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One property for multiple buttons

Is there a way to write in c# one property for multiple items. e.g. i have 5 buttons, i don't want to write button1.text = "etc", button2.text = "etc, I want to write button.text="etc" and have button1.text through button5.text to have "etc" text.

I guess this is feasible with something similar to:
public void SetButtonText(string value) {
this.Controls.OfType<Button>().ToList().ForEach(b => b.Text = value);
}
Or the same through a property:
public string ButtonText {
set {
Controls
.OfType<Button>()
.ToList()
.ForEach(b => b.Text = value);
}
}
EDIT
After a further research, I found out that there are no direct way to access the controls of a page in Windows Phone as I know. So it all depends on whether you wish to get down from the PhoneApplicationPage:
As I see it, your solution revolves around the Page.LogicalChildren Property.
public class MyPage : Page {
public string ButtonText {
set {
LogicalChildren
.OfType<Button>()
.ToList()
.ForEach(b => b.Text = value);
}
}
}
Since the LogicalChildren has a protected accessor, you need to access it through a derived class, which shall be convenient for any kind of page you're working on Windows Phone, I guess.
Or drop a Grid right onto the PhoneApplicationPage and then drop other controls over it such as your buttons, then you shall access them through the Grid.Children property.
So, having dropped your Grid and naming it myBaseGrid, one would do the following:
public void SetButtonsText(string text) {
myBaseGrid.Children
.OfType<Button>()
.ToList()
.ForEach(b => b.Text = "myText");
}
I would personally go with the method which name makes it clear what you're doing by spelling the word Button in plural as in my sample.

Perhaps you are looking for control arrays: http://msdn.microsoft.com/en-us/library/aa289500(v=vs.71).aspx?

You can't assign all 5 buttons to the same reference, so that button.text = "etc" will work.
You can however, bind the buttons to the same property:
<Button Content="{Binding myText}"/>
<Button Content="{Binding myText}"/>
<Button Content="{Binding myText}"/>
<Button Content="{Binding myText}"/>
If the binding is set properly with INotifyPropertyChanged, then all will update when myText is updated.
You could also put the controls into a collection and foreach over them to set their Content property as others have suggested.

One way would be to create a method that sets them all for you, which you would have to manually write once:
public void SetAllButtonTexts(string text)
{
button1.text = text;
button2.text = text;
// . . .
}
Alternatively you could use a loop:
public void SetAllButtonTexts(string btnText)
{
foreach (var control in this.Controls.OfType<Button>())
{
(control).Text = btnText;
}
}
And if you don't want to update ALL the buttons, one easy but not-so-elegant thing you could do is modify the Tag property of the buttons you want to change with some custom text, and only update those:
public void SetAllButtonTexts(string btnText, string tagText = "")
{
foreach (var control in this.Controls.OfType<Button>()
.Where(b => string.IsNullOrEmpty(tagText)
|| (b.Tag != null && b.Tag.Equals(tagText))))
{
(control).Text = btnText;
}
}

In a few words: Group up all your buttons which should get changed in a list. Then later loop through this list and set your text of all buttons.
Here's some code.
First of all:
public static List<Button> buttonList = new List<Button>{};
On form_load:
buttonList.AddRange(new List<Button>{ button1,button2,button3,...}); // Group your buttons
Now it depends on 'when' or 'where' you want to change it. If the buttons should be changed right in the beginning, put the following code into the form_load-event. Else when it should be fired on an event, place it into an event.
foreach(Button btn in buttonList)
{
btn.Text = "Change all button-texts from list at one time.";
}
You can also handle multiple lables or boxes etc. like this. Just declare the right datatype.
Greetings

TabControl AddingTab event

I have a TabControl in which I want to prevent adding existing TabPage (they are identified by a name) and instead set the SelectedTabPage to this precise tab.
I wish to know if there are an event that triggers right before a page is being added to the TabControl. If not, would using the event CollectionChanged of the TabPages (list) be a correct alternative ?

