I'm using the AnimateWindow API to show or hide a Form with a slide animation. The problem is that if the Form contains a RichTextBox control, it doesn't display this control correctly. It's transparent and doesn't show any text.
After the animation is complete, double clicking somewhere in the control will reveal lines of text.
I've created a full sample that anyone can use to compile and test themselves. There's no better way to debug this, unless you already know the answer.
There's 2 buttons in the main form, one to show another form and the other to hide that same form. I've added both the RichTextBox as a simple TextBox. As you'll see, the problem only happens on the RichTextBox.
using System;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;
namespace WindowsFormsApplication1 {
static class Program {
public const int AW_ACTIVATE = 0x00020000;
public const int AW_HIDE = 0x00010000;
public const int AW_HOR_NEGATIVE = 0x00000002;
public const int AW_HOR_POSITIVE = 0x00000001;
public const int AW_SLIDE = 0x00040000;
[DllImport("user32")]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool AnimateWindow(IntPtr hWnd, int time, int awFlags);
[STAThread]
public static void Main() {
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}
}
public class Form1 : Form {
public Form form;
public Form1() {
InitializeComponent();
form = new Form2();
form.Show();
form.Hide();
}
private void button1_Click(object sender, EventArgs e) {
form.Location = new Point(Location.X, Location.Y + form.Height + 100);
Program.AnimateWindow(form.Handle, 1000, Program.AW_SLIDE | Program.AW_HOR_NEGATIVE | Program.AW_ACTIVATE);
form.Show();
}
private void button2_Click(object sender, EventArgs e) {
Program.AnimateWindow(form.Handle, 1000, Program.AW_HIDE | Program.AW_HOR_POSITIVE);
form.Hide();
}
#region Windows Form Designer generated code
private void InitializeComponent() {
this.button1 = new System.Windows.Forms.Button();
this.button2 = new System.Windows.Forms.Button();
this.SuspendLayout();
this.button1.Font = new System.Drawing.Font("Microsoft Sans Serif", 14.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
this.button1.Location = new System.Drawing.Point(11, 12);
this.button1.Name = "button1";
this.button1.Size = new System.Drawing.Size(133, 114);
this.button1.TabIndex = 0;
this.button1.Text = "SHOW";
this.button1.UseVisualStyleBackColor = true;
this.button1.Click += new System.EventHandler(this.button1_Click);
this.button2.Font = new System.Drawing.Font("Microsoft Sans Serif", 14.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
this.button2.Location = new System.Drawing.Point(150, 12);
this.button2.Name = "button2";
this.button2.Size = new System.Drawing.Size(133, 114);
this.button2.TabIndex = 1;
this.button2.Text = "HIDE";
this.button2.UseVisualStyleBackColor = true;
this.button2.Click += new System.EventHandler(this.button2_Click);
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(294, 138);
this.Controls.Add(this.button2);
this.Controls.Add(this.button1);
this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;
this.MaximizeBox = false;
this.MinimizeBox = false;
this.Name = "Form1";
this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
this.Text = "Form1";
this.ResumeLayout(false);
}
#endregion
private System.Windows.Forms.Button button1;
private System.Windows.Forms.Button button2;
}
public class Form2 : Form {
public Form2() {
InitializeComponent();
}
#region Windows Form Designer generated code
private void InitializeComponent() {
System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(Form2));
this.richTextBox1 = new System.Windows.Forms.RichTextBox();
this.textBox1 = new System.Windows.Forms.TextBox();
this.SuspendLayout();
this.richTextBox1.Dock = System.Windows.Forms.DockStyle.Top;
this.richTextBox1.Location = new System.Drawing.Point(0, 0);
this.richTextBox1.Name = "richTextBox1";
this.richTextBox1.Size = new System.Drawing.Size(240, 50);
this.richTextBox1.TabIndex = 0;
this.richTextBox1.Text = "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.";
this.textBox1.Dock = System.Windows.Forms.DockStyle.Bottom;
this.textBox1.Location = new System.Drawing.Point(0, 57);
this.textBox1.Multiline = true;
this.textBox1.Name = "textBox1";
this.textBox1.ScrollBars = System.Windows.Forms.ScrollBars.Vertical;
this.textBox1.Size = new System.Drawing.Size(240, 50);
this.textBox1.TabIndex = 1;
this.textBox1.Text = "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.";
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(240, 107);
this.ControlBox = false;
this.Controls.Add(this.textBox1);
this.Controls.Add(this.richTextBox1);
this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;
this.Name = "Form2";
this.StartPosition = System.Windows.Forms.FormStartPosition.Manual;
this.Text = "Form2";
this.ResumeLayout(false);
this.PerformLayout();
}
#endregion
private System.Windows.Forms.RichTextBox richTextBox1;
private System.Windows.Forms.TextBox textBox1;
}
}
NOTE: I'm starting a bounty on this so if you're going to answer, please answer with a solution that works and not something for me to try and see if it works. Why? Because if people upvote your answer and doesn't fix anything , it will still be marked as accepted which it didn't help. Thanks for understanding.