How can I set the opacity or transparency of a Panel in WinForms?

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I was wondering how to change or modify the transparency of a Panel in C#, not the whole form, but the panel only.. I've seen many C# tutorials on Opacity, but its for the Form. im looking for how it could be possible with the Panel only. Thank You!

Yes, opacity can only work on top-level windows. It uses a hardware feature of the video adapter, that doesn't support child windows, like Panel. The only top-level Control derived class in Winforms is Form.

Several of the 'pure' Winform controls, the ones that do their own painting instead of letting a native Windows control do the job, do however support a transparent BackColor. Panel is one of them. It uses a trick, it asks the Parent to draw itself to produce the background pixels. One side-effect of this trick is that overlapping controls doesn't work, you only see the parent pixels, not the overlapped controls.

This sample form shows it at work:

public partial class Form1 : Form {
    public Form1() {
        InitializeComponent();
        this.BackColor = Color.White;
        panel1.BackColor = Color.FromArgb(25, Color.Black);
    }
    protected override void OnPaint(PaintEventArgs e) {
        e.Graphics.DrawLine(Pens.Yellow, 0, 0, 100, 100);
    }
}

If that's not good enough then you need to consider stacking forms on top of each other. Like this.

Notable perhaps is that this restriction is lifted in Windows 8. It no longer uses the video adapter overlay feature and DWM (aka Aero) cannot be turned off anymore. Which makes opacity/transparency on child windows easy to implement. Relying on this is of course future-music for a while to come. Windows 7 will be the next XP :)

Any trick to use opacity on a panel in Visual Studio Window Form , Please subcribe and like for support us For more info please comment feel free ^​_^ Thank you.Duration: 1:37 Posted: Jul 24, 2019 The Opacity property enables you to specify a level of transparency for the form and its controls. When this property is set to a value less than 100 percent (1.00), the entire form, including borders, is made more transparent. Setting this property to a value of 0 percent (0.00) makes the form completely invisible.

For whoever is still looking for a totally transparent panel, I found a nice solution in this blog by William Smash who in turn has taken it from Tobias Hertkorn on his T# blog. I thought its worth posting it as an answer here.

C# code:
public class TransparentPanel : Panel
{
    protected override CreateParams CreateParams 
    {            
        get {
            CreateParams cp =  base.CreateParams;
            cp.ExStyle |= 0x00000020; // WS_EX_TRANSPARENT
            return cp;
            }
    }
    protected override void OnPaintBackground(PaintEventArgs e) 
    {
        //base.OnPaintBackground(e);
    }
}
VB.Net code:
Public Class TransparentPanel
Inherits Panel
    Protected Overrides ReadOnly Property CreateParams() As System.Windows.Forms.CreateParams
        Get
            Dim cp As CreateParams = MyBase.CreateParams
            cp.ExStyle = cp.ExStyle Or &H20 ''#WS_EX_TRANSPARENT
            Return cp
        End Get
    End Property
    Protected Overrides Sub OnPaintBackground(ByVal e As System.Windows.Forms.PaintEventArgs)
    ''#MyBase.OnPaintBackground(e)
    End Sub
End Class

How to set the opacity or transparency of a Panel in C# Winform .NET, Hello, frnds in this video u can learn how to make transparent panel and best design in c# . Don Duration: 5:46 Posted: Aug 12, 2018 How to set the opacity or transparency of a Panel in C# Winform .NET lombarobot id. C# WinForms Tutorial 1 How To Make Transparent Color In Visual Basic.Net

Based on information found at http://www.windows-tech.info/3/53ee08e46d9cb138.php, I was able to achieve a translucent panel control using the following code.

public class TransparentPanel : Panel
{
    protected override CreateParams CreateParams
    {
        get
        {
            var cp = base.CreateParams;
            cp.ExStyle |= 0x00000020; // WS_EX_TRANSPARENT

            return cp;
        }
    }

    protected override void OnPaint(PaintEventArgs e) =>
        e.Graphics.FillRectangle(new SolidBrush(this.BackColor), this.ClientRectangle);
}

The caveat is that any controls that are added to the panel have an opaque background. Nonetheless, the translucent panel was useful for me to block off parts of my WinForms application so that users focus was shifted to the appropriate area of the application.

How to make transparent panel in c#, For example, you put a Panel on a Form. If you set the BackColor of the Panel to Transparent, the Panel will take on the BackColor property of  As far as I know a Panel can have a transparent color only, you can not control the opacity of the panel. So, you can have some parts of a panel completely transparent but not a 50% to say something. To use transparency you must define the transparent color property.

