Develop Reference

Adding panels programatically based on .top is being based on the scroll of its parent

I am looking for some assistance in fixing an issue. At the moment I have developed some code that adds a user control to a panel. It adds multiple user controls to the panel and does this based on the .top feature. However, once the panel that I am adding the user controls to is scrolled down the user controls seem to be placed strangely.
I have already tried to adjust the .top value but I am not sure how to do it in relation to the scroll of the panel.
int i = 0;
foreach(memberInformation mi in pnlMembers.Controls.OfType<memberInformation>())
{
try
{
if (UserInformation.isPartyLeader)
{
mi.canUserEdit = "true";
}
else
{
mi.canUserEdit = "false";
}
mi.playerName = downloadInfo.Split(':')[i].Split(',')[0];
mi.playerRole = downloadInfo.Split(':')[i].Split(',')[1];
}
catch
{
pnlMembers.Controls.Remove(mi);
}
i++;
}
VIDEO to show what is happening: https://gyazo.com/985566afb7e4bab464dd06da191a0710
https://gyazo.com/4b0514cbdb310ea8abc46a397458130c

The correct way in order to position panels inside another panel is to use flowlayoutpanel.
Thanks

Winform DataGRidView Scroll Bar not showing until needed [duplicate]

I have a winform in vs2008 that contains a DataGridView. The datagrid contains a list with several columns. These are fixed width, exept one that I have set up to take whatever space is left and fill the width of the view. The winform is resizeable in all directions.
The issue I am trying to solve is that when I increase the vertical size of the window the scrollbar disappears and the columns snap to the right to fill the extra space. What I would like to happen is that the vertical scrollBar never disappears. Setting ScrollBars to vertical in the properties of the DataGridView does not do this.
Is this at all possible to achieve? And, if so, how do I get the vertical scrollbar to always be visible?

Try subclassing the DataGridView and handling the VerticalScrollBar's VisibleChanged event. You should be able to set the Visible property to True in there, overriding the default behaviour.
Something like this, I think...
public class SubclassedDataGridView : DataGridView
{
public SubclassedDataGridView (): base()
{
VerticalScrollBar.VisibleChanged += new EventHandler(VerticalScrollBar_VisibleChanged);
}
void VerticalScrollBar_VisibleChanged(object sender, EventArgs e)
{
VerticalScrollBar.Visible = true;
}
}

In my case, (re)sorting the grid helped. Try sth like this:
if (gridName.SortedColumn == null)
gridName.Sort(gridNameColumns[columnName],ListSortDirection.Ascending);
else
{
ListSortDirection dir;
if (gridName.SortOrder == SortOrder.Descending)
dir = ListSortDirection.Descending;
else dir = ListSortDirection.Ascending;
gridName.Sort(gridName.SortedColumn, dir);
}

One of the possibility is to trigger the event of when the scrollbar is disapearing so you can prevent the event and stop it.

ObjectListView editing doesn't work

I'm trying to create a simple listbox with ObjectListView (WinForm, C#). The goal is to have a single value (a double) and a check box.
I want to be able to edit the double value by Single Click, so here are the relevant lines of code from my MyWindow.Designer.cs file (i've left out the default values for efficiency):
this.olvDepths = new BrightIdeasSoftware.ObjectListView();
this.olvColumn1 = ((BrightIdeasSoftware.OLVColumn)(new BrightIdeasSoftware.OLVColumn()));
...
this.olvDepths.CellEditActivation = BrightIdeasSoftware.ObjectListView.CellEditActivateMode.SingleClick;
this.olvDepths.CheckBoxes = true;
this.olvDepths.CheckedAspectName = "IsDefault";
this.olvDepths.FullRowSelect = true;
//
// olvColumn1
//
this.olvColumn1.AspectName = "Depth";
this.olvColumn1.Text = "";
this.olvColumn1.IsEditable = true;
I then create a list of my class (ShieldingEntry) and use the olvDepths.SetObjects() with the list. My ShieldingEntry class looks like this:
public class ShieldingEntry
{
public double Depth { get; set; }
public bool IsDefault { get; set; }
}
However, when I click the field, it doesn't go into edit mode. I've also tried the DoubleClick, SingleClickAlways, and F2Only modes and they don't work either.
The Checkbox works fine.
************** I have additional information *********************
I've pulled and build the ObjectListView source, so I could step through it.
I put a breakpoint in the OLV StartCellEdit method and it gets called and appears to setup and select the control appropriately. It just never appears...
As I noted in the comments on the answer below, I've got this control on a tabbed dialog, and if I switch to another tab, then back, the control works fine.
What am I missing?

I've used ObjectListView before, and here is what I had to do:
Handle the CellEditStarting event. This event is raised when the cell goes into edit mode. Since OLV doesn't really have built-in editors, you have to make your own. Then handle the CellEditFinishing event to validate the data before putting it back into your model.
So first, handling the CellEditStarting event:
private void objlv_CellEditStarting(object sender, CellEditEventArgs e)
{
//e.Column.AspectName gives the model column name of the editing column
if (e.Column.AspectName == "DoubleValue")
{
NumericUpDown nud = new NumericUpDown();
nud.MinValue = 0.0;
nud.MaxValue = 1000.0;
nud.Value = (double)e.Value;
e.Control = nud;
}
}
This creates your editing control. If you want to make sure the size is right, you can set the size of the control (in this case a NumericUpDown) to the cell bounds using e.CellBounds from the event object.
This will show the editor when you click in the cell. Then you can handle the editor finished event to validate the data:
private void objlv_CellEditFinishing(object sender, CellEditEventArgs e)
{
if (e.Column.AspectName == "DoubleValue")
{
//Here you can verify data, if the data is wrong, call
if ((double)e.NewValue > 10000.0)
e.Cancel = true;
}
}
I don't think handling it is required, but its good practice to validate data from the user.
The editing control in the CellEditStarting event can be any control, even a user defined one. I've used a lot of user defined controls (like textboxes with browse buttons) in the cell editor.
[Edit]
I uploaded an example here dropbox link that seems to work. Might not be in the exact view as needed, but seems to do the job.

