Re: Closing all mdichildren forms - C# Discussion Boards

Heath Stewart14-Jun-04 8:52

14-Jun-04 8:52

You can't change a collection while enumerating it. Calling Close ultimately will change the collection. Instead, use:

for (int i=0; i<MdiChildren; i++)
{
  Form f = (Form)MdiChildren[i];
  f.Close();
}

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Dylan van Heerden14-Jun-04 9:23

Dylan van Heerden

14-Jun-04 9:23

Right now comes the this. I've got 3 mdichildren forms and when I click the button to close all the forms, only 2 closes and 1 stays open until I click the button again. Is it because I did the following like u showed except I added .Length.

for (int i = 0; i < MdiChildren.Length; i++)
{
Form f = (Form)MdiChildren[i];
f.Close();
}

Sweet

Heath Stewart14-Jun-04 9:25

14-Jun-04 9:25

Sorry - I made a mistake. You should either run through the array backward or make a copy of the array (and forgetting .Length was a typo - it's only sample code):

for (int i=MdiChildren.Length; i >= 0; i--)
{
  Form f = MdiChildren[i]; // Cast really not necessary
  f.Close();
}

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Dylan van Heerden14-Jun-04 9:39

Dylan van Heerden

14-Jun-04 9:39

Thanks it works. All I had to do is add the - 1

for (int i = MdiChildren.Length - 1; i >= 0; i--)
{
Form f = MdiChildren[i];
f.Close();
}
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My brain is 2 small for all the knowledge that I need.

Directx Writepixel in .NET

LongRange.Shooter14-Jun-04 10:12

LongRange.Shooter

14-Jun-04 10:12

You were real close, here is my CloseAllChildren process for my MDIParent:

private void CloseAllChildren()
{
    System.Windows.Forms.Form[] myChildren = this.MdiChildren;
    foreach (Form child in myChildren)
    {
        child.Close();
    }
    return;
}

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eldrago14-Jun-04 6:49

eldrago

14-Jun-04 6:49

Hi everyone.

Could anyone give me a few pointers on how to write a writepixel method with directx for .NET please?

Thanks.

Re: Directx Writepixel in .NET

Jeremy Kimball14-Jun-04 9:02

Jeremy Kimball

14-Jun-04 9:02

Without going into too much detail, it's not quite that easy. There are two ways to do what you're talking about. One is blitting a one pixel blob to the location specified. The other involves locking the surface buffer, and then using the desired coordinates (x,y) and the stride of the surface (# of bytes/scan line) to determine the offset needed to set.

Kinda like this: (not compilable code)

WritePixel(Surface surf, int x, int y, int col) {
    int[] surfaceContents = surf.Lock(....);
    int offset = (y * surf.width * surf.SurfaceDescription.Stride) + x;
    surfaceContents[offset] = col;
    surf.Unlock();
}

You're better off searching thru Google about the actual formula involving X, Y, and stride. I can't remember exactly where the stride fits in at this second.

Good luck Smile | :)

Jeremy Kimball

I have traveled the gutters, lo these many days, with no signs of life. Well met.
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Re: Directx Writepixel in .NET

eldrago14-Jun-04 20:00

eldrago

14-Jun-04 20:00

Hello again.

This is how I now try to do it

public void WritePixel(int color,int x, int y)
{
Array surfaceContents = _surface.Lock(LockFlags.SurfaceMemoryPointer);

int offset = ( x ) + ( _surface.SurfaceDescription.Pitch * y);

surfaceContents.SetValue(color,offset);

_surface.Unlock(null);
}

However I get an error that says lock doesn't return Array, although that it is what is stated in the ms documentation. Is this a bug or am I just doing things the wrong way?

Thanks.

Re: Directx Writepixel in .NET

Jeremy Kimball15-Jun-04 3:00

Jeremy Kimball

15-Jun-04 3:00

It's of *type* Array, but think of it more as an Array of *something*.

As in:

Array == int[], or byte[,], etc.

Actually, if memory serves, Surface.Lock actually returns a 2D byte array, but my memory sucks, so check through Google to make sure.

If I'm right:

byte[,] surfaceContents = Surface.Lock(LockFlags.SurfaceMemoryPointer);

Good luck

Jeremy Kimball

I have traveled the gutters, lo these many days, with no signs of life. Well met.
-brianwelsch

Synchronized Databinding

WillemM14-Jun-04 6:43

WillemM

14-Jun-04 6:43

I have a Custom Collection based on IList, so I can bind it to a datagrid. But if I change an item in the collection the information on the grid doesn't change.