Don't forget to bring your Panel to the Front when dynamically creating it in the form constructor. Example of transparent panel overlay of tab control.

panel1 = new TransparentPanel();
panel1.BackColor = System.Drawing.Color.Transparent;
panel1.Location = new System.Drawing.Point(0, 0);
panel1.Name = "panel1";
panel1.Size = new System.Drawing.Size(717, 92);
panel1.TabIndex = 0;
tab2.Controls.Add(panel1);
panel1.BringToFront(); 

// <== otherwise the other controls paint over top of the transparent panel

[Solved] Winforms C# make a panel background transparent , Yes, you are able to set the Background color of controls to Transparent, but this causes the control to be completely see-through. What if you  Try this: panel1.BackColor = Color.FromArgb ( 100, 88, 44, 55); change alpha (A) to get desired opacity. Yes, opacity can only work on top-level windows. It uses a hardware feature of the video adapter, that doesn't support child windows, like Panel. The only top-level Control derived class in Winforms is Form.

As far as I know a Panel can have a transparent color only, you can not control the opacity of the panel. So, you can have some parts of a panel completely transparent but not a 50% to say something.

To use transparency you must define the transparent color property.

Creating a .NET Transparent Panel, Yes, you are able to set the Background color of controls to Transparent, but this causes the control to be completely see-through. What if you  Public Class TransparentPanel Inherits System.Windows.Forms.Panel Protected Overrides ReadOnly Property CreateParams() As CreateParams Get ' Make background transparent Dim cp As CreateParams = MyBase.CreateParams cp.ExStyle = cp.ExStyle Or &H20 Return cp End Get End Property Protected Overrides Sub OnPaintBackground(e As PaintEventArgs) ' call MyBase.OnPaintBackground(e) only if the backColor is not Color.Transparent If Me.BackColor <> Color.Transparent Then MyBase.OnPaintBackground(e) End

Creating a .NET Transparent Panel, After that I place a Panel control on the Form and set background color of the Panel to red. Now I set Form's TransparentKey property to the same  So, what you can do is take your background image, and paint the transparent area with a specific color (Magenta always seemed appropriate to me). Set the image as the Form's BackgrounImage property, and set the color as the Form's TransparencyKey. No need for changes in the Control's style, and no need for BackColor.

Transparent Panel in C#, I want to make a panel semi-transparent. 1)Instead of setting backcolor to transparent, use a copyfromscreen function to create a bitmap of  Create the Custom Panel Class. Now the TransparentMessagePanel has been compiled it will show up in the toolbox. Search for Transpar to shorten the list. Add A TransparentMessagePanel to the Form and resize it to overlay all the other components.

How to make a semi-transparent panel? - MSDN, Transparent. You should note that in WinForms transparency actually means that the back color of the control is set to the color(s) of the parent 

Comments
  • I've posted a comparison of renders on Windows 7 and old Windows 2003 stackoverflow.com/a/32075941/1529139
  • And also on Win8 and Higher. From MSDN Windows 8: The WS_EX_LAYERED style is supported for top-level windows and child windows. Previous Windows versions support WS_EX_LAYERED only for top-level windows.
  • This is great, 1 Question: is there a way to shade the form? So we currently have a completely transparent panel, but can we shade it slightly so that the user can be focused to a part we define?
  • Ive applied this panel to a form and onPaintBackground i draw the cliprect in opaque color, but underneath i have other controls on the form, which seem to overdraw this new panel, even though the panel is put on the form controls and my other custom controls are put on another panel. do I need to do anything specific in my custom controls to allow drawing over the top?
  • This does not work for me. The panel is transparent and does not have the color shown from the OnPaint. Are you sure that's the whole class?
  • Ok I got it to sort of work. But it only worked if I had absolutely no controls on the panel. And all controls behind the panel still display pretty much normally so it effectively just tints the background under the panel. Which is basically useless as an "overlay".
  • For those of you who aren't too good with the 0-255 color schematics, you can use this: panel1.BackColor = Color.FromArgb(50, Color.Green);
  • I can't seem to make it work. Changing the alpha layer makes the color of the Panel darker or lighter, but I can't ever see the controls behind it. Am I missing something?
  • This does not work. See this answer.
  • This DOES work! I've just used it, making my Panel semi transparent on my splash screen
  • Doesn't seem to work on Windows 10.