look for the Customer2.Repeater that is nested inside the Customer2.Repeater.<br />
            Repeater oRPT = (Repeater)e.Item.FindControl("Customer3");<br />
            DataRowView oDrv = e.Item.DataItem;<br />
            //This line is to retrieve only the records in the CTPT table that have the same ItemID as the HSCTI record in the current row.<br />
            oRPT.DataSource = oDrv.CreateChildView("ct_number");<br />
            oRPT.DataBind();<br />
        }<br />
    }<br />
</small><br />

Do you have any thoughts on this?

Thank you for your help. Trying to meet a deadline by morning. Will be here all night if necessary.

Regards,

Tim