I believe the event you're looking for is the Control.ControlAdded event:
http://msdn.microsoft.com/en-us/library/system.windows.forms.control.controladded.aspx
If that also detects when things inside the tab pages themselves are added, you should be able to filter out everything but TabPage controls using the ControlEventArgs.Control property in your event handler.
To reject adding a control will be a little more complicated. Since this event seems to only be raised after the control gets added, you'll need to do something like this:
void onControlAdded(object sender, ControlEventArgs e) {
var tab = e as TabPage;
if (tab == null)
return;
this.myTabControlObject.TabPages.Remove(tab);
}
This should remove the tab, but it will likely slow the tab adding process considerably.

Try something like this, I am checking the TabControl page Collection for a page with the same name as the Page that is trying to be added, if it exists I am setting focus to the existing instance, otherwise adding the new page to the TabControl. See if something like this works for you.
private void button1_Click(object sender, EventArgs e)
{
TabPage tp = new TabPage();
tp.Name = tabPage1.Name;
var temp =tabControl1.Controls.Find(tp.Name,true);
if( temp.Length > 0)
{
tabControl1.SelectedTab = (TabPage) temp[0];
}
else
tabControl1.Controls.Add(tp);
}
Anything having to do with the ControlCollection will most likely be triggered after the control has been added.
From above link:
You can determine if a Control is a member of the collection by passing the control into the Contains method. To get the index value of the location of a Control in the collection, pass the control into the IndexOf method. The collection can be copied into an array by calling the CopyTo method.
If you want you could cleanup your code some by adding an ExtensionMethod to your TabControl Check for an existing page, set focus or add from there.
Example:
namespace ExtensionMethods
{
public static class MyExtensions
{
public static bool AddPage(this TabControl tc, TabPage tp)
{
var matchedPages = tc.Controls.Find(tp.Name, false);
if ( matchedPages.Length > 0)
{
tc.SelectedTab = (TabPage)matchedPages[0];
return true;
}
else
{
tc.TabPages.Add(tp);
tc.SelectedTab = tp;
return false;
}
}
}
}
Usage:
tabControl1.AddPage(tp);

C# Dynamic form (reflection) - linking controls

Sorry for the poor quality of the title. I couldn't think of a better way to phrase this.
For a project I'm currently working on with a few friends, I got myself in the situation where I have created a dynamic form (with reflection) which I now want to validate.
Example (ignore the black box, it contains old form elements which are now irrelevant and i didn't want to confuse you guys):
As you may have guessed already, it is an application for creating a mysql database.
Which is where I get to my problem(s). I want to disable checkboxes if others are checked.
For example: If I check "PrimaryKey" I want to disable the checkbox "Null".
Changing from unsigned to signed changes the numericupdown minimum and maximum etc.
But with reflection and all, I find it difficult to know exactly which checkbox to disable.
I was hoping you guys would have some suggestions.
I have been thinking about this for a while and a few thoughts have come to mind. Maybe these are better solutions than the current one.
Thought 1: I create UserControls for every datatype. Pro's: no problems with reflection and easy identifying of every control in the UserControl for validation. Con's: Copy-Pasting, Lots of UserControls, with a lot of the same controls.
Thought 2: Doing something with the description tags for every property of the classes. Creating rules in the description that allow me to link the checkboxes together. Here I'll only have to copy the rules to every class property and then it should be ok.
I had been thinking of other solutions but I failed to remember them.
I hope you guys can give me a few good pointers/suggestions.
[Edit]
Maybe my code can explain a bit more.
My code:
PropertyInfo[] properties = DataTypes.DataTypes.GetTypeFromString(modelElement.DataType.ToString()).GetType().GetProperties();
foreach (PropertyInfo prop in properties)
{
if (prop.Name != "Label" && prop.Name != "Project" && prop.Name != "Panel")
{
var value = prop.GetValue(modelElement.DataType, null);
if (value != null)
{
tableLayoutPanel1.Controls.Add(new Label { Text = prop.Name, Anchor = AnchorStyles.Left, AutoSize = true });
switch (value.GetType().ToString())
{
case "System.Int32":
NumericUpDown numericUpDown = new NumericUpDown();
numericUpDown.Text = value.ToString();
numericUpDown.Dock = DockStyle.None;
tableLayoutPanel1.Controls.Add(numericUpDown);
break;
case "System.Boolean":
CheckBox checkBox = new CheckBox();
checkBox.Dock = DockStyle.None;
// checkbox will become huge if not for these changes
checkBox.AutoSize = false;
checkBox.Size = new Size(16, 16);
if (value.Equals(true))
{
checkBox.CheckState = CheckState.Checked;
}
tableLayoutPanel1.Controls.Add(checkBox);
break;
default:
MessageBox.Show(#"The following type has not been implemented yet: " + value.GetType());
break;
}
}
}
}

