How to Delete selected control in Winforms C#?

Question

i need that when you click a garbage button, the "Selection mode" turn on (A bool variable became true) and when you click that control (let's say a button) the application "selects it" and with another button, (Ok button) the application should knew Wich controls you clicked, and then, delete them, the problem i Have is in the recognize witch controls you selected update For "selection" I mean that the app knows which control you clicked

Answer 1

You can implement the required functionality as follows. The idea is simple, to keep track of our last selection we have a "previousSelection" variable of type "Control" in our class. We can even use a list of type "Control" to keep track of multiple selections.

There's a toggle button to enable / disable "Garbage Mode" which maps to "IsGarbageModeEnabled" field of type "bool". Then we have an "InitControlsRecursiveMethod(ControlCollection collection)" which takes in a collection of controls, to which we would attach an event handler, which is "GenericClickHandler(Control c)" in our case. This handler simply updates the "previousSelection" on each button click.

And lastly we have our button "ConfirmDeletionBtn", upon clicking which, we would check whether "GarbageMode" is enabled or not, if it is, we would have some basic validation to check whether the control being deleted isn't our "Delete" or "GarbageModeToggle" button itself (this could cause trouble if user double clicks the 'Delete' button). Afterwards, it would remove / dispose the control that is to be deleted.

public partial class FormName : Form
{
    //To keep track of the previously selected control (i.e. to be deleted)
    private Control previousSelection { get; set; }

    //To keep track of whether "Garbage Mode" is enabled or disabled
    private bool IsGarbageModeEnabled { get; set; }

    //Constructor
    public FormName()
    {
        InitializeComponent();
        IsGarbageModeEnabled = false;
        previousSelection = new Control();

        //Attach a generic click handling event to each control to 
        //update "previousSelection" with each click.
        //Similar logic can be used for other events as well 
        //(e.g. GotFocus, which might even accomodate control selection via keyboard).
        InitControlsRecursive(this.Controls);
    }

    //This attaches the GenericClickHandler(Control c) to each control on the form.
    private void InitControlsRecursive(Control.ControlCollection collection)
    {
        foreach (Control c in collection)
        {
            c.MouseClick += (sender, e) => { GenericClickHandler(c); };
            InitControlsRecursive(c.Controls);
        }
    }

    //The generic click handling event we're using to update "previousSelection".
    private void GenericClickHandler(Control c)
    {
        previousSelection = c;
    }

    //By clicking the confirm deletion / OK button, we would delete the last selected control.
    private void ConfirmDeletionBtn_Click(object sender, EventArgs e)
    {
        if(IsGarbageModeEnabled == true)
        {
            if(previousSelection != ConfirmDeletionBtn || previousSelection != ToggleGarbageModeBtn)
            {
                this.Controls.Remove(previousSelection);
                previousSelection.Dispose();
            }
        }
    }

    //This is used to enable/disable Garbage Mode. Controls can be deleted only once it is enabled.
    private void ToggleGarbageModeBtn_Click(object sender, EventArgs e)
    {
        IsGarbageModeEnabled = !IsGarbageModeEnabled;
    }
}

Further Reading:

• Handling a click for all controls on a form
• Removing a control from a form

Answer 2

Firstly you need somewhere to keep track of the controls that were "selected" (clicked). So add this to the form's codebehind:

List<Control> _itemsToDelete = new List<Control>();

And you need a flag to indicate whether the user has activated garbage mode:

bool _garbageMode = false;

To activate garbage mode:

async void GarbageMode_Click(object sender, EventArgs e)
{
    _garbageMode = true;
}

Now when they "select" a control you add it to the list:

async void Control_Click(object sender, EventArgs e)
{
    if (_garbageMode)
    {
        _itemsToDelete.Add((Control)sender);
    }
}

Then to delete

foreach (var control in _itemsToDelete)
{
    this.Controls.Remove(control);
    control.Dispose();
}
_itemsToDelete.Clear();