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POFlickering when showing a translucend custom Form via ShowDialog()
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  1. POFlickering when showing a translucend custom Form via ShowDialog()
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    copied!<p>I need to show a dialog form (<code>MessageForm</code>) over the main Form (<code>ParentForm</code>). The <code>MessageForm</code> contains a panel (<code>mainPanel</code>) on which I add some controls on runtime (the close button and many Labels and LinkLabels). MessageForm has a specific behavior: it must be translucent and, on show, the ParentForm must be inactive:</p> <pre><code>public MessageForm(FrmGlobalStatus _parent) { InitializeComponent(); this.TransparencyKey = this.BackColor; } protected override void OnPaintBackground(PaintEventArgs pe) { var hb = new HatchBrush(HatchStyle.Percent50, System.Drawing.ColorTranslator.FromHtml(HATCH_BACK_COLOR), this.TransparencyKey); pe.Graphics.FillRectangle(hb, this.DisplayRectangle); } private void mainPanel_Paint(object sender, PaintEventArgs pe) { using (System.Drawing.Pen p = new Pen(new SolidBrush(this.BorderColor))) { if (borderRadius &gt; 0) { DrawRoundRect(pe.Graphics, p, 0, 0, mainPanel.Width - 1, mainPanel.Height - 1, borderRadius, this.FillColor); } else { pe.Graphics.DrawRectangle(p, 0, 0, mainPanel.Width - 1, mainPanel.Height - 1); } } } </code></pre> <p>The function that shows the MessageForm:</p> <pre><code>public void Show() { LinkLabel newLinkLabel; Label newLabel; int lastItemBottom = 0; if (Items.Count &gt; 0) { for (int i = 0; i &lt; Items.Count; i++) { if (Items[i].LinkAreaLength != 0) { newLinkLabel = new LinkLabel(); newLinkLabel.Location = new Point(LINKLABEL_H_MARGIN, LINKLABEL_V_MARGIN + i * LINKLABEL_STEP); lastItemBottom = newLinkLabel.Bottom; newLinkLabel.BackColor = Color.Transparent; newLinkLabel.Text = Items[i].Text; newLinkLabel.LinkColor = LinkDefaultColor; newLinkLabel.ActiveLinkColor = LinkActiveColor; newLinkLabel.AutoSize = true; newLinkLabel.Links.Add(Items[i].LinkAreaStart, Items[i].LinkAreaLength, Items[i].URL); newLinkLabel.VisitedLinkColor = LinkVisitedColor; newLinkLabel.Name = LINK_LABEL_FAMILY + i.ToString(); newLinkLabel.LinkClicked += new LinkLabelLinkClickedEventHandler(LinkClicked); newLinkLabel.MouseHover += new EventHandler(Link_MouseHover); newLinkLabel.MouseLeave += new EventHandler(Link_MouseLeave); //for max label length calculation labelsWidth.Add(Convert.ToInt16((newLinkLabel.CreateGraphics().MeasureString(newLinkLabel.Text, newLinkLabel.Font)).Width)); this.mainPanel.Controls.Add(newLinkLabel); newLinkLabel.BringToFront(); } else { newLabel = new Label(); newLabel.Location = new Point(LINKLABEL_H_MARGIN, LINKLABEL_V_MARGIN + i * LINKLABEL_STEP); lastItemBottom = newLabel.Bottom; newLabel.BackColor = Color.Transparent; newLabel.Text = Items[i].Text; newLabel.Name = LABEL_FAMILY + i.ToString(); newLabel.AutoSize = true; //for max label length calculation labelsWidth.Add(Convert.ToInt16((newLabel.CreateGraphics().MeasureString(newLabel.Text, newLabel.Font)).Width)); this.mainPanel.Controls.Add(newLabel); newLabel.BringToFront(); } } //centering the mainPanel on MessageForm mainPanel.Width = BOX_WIDTH; mainPanel.Height = lastItemBottom + 2;// +LINKLABEL_V_MARGIN; mainPanel.Location = new Point((Width - mainPanel.Width) / 2, (Height - mainPanel.Height) / 2); ShowDialog(parent); } } </code></pre> <p>'Items' is alist of specific structures that already contains all the text for Label and <code>LinkLabel</code> controls. Well, now the problem: when I Call the <code>Show</code> function from <code>ParentForm</code>, my <code>MessageForm</code> is flickering, and it is enough visiblie for eyes disturbing. How can I eliminate this flickering? </p>
 

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