Here is a mockup from my comments:
// The ViewModel is responsible for handling the actual visual layout of the form.
public class ViewModel {
// Fire this when your ViewModel changes
public event EventHandler WindowUpdated;
public Boolean IsIsNullCheckBoxVisible { get; private set; }
// This method would contain the actual logic for handling window changes.
public void CalculateFormLayout() {
Boolean someLogic = true;
// If the logic is true, set the isNullCheckbox to true
if (someLogic) {
IsIsNullCheckBoxVisible = true;
}
// Inform the UI to update
UpdateVisual();
}
// This fires the 'WindowUpdated' event.
public void UpdateVisual() {
if (WindowUpdated != null) {
WindowUpdated(this, new EventArgs());
}
}
}
public class TheUI : Form {
// Attach to the viewModel;
ViewModel myViewModel = new ViewModel();
CheckBox isNullCheckBox = new CheckBox();
public TheUI() {
this.myViewModel.WindowUpdated += myViewModel_WindowUpdated;
}
void myViewModel_WindowUpdated(object sender, EventArgs e) {
// Update the view here.
// Notie that all we do in the UI is to update the visual based on the
// results from the ViewModel;
this.isNullCheckBox.Visible = myViewModel.IsIsNullCheckBoxVisible;
}
}
The basic idea here is that you ensure that the UI does as little as possible. It's role should just be to update. Update what? That's for the ViewModel class to decide. We perform all of the updating logic in the ViewModel class, and then when the updating computations are done, we call the UpdateVisual() event, which tells the UI that it needs to represent itself. When the WindowUpdated Event occurs, the UI just responds by displaying the configuration set up by the ViewModel.
This may seem like a lot of work to set up initially, but once in place it will save you tons and tons of time down the road. Let me know if you have any questions.

Try relating the event of one checkbox to disable the other; something like this:
private void primaryKeyBox_AfterCheck(object sender, EventArgs e)
{
nullBox.Enabled = false;
}
This is a very simple example and would have to be changed a bit, but for what I think you're asking it should work. You would also have to add to an event for the boxes being unchecked. You would also need logic to only get data from certain checkboxes based on the ones that are and are not checked.
For all the other things, such as changing the numbers based on the dropdown, change them based on events as well.

For WinForms I would use data binding.
Create an object and implement INotifyPropertyChanged and work with that object.
Then, If you have an object instance aObj:
To bind the last name property to a textbox on the form do this:
Private WithEvents txtLastNameBinding As Binding
txtLastNameBinding = New Binding("Text", aObj, "LastName", True, DataSourceUpdateMode.OnValidation, "")
txtLastName.DataBindings.Add(txtLastNameBinding)
Take a look here for more info.
INotifyPropertyChanged

Is it possible to reverse the Context Menu items or reverse the sort

I am adding Context Items for a Context Menu and showing the required Items where necessary for the user based on user selection. I would like to show these context items for the user NEW and CLOSE..
I did some thing like
ContextMenu.Add(NEW)
ContextMenu.Add(CLOSE)
But I am getting this in sorted order like CLOSE first and NEW last . But I need to display NEW first and CLOSE last. Is it possible to do.

