Re: GetCursorInfo in C#? - C# Discussion Boards

4-Aug-03 4:38

Does anyone know how i can use the GetCursorInfo API in C#? I'd like to know the dllimport and an example code.

Click here to view the GetCursorInfo API.

Heath Stewart4-Aug-03 6:00

4-Aug-03 6:00

You have to recreate the sturct and ref that in your P/Invoked statement:

public struct CursorInfo
{
    public int size;  // Or uint, but probably not necessary and
    public int flags; // isn't CLS compliant.
    IntPtr cursor;
    System.Drawing.Point point; // Should already marshal correctly.
}
[DllImport("user32.dll", CharSet=CharSet.Auto)]
public static extern bool GetCursorInfo(ref CursorInfo info);

CyberKewl4-Aug-03 13:37

4-Aug-03 13:37

Thanks for the quick reply but i'd like to know how to use it too. I'd like to know how to get the cursor image (or icon) using GetCursorInfo.

Heath Stewart5-Aug-03 5:25

5-Aug-03 5:25

It's all in the documentation on MSDN. I suggest you read it. There's examples, too. Always consult the docs for questions like this, when asking "what is X" or "how does Y" work, otherwise you're just grabbing at straws and guessing, which doesn't build any skills. I don't mean to sound rude, but researching is half the development battle, and these questions are exactly what the Windows API functions, .NET class library, and other documentation is for. Besides, it'd be a waste of time to essentially copy and paste the topic you want. Just type GetCursorInfo in the index and you've got what you want. As far as managed code goes, however, read on...

If all you're trying to do is read-in a cursor image, then you need to look at the Cursor class. It's better to use managed code than to start needlessly P/Invoking stuff from the Win32 API. It has everything you apparently need to read-in a cursor and display it (either as the mouse cursor or a bitmap (with some fiddling) such as a preview pic).

CyberKewl5-Aug-03 13:27

5-Aug-03 13:27

I'm aware of that. The thing is, i don't understand how to use GetCursorInfo. I just need some help in getting the cursor image which is vital for my program, that's all. Anyway, i'll try reading again.

Heath Stewart5-Aug-03 17:03

5-Aug-03 17:03

If all you want is the cursor image to draw on a surface or something, the Cursor class documentation provides all the information you need - no P/Invoke is necessary. As I said, use managed code whenever possible.

See Cursor.Current and Cursor.Draw():

// Get the current cursor.
Cursor c = Cursor.Current;
Graphics g = this.myControl.CreateGraphics();
c.Draw(g, this.myControl.Bounds);
g.Dispose();

CyberKewl6-Aug-03 0:47

6-Aug-03 0:47

No, i just need to know the name of the cursor whether it is a normal cursor showing or wait cursor showing - system-wide (not just within the current form). From my understanding, if you use Cursor.Current, you can only get the name of the cursor that is showing within the form. If the cursor moves outside of the form, the name of the cursor will not be changed.

Heath Stewart6-Aug-03 4:28

6-Aug-03 4:28

As I stated before, recreate the structure and P/Invoke the interface:

[StructLayout(LayoutKind.Sequential)]
public struct CursorInfo
{
  public int Size;
  public int Flags;
  public IntPtr Handle;
  public Point Position;
}
public class NativeMethods
{
  [DllImport("user32.dll")]
  public static extern bool GetCursorInfo(out CursorInfo info);
}

Based on this code and the docs for GetCursorInfo, calling it should be no problem:

CursorInfo info = new CursorInfo();
info.Size = Marshal.SizeOf(info.GetType());
if (NativeMethods.GetCursorInfo(out info))
{
  // info.Handle contains the global cursor handle.
  Cursor c = new Cursor(info.Handle);
}

I've tested this and it does work fine.

CyberKewl6-Aug-03 14:16

Datagrids - Selecting Rows

6-Aug-03 14:16

Thanks a lot. That did the trick.

MrEyes4-Aug-03 3:02

MrEyes

4-Aug-03 3:02

Let assume I have a datagrid that contains the following data

ID  VAL1  VAL2  VAL3
1   abc   def   ghi
2   jkl   mno   pqr
3   stu   vwx   yz1
4   234   567   890

On the same form I also have a list box with the following values :

2
4

Using the 'SelectIndexChanged" event I want to highlight the relevant ID in the data grid. So lets say I click on '4' the following line in the datagrid would be selected :

4   234   567   890

Kannan Kalyanaraman4-Aug-03 5:19

Kannan Kalyanaraman

4-Aug-03 5:19

I think you can use the below function of datagrid

DataGrid.Select(rowIndex)

I'm not sure about how you'd get the rowindex of that particular id.

- Kannan

MrEyes4-Aug-03 5:22

MrEyes

4-Aug-03 5:22

Thats about as far as I got with it.

I just couldnt find a way to get the rowIndex for the selected value in the listbox

Heath Stewart4-Aug-03 6:05

4-Aug-03 6:05

There's many ways. If your DataGrid is not sorted and hasn't been sorted, you can use a myriad of method to get the index of the row in the data source, then use that in DataGrid.Select(). If you knew the index of the column for the key, you could use the DataGrid.Item and loop through rows (using for instead of foreach so you can get the index from, say, i's current value when you find what you're looking for). It's all in the documentation. Just spend a little time researching what's available before jumping into it. You can use members on DataGrid, the DataSet, a DataRow or DataRowView, or even use a strongly-typed DataSet which provides you with additional options.

MrEyes5-Aug-03 0:42

MrEyes

5-Aug-03 0:42

Well after some playing I came up with this piece of rather convoluted code, but it does what I need. Here it is just incase anybody else is looking for something similar in the future :

//item (string) - value to be selected
CurrencyManager cm = (CurrencyManager)dgData.BindingContext[dgData.DataSource];
		
for (int i = 0; i < cm.Count; i++)
{
  DataRowView drv = (DataRowView)cm.List[i];
			
  if (item == drv.Row["CDBNO"].ToString())
  {
    dgData.CurrentRowIndex = i;
    dgData.Select(i);
  }
}

Heath Stewart5-Aug-03 5:34