Develop Reference

Checkbox save state using settings not working (winforms C#)

As you can see below, save code.
No errors at all.
Image
But when I change the state of the checkbox and close the form, the setting does not update and remains false.
Yes I do have something that uses the setting, and that works normally.

I am not following what the problem is. How are you “checking” if the setting is saved? In other words, I see nothing in your current code that actually USES the setting. I suggest you grab and apply the Properties CheckBox setting value to the CheckBox ExampleToggle when the form loads. Something like…
private void Form1_Load(object sender, EventArgs e) {
ExampleToggle.Checked = Properties.Settings.Default.CheckBox;
}
Also, in the future, posting pictures of code is frowned upon. You are forcing others who may help you into typing the code themselves. Many will just move on if they have to type the code.

Drag and drop event. Get the name of the control where the drag originated, whilst inside drop event method

I am attempting a drag and drop in WPF.
My program allows you to drag coloured labels around the screen, in essence giving you the effect that squares are being dragged and dropped.
Bearing in mind that only the text is dragged rather then the control itself (i.e. not the colour):
What I would like to achieve is that when the drop event fires, I can change the colour of the label which I dragged the text from.
After consulting MSDN I've failed to figure out how to get at the control in question and after plenty of trial and error I'm hoping somebody here can help. https://msdn.microsoft.com/en-us/library/system.windows.forms.drageventargs.data(v=vs.110).aspx
Below is a sample of code which works, but the label who's colour I want to change is hard-coded, whereas in reality it could be any one of a number of labels.
private void ObjDrop(object sender, DragEventArgs e)
{
//testSquare is a hardcoded label
testSquare.Background = Brushes.LimeGreen;
//what I really need is for a variable to detect which label to access each time before I change its colour. So something along the lines of
Label myLabel = someCodeToGetTheLabelThatWasDragged;
myLabel.Background = Brushes.LimeGreen;
}
Hopefully I explained things well enough, thanks in advance.

You would use the IDataObject.GetData(Type) method to extract the the object in DragEventArgs.Data property. From there, you should be able to access whatever you store in the IDataObject.
This is a pretty general answer. To achieve said answer, that means you'll have to write your own class that implements IDataObject which contains the original control/control's name etc., then set the IDataObject when drag in initialized.
There may be an alternate solution available. I would watch what e.Data is in your current example, and try to work with that. If e.Data is of type Label, through casting, you could access the label that way, e.g. (e.Data as Label).Background = Brushes.LimeGreen;.
In a Drag and Drop implementation I've seen, the IDataObject contains the DropTarget and the DragSource, that way you can compare the two and allow/disallow things/types from being dragged and dropped by setting the Effect.

This page provides the solution for what i'm looking to do.
WPF Drag and Drop - Get original source info from DragEventArgs
The following code in particular used in the drop event method allowed me to achieve my aim
Label lbl = e.Data.GetData("System.Windows.Controls.Label") as Label;
After that I could manipulate the source of the drag whatever way I wished.

Setting description of an item in Visual Studio -and- changing what "this" refers to

I'm working in Visual Studio 2010 and I'm dealing with C#; I've made a statusStrip that I intend to use as my tool-tip viewer, its .text attribute changing depending on the control the mouse has entered. I've got two textBoxes and I'm trying to make it such that entering the control fires a function called tooltipEnter, and leaving it fires a function called tooltipLeave. Here's my code for those two functions:
private void tooltipEnter(object sender, EventArgs e)
{
toolStripStatusLabel1.Text = this.AccessibleDescription;
}
private void tooltipLeave(object sender, EventArgs e)
{
toolStripStatusLabel1.Text = "Look here for tool-tips regarding the form!";
}
The problem with this is that, first, I'm not sure AccessibleDescription is the right attribute to saddle the description to, and I'm not sure of the most elegant way to do the toolStripStatusLabel1.Text assignment in the first place. Second, this in the program's frame of reference refers to the form on which these controls lay, not the controls themselves; How do I refer uniformly to "the control that just got entered" in a way that allows me to have just the one function for all entries, without having to make different ones for each control?

The problem with this is that, first, I'm not sure
AccessibleDescription is the right attribute to saddle the description
to, and I'm not sure of the most elegant way to do the
toolStripStatusLabel1.Text assignment in the first place.
AccessibleDescription is just some string instance referenced in your form, from this code. The text assignment is done in the only way possible. I'm not sure what your question is regarding this.
Second, this in the program's frame of reference refers to the form on
which these controls lay, not the controls themselves; How do I refer
uniformly to "the control that just got entered" in a way that allows
me to have just the one function for all entries, without having to
make different ones for each control?
sender is always the object from which the event was raised in the EventHandler delegate: msdn.microsoft.com/en-us/library/system.eventhandler.aspx

How can I pass data through a DragDrop event?