This (very basic code) should do it. Place following code in the constructor of your Form:
var contextMenu = new ContextMenu();
contextMenu.MenuItems.Add(new MenuItem("New"));
contextMenu.MenuItems.Add(new MenuItem("Close"));
this.ContextMenu = contextMenu;
Note: you still have to add the events yourself... :)
Update:
To add events to the items you'll have to declare them in a variable instead of passing them directly in the Add() method for the MenuItems. So the previous code will look like this:
var contextMenu = new ContextMenu();
var itemOne = new MenuItem("New");
itemOne.Click += ContextMenuItemClick;
contextMenu.MenuItems.Add(itemOne);
var itemTwo = new MenuItem("Close");
itemTwo.Click += ContextMenuItemClick;
contextMenu.MenuItems.Add(itemTwo);
ContextMenu = contextMenu;
As you can see, bot items have the same eventhandler for the Click-event. In that event you check which item was clicked. That code looks like this:
private void ContextMenuItemClick(object sender, EventArgs e)
{
var selectedItem = (MenuItem)sender;
switch(selectedItem.Text)
{
case "New" : //do some new stuff
break;
case "Close": //do some closing stuff
break;
}
}
Note that you could also set a separate eventhandler for each item in the menu, but then you end up with lots of methods for basically the same stuff... :) Hope this helps!
Update2:
With all the help I gave, you normally should have been able to achieve this by yourself, not? :) Anyway, for a separate handler the code will look like this:
itemOne.Click += itemOne_Click;
itemTwo.Click += itemTwo_Click;
private void itemOne_Click(object sender, EventArgs e)
{
//do the new stuff
}
private void itemTwo_Click(object sender, EventArgs e)
{
//do the closing stuff
}
Update3:
If you gave proper names to the menuitems you already added, you can change the order using the Index-property. Say I have following menuitems added to a ContextMenu:
var itemOne = new MenuItem("New") { Name = "NewItem" };
var itemTwo = new MenuItem("Close") { Name = "CloseItem" };
The 'NewItem' will be the first item and the 'CloseItem' will be the second. Now if I want to change the order without touching previous code you can do this:
contextMenu.MenuItems["NewItem"].Index = 1;
This will set the 'CloseItem' as the first and the 'NewItem' as the second. If you have more than 2 items, you better set the Index-property for each item individually.

How to disable a checkbox in a checkedlistbox?

I have some items in a CheckedListBox, I want to disable the CheckBox of first item in it.
i.e. I want to disable the first item in the CheckedListBox, because I want to tell the user visually that option is not available.

Combining 2 of the above partial answers worked great for me.
Add your items to the list with:
myCheckedListBox.Items.Add(myItem, myState);
Where myState is CheckState.Indeterminate for items that should be disabled.
Then add an event handler to keep those items from being changed:
myCheckedListBox.ItemCheck += (s, e) => { if (e.CurrentValue == CheckState.Indeterminate) e.NewValue = CheckState.Indeterminate; };
This does not allow you to use 'Indeterminate' in this list for its normal purpose but it does give a look very similar to what one would expect for a disabled item and it provides the correct behavior!

Though this post is pretty old, the last added answer has been submitted in April this year,
and I hope this will help someone.
I was after something similar : a checked list box that behaves like
a lot of installers, which offer a list of options where some features are required and
thus are both checked and disabled.
Thanks to this post (Can I use a DrawItem event handler with a CheckedListBox?)
I managed to do that, subclassing a CheckedListBox control.
As the OP in the linked post states, in the CheckedListBox control the OnDrawItem event is never fired,
so subclassing is necessary.
It's very basic, but it works.
This is what it looks like (the CheckBox above is for comparison) :
NOTE: the disabled item is really disabled : clicking on it has no effects whatsoever (as far as I can tell).
And this is the code :
public class CheckedListBoxDisabledItems : CheckedListBox {
private List<string> _checkedAndDisabledItems = new List<string>();
private List<int> _checkedAndDisabledIndexes = new List<int>();
public void CheckAndDisable(string item) {
_checkedAndDisabledItems.Add(item);
this.Refresh();
}
public void CheckAndDisable(int index) {
_checkedAndDisabledIndexes.Add(index);
this.Refresh();
}
protected override void OnDrawItem(DrawItemEventArgs e) {
string s = Items[e.Index].ToString();
if (_checkedAndDisabledItems.Contains(s) || _checkedAndDisabledIndexes.Contains(e.Index)) {
System.Windows.Forms.VisualStyles.CheckBoxState state = System.Windows.Forms.VisualStyles.CheckBoxState.CheckedDisabled;
Size glyphSize = CheckBoxRenderer.GetGlyphSize(e.Graphics, state);
CheckBoxRenderer.DrawCheckBox(
e.Graphics,
new Point(e.Bounds.X + 1, e.Bounds.Y + 1), // add one pixel to align the check gliph properly
new Rectangle(
new Point(e.Bounds.X + glyphSize.Width + 3, e.Bounds.Y), // add three pixels to align text properly
new Size(e.Bounds.Width - glyphSize.Width, e.Bounds.Height)),
s,
this.Font,
TextFormatFlags.Left, // text is centered by default
false,
state);
}
else {
base.OnDrawItem(e);
}
}
public void ClearDisabledItems() {
_checkedAndDisabledIndexes.Clear();
_checkedAndDisabledItems.Clear();
this.Refresh();
}
}
Use it like this:
checkedListBox.Items.Add("Larry");
checkedListBox.Items.Add("Curly");
checkedListBox.Items.Add("Moe");
// these lines are equivalent
checkedListBox.CheckAndDisable("Larry");
checkedListBox.CheckAndDisable(0);
Hope this can help someone.