How can I get this to work, like the dataset databinding works? If I update an item in a datatable in a dataset the grid gets updated instantly.

"Every rule in a world of bits and bytes can be bend or eventually be broken"

Re: Synchronized Databinding

WillemM14-Jun-04 7:51

WillemM

14-Jun-04 7:51

I found a solution. My databinding enabled list needed some improvements Smile | :)

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnadvnet/html/vbnet02252003.asp[^]

This page explains how you can make a synchronized databound collection.

"Every rule in a world of bits and bytes can be bend or eventually be broken"

DataGrid CheckBoxes

exhaulted14-Jun-04 6:23

14-Jun-04 6:23

Hi all,

I have seen lots of articles on the subject of datagrid controls and check boxes. I am currently designing a goods movement system for the company i work for and i have most of it finished. However, on the last page i want to display a datagrid control with data that has been entered on previous pages, that bit i have done including formatting the datagrid (which took some figuring out but i got there in the end).

The user will have to go through each entry every week and tick them off one by one. I have added a DataGridBoolColumn object to the TableStyle.GridColumnStyles collection and the check box displays fine. However i have 2 problems.

1. The default value for the check boxes is true, i need it to be false and setting the value to false when setting up the column in code doesn't work. Although by answering the next question this might be solved.

2. Whenever i tick/untick the box then move the focus away from the cell in the grid the checkbox returns to a checked state.

any help that you can give me would be appreciated.

Cheers

KP

Heath Stewart14-Jun-04 6:28

14-Jun-04 6:28

You don't have it bound to a data column correctly. The default value only applies when the data the column is bound to doesn't already have a value. Likewise, if it's not bound correctly it always appears checked.

Read the documentation for the DataGrid.DataSource and DataGrid.DataMember properties about binding data - any IList or IListSource implementation like a DataSet or DataTable - to the DataGrid, as well as the DataGrid.TableStyles about how to apply table styles to a particular data source.

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exhaulted14-Jun-04 22:09

14-Jun-04 22:09

Heath,
thanks for your advice but i have already bound the DataGrid to a DataSet

dataSAR.DataSource = gmb.gmbSet; //DataSet in the gmb object<br />
dataSAR.DataMember = "SAR"; //Table Name

Then i set up a DataGridTableStyle, mapped it to the table.

DataGridTableStyle sarStyle = new DataGridTableStyle();<br />
sarStyle.MappingName = "SAR";

Next i created a DataGridBoolColumn object and mapped it to the corresponding column in the table

DataGridBoolColumn checkColumn = new DataGridBoolColumn();<br />
checkColumn.MappingName = "Checked";

Finally i added the column to the TableStyle and added the TableStyle to the DataGrid.TableStyles collection.

sarStyle.GridColumnStyles.Add(checkColumn);<br />
dataSAR.TableStyles.Add(sarStyle);

I think that this is the correct way of going about this but i am having the problems mentioned in the above post so any advice about what i am doing wrong would be appreciated.

Cheers

KP

Heath Stewart15-Jun-04 2:32

15-Jun-04 2:32

Make sure the TrueValue and FalseValue properties are set to whatever you use for true and false values. These values are case-sensitive.

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exhaulted15-Jun-04 5:40

15-Jun-04 5:40

How would that affect me checking / unchecking the check box at runtime? When i uncheck the box at runtime, as soon as the focus goes to another part of the form the box is checked again.

KP

Heath Stewart15-Jun-04 5:53

15-Jun-04 5:53

It's called data-binding. Controls are bound to data, which is updated when the control is changed and vice versa. If the true/false values are not the same for both, the value can't be bound.

Read the class documentation for the DataGridBoolColumn in the .NET Framework SDK for more information.

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exhaulted15-Jun-04 6:17

15-Jun-04 6:17

Heath,

I have set the default true/false values for the DataGridBoolColumn to lower case true and false so that they match with the Value applied when a check box is checked / unchecked and it appears to work.

Thanks for all your help, i really don't think i would have figured this one out by myself.

KP

DataGrid CheckBoxes

exhaulted14-Jun-04 6:23