Transparent control on the painted form

Question

Transparent control on the painted form

Using C # WinForms I have a form in which I draw a gradient background from blue to blue on it. I have several buttons and several shortcuts on which I have already tried setting the reverse color to transparent , since I want the background to appear - especially for shortcuts, but it doesn't seem to work.

But I noticed that the picture is also superimposed, although the code is present only in the form_paint event.

How can I make the labels not the same shading, but transparent? for example, the labels at the top of the form will be light blue and the bottom will be dark blue.

private void frmOptions_Paint(object sender, PaintEventArgs e)
{
    e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
    Rectangle rectangle = e.ClipRectangle;

    using (Brush aBrush = new LinearGradientBrush(rectangle, Color.LightBlue, Color.DarkBlue, LinearGradientMode.Vertical))
    {
        e.Graphics.FillRectangle(aBrush, rectangle);
    }
}

Thanks so much for any help with this.

EDIT: , EACH - , 2 . , .

2: (. ), , paint . , "Rectangle rectangle = e.ClipRectangle;" - . ClipRectangle - ... ? , , , Reniuz.

3 cliprightangle "Rectangle rectangle = new Rectangle(0, 0, this.Width, this.Height);". , , , - 7, 8 :( , "TransparentLabel", .

+3

c# winforms gdi

harag 09 . '11 15:15

1

Reniuz · Accepted Answer · 2011-06-09T19:29:49+0000

.

Edit:

:

public class TransparentLabel : Control
{
    public TransparentLabel(Label label)
    {
        //setting default properties
        this.Text = label.Text;
        this.Font = label.Font;
        this.Location = label.Location;
        this.Size = label.Size;
        this.Parent = label.Parent;
        this.BringToFront();
        label.Dispose();

        TabStop = false;
    }

    protected override CreateParams CreateParams
    {
        get
        {
            CreateParams cp = base.CreateParams;
            cp.ExStyle |= 0x20;
            return cp;
        }
    }

    protected override void OnPaintBackground(PaintEventArgs e)
    {
        // do nothing
    }

    protected override void OnPaint(PaintEventArgs e)
    {
        DrawText();
    }

    protected override void WndProc(ref Message m)
    {
        base.WndProc(ref m);
        if(m.Msg == 0x000F)
        {
            DrawText();
        }
    }

    private void DrawText()
    {
        using(Graphics graphics = CreateGraphics())
        using(SolidBrush brush = new SolidBrush(ForeColor))
        {
            SizeF size = graphics.MeasureString(Text, Font);

            // first figure out the top
            float top = 0;
            switch(textAlign)
            {
                case ContentAlignment.MiddleLeft:
                case ContentAlignment.MiddleCenter:
                case ContentAlignment.MiddleRight:
                    top = (Height - size.Height) / 2;
                    break;
                case ContentAlignment.BottomLeft:
                case ContentAlignment.BottomCenter:
                case ContentAlignment.BottomRight:
                    top = Height - size.Height;
                    break;
            }

            float left = -1;
            switch(textAlign)
            {
                case ContentAlignment.TopLeft:
                case ContentAlignment.MiddleLeft:
                case ContentAlignment.BottomLeft:
                    if(RightToLeft == RightToLeft.Yes)
                        left = Width - size.Width;
                    else
                        left = -1;
                    break;
                case ContentAlignment.TopCenter:
                case ContentAlignment.MiddleCenter:
                case ContentAlignment.BottomCenter:
                    left = (Width - size.Width) / 2;
                    break;
                case ContentAlignment.TopRight:
                case ContentAlignment.MiddleRight:
                case ContentAlignment.BottomRight:
                    if(RightToLeft == RightToLeft.Yes)
                        left = -1;
                    else
                        left = Width - size.Width;
                    break;
            }
            graphics.DrawString(Text, Font, brush, left, top);
        }
    }

    public override string Text
    {
        get
        {
            return base.Text;
        }
        set
        {
            base.Text = value;
            RecreateHandle();
        }
    }

    public override RightToLeft RightToLeft
    {
        get
        {
            return base.RightToLeft;
        }
        set
        {
            base.RightToLeft = value;
            RecreateHandle();
        }
    }

    public override Font Font
    {
        get
        {
            return base.Font;
        }
        set
        {
            base.Font = value;
            RecreateHandle();
        }
    }

    private ContentAlignment textAlign = ContentAlignment.TopLeft;
    public ContentAlignment TextAlign
    {
        get { return textAlign; }
        set
        {
            textAlign = value;
            RecreateHandle();
        }
    }
}

, :

TransparentLabel transparentLabel1 = new TransparentLabel(label1);
TransparentLabel transparentLabel2 = new TransparentLabel(label2);

( , ):

Transparent control on the painted form

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