Disabling items isn't a great idea, the user will have no good feedback that click the check box won't have any effect. You cannot use custom drawing to make it obvious. Best thing to do is to simply omit the item.
You can however easily defeat the user with the ItemCheck event:
private void checkedListBox1_ItemCheck(object sender, ItemCheckEventArgs e) {
if (e.Index == 0) e.NewValue = e.CurrentValue;
}

To disable any particular item use following:
checkedListBox1.SetItemCheckState(0, CheckState.Indeterminate);
SetItemCheckState takes index of item and CheckState Enum
Indeterminate is used to show shaded appearance

I know it has been a while, but I found this in my search for a list box and thought I would add it to the discussion.
If you have a listbox and want to disable all of the checkboxes so they cannot be clicked, but not disable the control so the user can still scroll etc. you can do this:
listbox.SelectionMode = SelectionMode.None

The CheckedListBox will not work in this way. CheckedListBox.Items is a collection of strings so they cannot be "disabled" as such.
Here are some discussions about possible solutions that might help you: here and here.

This works for me:
checkedListBox1.SelectionMode = SelectionMode.None;
Which means no items can be selected
None: No items can be selected.
For more info, you can check it here: SelectionMode Enumeration.

The solution is to use the event ItemChecking:
_myCheckedListBox.ItemChecking += (s, e) => e.Cancel = true;
This will cancel all the checking on every item, but you can always do more refined solution but testing the current .SelectedItem

Here's how I did it in a helpdesk application I wrote:
First, I made it so the check box was greyed out as I added it to the list during form load:
private void frmMain_Load(object sender, EventArgs e)
{
List<string> grpList = new List<string>();
ADSI objADSI = new ADSI();
grpList = objADSI.fetchGroups();
foreach (string group in grpList)
{
if (group == "SpecificGroupName")
{
chkLst.Items.Add(group, CheckState.Indeterminate);
}
else
{
chkLst.Items.Add(group);
}
}
Then I used an event so that when clicked it ensures it stays clicked:
private void chkLst_SelectedIndexChanged(object sender, EventArgs e)
{
if (chkLst.SelectedItem.ToString() == "SpecificGroupName")
{
chkLst.SetItemCheckState(chkLst.SelectedIndex, CheckState.Indeterminate);
}
}
The idea here is that on my form it's set so that the box checks on item click/select. This way I could kill two birds with one stone. I could keep this event from causing problems when the item is first checked and added during form load. Plus making it check on select allows me to use this event instead of the item checked event. Ultimately the idea is to keep it from messing up during the load.
You'll also notice that it doesn't matter what the index number is, that variable is unknown because in my app it's grabbing a list of groups from AD that exist in a specific OU.
As to whether this is a good idea or not, that's dependent on the situation. I have another app where the item to disable is dependent on another setting. In this app I just want the helpdesk to see that this group is required so they don't go removing them from it.

Try Below Code:
Private Sub CheckedListBox1_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles CheckedListBox1.MouseUp
If (Condition) Then
Me.CheckedListBox1.SelectedIndex = -1
End If
End Sub

I think an alternative solution, is using Telerik components.
A RadListControl can give you that option: