Win Form waiting panel-CodePudding

I am programming a Windows form using C#. I have a waitform that I want to use when I am retrieving data from SQL. For example, I have a button called Refresh. When I press this button, it retrieves the data from the database again. So when I press the refresh button, the waitform opens and the data is loaded in the background. When the data loading is finished, the waitform will close.

Here is my code;

private void RefreshButton_Click(object sender, EventArgs e)
{
    
    using (WaitForm waitForm = new WaitForm())
    {
        
        Thread thread = new Thread(() => LoadData());
        
        thread.Start(waitForm);
        
        waitForm.ShowDialog();
    }
}

private void LoadData()
{
    // Some Entitys
}

in here because of waitForm.ShowDialog() my waitForm never close

CodePudding user response：

One of many ways to show a Winform waiting panel is to run the LoadData method on a Task and give the WaitFormWaitingPanel the ability to manage its own visibility.

public partial class MainForm : Form
{
    public MainForm()
    {
        InitializeComponent();
        buttonLoadData.Click  = onClickLoadData;
    }

    private async void onClickLoadData(object? sender, EventArgs e)
    {
        using (var waitForm = new WinFormWaitingPanel(this))
        {
            await Task.Run(() => LoadData());
        }
    }
    private void LoadData()
    {
        // Mock "any" long-running synchronous task
        // (SQL or otherwise)
        Thread.Sleep(TimeSpan.FromSeconds(1));
    }
}

Example

Semi-transparent wait form covers main form and provides wait cursor.

class WinFormWaitingPanel : Form
{
    public WinFormWaitingPanel(Form owner)
    {
        Owner = owner;
        
        // Size this form to cover the main form's client rectangle.
        Size = Owner.ClientRectangle.Size;
        FormBorderStyle = FormBorderStyle.None;
        UseWaitCursor = true;
        StartPosition = FormStartPosition.Manual;
        Location = PointToClient(
            Owner.PointToScreen(Owner.ClientRectangle.Location));

        // Add a label that says "Loading..."
        var label = new Label
        {
            Text = "Loading...",
            TextAlign = ContentAlignment.MiddleCenter,
            Dock = DockStyle.Fill,
        };
        Controls.Add(label);

        // Set the form color to see-through Blue
        BackColor = Color.LightBlue;
        Opacity = .5;

        var forceHandle = Handle;
        BeginInvoke(() => ShowDialog());
    }
}