For anyone else with this problem. I had it specifically when trying to edit a 'null' value in a decimal? on the OLV on a tab page. Solution for me was to set UseCustomSelectionColors to 'False'. I didn't look elsewhere to see if it was reported as a bug. Seems like a bug.

User text input handling using TextBox

I have this control:
I'm trying to create a kind of validation, that whenever the user enters text to the TextBox, the "Add" button will be Enabled, and when the text is "" (null), the "Add" button is disabled.
I dont want to use validators.
here's the code:
protected void addNewCategoryTB_TextChanged(object sender, EventArgs e)
{
if (addNewCategoryTB.Text != "")
addNewCategoryBtn.Enabled = true;
else
addNewCategoryBtn.Enabled = false;
}
The problam is, that when the user enter's text, the "Add" button doesn't changes from disabled to enabled (and vice versa)...
any ideas?

Is it Web Forms? In Web Forms the TextChanged event of the TextBox won't fire by default.
In order to fire the event, you have to set the AutoPostBack property of the TextBox to true.
BUT, this would perform a HTTP post, what is kink of ugly, or you can wrap that in an UpdatePanel
A more elegant option, is to do that using jQuery, to do that in jQuery, you'll need some code like:
$(document).ready(function() {
$("#<%= yourTextBox.ClientID %>").change(function() {
var yourButton = $("#<%= yourButton.ClientID %>")
yourButton.attr('disabled','disabled');
yourButton.keyup(function() {
if($(this).val() != '') {
yourButton.removeAttr('disabled');
}
});
});
});

You'll need to accomplish this with Javascript, since ASP.NET is incapable of performing such client-side modifications. Think about it ... every time you pressed a letter inside the text box, it would have to postback and refresh the page in order to determine if the text box was empty or not. This is one way that ASP.NET differs from Winforms/WPF.

TextChanged events will make postback on server every time. You don't need to increase those request for such task.
You can use jquery to achieve this
var myButton = $("#btnSubmit");
var myInput=$("#name");
myButton.prop("disabled", "disabled");
myInput.change(function () {
if(myInput.val().length > 0) {
myButton.prop("disabled", "");
} else {
myButton.prop("disabled", "disabled");
}
});
JS Fiddle Demo
You just need to take care of elements Id when you are using Server Controls. For that Either you can use ClientID or set property ClientIdMode="Static"

How do I get a control which looks like a TabControl with no tabs?

We have a form which displays media items in tab pages of a tab control, and I'm implementing a feature which allows users to 'pop out' the tab pages into their own forms.
However, when I add the media player to a form rather than a TabPage, the background switches from the gradient fill of a tab page to the plain SystemColors.Control background of the parent form. I need to add the the media player to a control which has the same background as a TabControl, but which doesn't display a tab at the top. I tried adding the media player to the TabControl's control collection, but that just throws an exception.
How do I get a control which looks like a TabControl with no tabs? Should I keep trying to add the media player to a TabControl, or should I try to write a Panel with a custom-drawn background? If the latter, how do I make sure that works with all possible themes?

The questions seems to be about the UseVisbleBackgroundStyle. AFAIK only buttons and TabPages have this property.
The following is a very dirty hack, just to get you started:
1) derive a customControl from Panel and add "using System.Windows.Forms.VisualStyles;"
2) Add the following code
//warning: incomplete, add error checking etc
private readonly VisualStyleElement element = VisualStyleElement.Tab.Body.Normal;
public bool UseVisbleBackgroundStyle { get; set; }
protected override void OnPaint(PaintEventArgs pe)
{
if (UseVisbleBackgroundStyle)
{
var x = new VisualStyleRenderer(element);
x.DrawBackground(pe.Graphics, this.ClientRectangle);
}
else
{
base.OnPaint(pe);
}
}

Thanks to Henk - I eventually went with:
protected override void OnPaintBackground(PaintEventArgs e)
{
if (TabRenderer.IsSupported && Application.RenderWithVisualStyles)
{
TabRenderer.DrawTabPage(pe.Graphics, this.ClientRectangle);
}
else
{
base.OnPaintBackground(pe);
ControlPaint.DrawBorder3D(pe.Graphics, this.ClientRectangle, Border3DStyle.Raised);
}
}

Try creating your own customer UserControl

This answer is modified from another answer site. It does the trick rather cleanly.
In the load event for the window containing the tab control, try:
// TabControl is the name of the tab control in this window.
TabControl.Appearance = TabAppearance.FlatButtons;
TabControl.Multiline = false;
TabControl.SizeMode = TabSizeMode.Fixed;
TabControl.ItemSize = new Size(0,1);
// The tabs are now gone. Select the panel you want to display
TabControl.SelectTab("InProgressTab");