I have very little experience making my own events. I'm currently using forms and controls to handle events, so I'm trying to stick to the WinForm way of dealing with events.
WinForm controls already have their own events. Since events are made with a certain delegate type, I have to match the delegate signature in the methods I use to handle what goes on during an event. As far as I can tell, this means I have to take in two parameters in my event handlers: a source Object and an EventArgs.
I'm trying to figure out how to pass various information between controls through DragDrop related events. I've been able to find various code snippets online for different situations, but I'd like to have a better understanding of how the information is actually passed around.
When it comes to DragDrop events in particular, it seems my information will be passed through a DataObject. That, in turn, is passed as a parameter to the DragDrop.DoDragDrop method.
This is where my understanding starts to diminish. In most examples I've seen, it looks like some sort of data format is specified. The data format itself is of type string. Usually the data format is passed along with the data into the DataObject.
What is this data format doing? Is it just showing the type of the data involved? I've seen examples where the data format was tested, and various actions took place depending on what the data format had been. Couldn't you just do a typeof(YourData) to check for the type? I don't understand how a data format is useful.
http://msdn.microsoft.com/en-us/library/ms741842.aspx
In the above link, the first example shows a DataObject being created with no data format being specified. It explains that the data format is automatically chosen and that your object is converted by default.
Can you just pass any object into the DataObject? Then when the DragDrop event takes place on the target control, can that control access the methods and fields of the object passed? Or will the object be converted into some other form by the DataObject? How about various structures?
I've also done some drag and dropping from a Windows explorer icon to my forms. I was able to get the icon's file path with some example code I found. It also used a data format.
if (e.Data.GetDataPresent(DataFormats.FileDrop))
{
e.Effect = DragDropEffects.Copy;
}
SUMMARY:
I'm trying to get an understanding of how data is passed through WinForm events. I don't understand some of what I've seen in various DragDrop examples. I understand that data is somehow stored in various formats, and that there is a way to extract that data. I don't understand what a data format is used for. I don't understand exactly what sorts of data can be transferred through a DataObject. My understanding of EventArgs in general is fairly lacking.
Feel free to comment on anything I've mentioned here. If I stated something incorrectly, point it out. Anything that will help me understand this subject better is appreciated.
EDIT:
I decided to explain where I plan to go with this. Maybe someone can use what I'm trying to do as a way to explain some of what I asked.
I have a form that contains a certain type of control. I'm trying to make the placement of the controls highly customizable and dynamic. Whenever another control is added to the form by the user, every control is automatically repositioned to keep things orderly.
I'm currently trying to allow the user to drag a control around the Form to resposition it. Wherever the user decides to drop the control, all of the other controls will move out of the way to make room for the move control.
If I'm going to be able to move the dragged control and all the other controls on the form properly, I need to be able to get certain information from the dragged control. The main data that would need to be passed through the events would take the form of a Location property that uses a System.Drawing.Point structure.

Here's something to give you an idea of how it's done.
First drop two panels on a Form, and set their colors to two different colors.
public Form1()
{
InitializeComponent();
panel1.MouseDown += new MouseEventHandler(panel1_MouseDown);
panel2.AllowDrop = true;
panel2.DragEnter += new DragEventHandler(panel2_DragEnter);
panel2.DragDrop += new DragEventHandler(panel2_DragDrop);
}
void panel1_MouseDown(object sender, MouseEventArgs e)
{
panel1.DoDragDrop(panel1, DragDropEffects.Move);
}
void panel2_DragEnter(object sender, DragEventArgs e)
{
if (e.Data.GetData(typeof(Panel)) != null) e.Effect = DragDropEffects.Move;
}
void panel2_DragDrop(object sender, DragEventArgs e)
{
Panel p = sender as Panel;//Not needed in this case. Could just write panel2.
Panel dropped = (Panel)e.Data.GetData(typeof(Panel));
dropped.Location = p.PointToClient(new Point(e.X, e.Y));
p.Controls.Add(dropped);
}
Then drag panel1 onto panel2.

I think this problem should not be solved using drag&drop. Drag&drop is meant as a way for multiple applications to exchange data. If the data you are dragging is only meaningful for the current process, don't use drag&drop.
You can just use a field (for example, a field on the instance of the containing Form) to store all the data you need.
Just to say the obvious: Drag&drop is not a way to drag around controls. You need a lot of custom logic for that, anyway. It's not like the built-in features of dnd would help you here.

How to distinguish between User Control load on form and load when runtime

I created a user control using C# for windows form application. This user control has some properties. In runtime, if the user does not enter values for this properties I want to show a message box and exit the application.
The problem is when I write the checking code in the Load event of User Control. When I drag & drop it on the form the message box will appear.
private void UserControl1_Load(Object sender, EventArgs e)
{
if (_getFirstPageArgument==null || _getFirstPageArgument.Length==0)
{
throw new Exception("Some Message");
}
}
How do I distinguish between load on the form and load on run time?

I fear there is a larger problem here. But to solve your immediate problem (if I understand correctly...) There is a form attribute called DesignMode. When you are in the visual studio design mode, this will be true. At runtime, this will be false.

For beginners, #Nimas case can be a good study point to understand that Visual Studio actually runs and executes parts of our code even when we are in design time, which is why the constructor is invoked. Even "DesignMode" property is not 100% reliable. You can find an interesting note here related to that http://weblogs.asp.net/fmarguerie/archive/2005/03/23/395658.aspx

If you only want to know when the type itself has been loaded into the runtime (not a specific instance), you can put code into the static constructor for that class.
If I'm misinterpreting your question, please clarify using a timeline when you want specific events to happen.