Help with Code conversion - C# Discussion Boards

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

Re: Strings and Interop

Beringer26-Jan-06 9:50

Beringer

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

Re: Strings and Interop

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

Re: Strings and Interop

Beringer26-Jan-06 17:52

Beringer

26-Jan-06 17:52

Thanks Andy, this seems to work!
Eric

Re: Strings and Interop

James Gupta26-Jan-06 10:59

James Gupta

26-Jan-06 10:59

Try casting it to a C# string from a lpcstr

Re: Strings and Interop

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();
}

Re: Strings and Interop

Beringer26-Jan-06 15:27

Beringer

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

Help with Code conversion

TMF32026-Jan-06 7:11

TMF320

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