C# child form over main form having greyed out effect

问题

I want a child form to be displayed over main form with all the empty spaces around having some opacity. I achieved the same using the solution provided in C# winforms pop up with background faded.

Now I want the panel that is used in the child form to have rounded corner. Any help?

I used the panel from below link to have rounded corners. The panel is having rounded corner but still the rectangle line(highlighted in image) is visible. Is there any way to make it disappear ? http://www.openwinforms.com/creating_cool_gradient_panel_gdi.html

回答1:

I found the solution.

On form paint add:

 this.BackColor = Color.Lime;
        this.TransparencyKey = Color.Lime;

        var hb = new HatchBrush(HatchStyle.Percent60, this.TransparencyKey);
        e.Graphics.FillRectangle(hb, this.DisplayRectangle);

On form load make the panel edge round where ctrl = panel.

Rectangle bounds = new Rectangle(0, 0, ctrl.Width, ctrl.Height);
        int iCornerRadius = 20;
        GraphicsPath gpath = new GraphicsPath();
        gpath.AddArc(bounds.X, bounds.Y, iCornerRadius, iCornerRadius, 180, 90);
        gpath.AddArc(bounds.X + bounds.Width - iCornerRadius, bounds.Y, iCornerRadius, iCornerRadius, 270, 90);
        gpath.AddArc(bounds.X + bounds.Width - iCornerRadius, bounds.Y + bounds.Height - iCornerRadius, iCornerRadius, iCornerRadius, 0, 90);
        gpath.AddArc(bounds.X, bounds.Y + bounds.Height - iCornerRadius, iCornerRadius, iCornerRadius, 90, 90);
        gpath.CloseAllFigures();

        ctrl.Region = new Region(gpath);
        ctrl.Show();

来源：https://stackoverflow.com/questions/36855559/c-sharp-child-form-over-main-form-having-greyed-out-effect

标签

winforms

panel