Winforms: Controls not visible after added programmatically - winforms

Question

I want to create a simple FileExplorer Control for a video player.
Here is the code:
namespace CustomControls
{
public interface IScrollable
{
float visiblePercent { get; set; }
float ScrollSpeedMultiplier { get; set; }
int scrollValue { get; set; }
CustomScrollBar scrollBar { get; set; }
}
}
namespace CustomControls {
public partial class ScrollablePanel : UserControl, IScrollable {
private int _scrollValue;
private int _totalWheelDelta;
private int totalWheelDelta {
get => _totalWheelDelta;
set {
SetTotalDelta(value);
}
}
public int Count => panelInner.Controls.Count;
public bool VisibleControls => panelInner.Controls.OfType<Panel>().All(p => p.Visible);
public float visiblePercent { get; set; }
public int scrollValue {
get { return _scrollValue; }
set {
_scrollValue = value;
if (scrollBar != null && scrollBar.value != _scrollValue)
scrollBar.value = _scrollValue;
SetTotalDeltaByScrollValue(value);
ScrollThrough();
}
}
[EditorBrowsable(EditorBrowsableState.Always), Browsable(true), DefaultValue(0), Category("Behavior"), Description("Die dazugehörige Scrollbar")]
public CustomScrollBar scrollBar { get; set; }
public float ScrollSpeedMultiplier { get; set; }
public ScrollablePanel() {
InitializeComponent();
panelInner.MouseWheel += panelInner_MouseWheel;
}
protected override ControlCollection CreateControlsInstance() {
return new ScrollablePanelElementCollection(this, this.panelInner);
}
private void ScrollablePanel_Load(object sender, EventArgs e) {
OnControlsChanged();
}
private void panelInner_MouseWheel(object sender, MouseEventArgs e) {
if (visiblePercent >= 1.0f)
return;
totalWheelDelta += (int)(e.Delta * ScrollSpeedMultiplier);
scrollValue = (100 * SystemInformation.MouseWheelScrollLines * totalWheelDelta) / ((Height - panelInner.Height) * SystemData.scrollDeltaModifier);
if (scrollBar != null)
scrollValue = scrollBar.value = (100 * SystemInformation.MouseWheelScrollLines * totalWheelDelta) / ((Height - panelInner.Height) * SystemData.scrollDeltaModifier);
}
private void ScrollThrough() {
panelInner.Location = new Point(0, (int)((Height - panelInner.Height) * (scrollValue / 100.0f)));
}
private void panelInner_ControlAdded(object sender, ControlEventArgs e) {
OnControlsChanged();
}
private void panelInner_ControlRemoved(object sender, ControlEventArgs e) {
OnControlsChanged();
}
private void OnControlsChanged() {
int height = int.MinValue;
foreach (Control control in panelInner.Controls)
if (control.Visible)
height = Math.Max(height, control.Bottom);
panelInner.Height = height;
ScrollablePanel_Resize(this, new EventArgs());
if (panelInner.Height > 0)
visiblePercent = (float)Height / panelInner.Height;
else
visiblePercent = 1.0f;
if (scrollBar != null)
scrollBar.largeChange = (int)(visiblePercent * 100);
}
private void ScrollablePanel_Resize(object sender, EventArgs e) {
panelInner.Width = Width;
}
private void SetTotalDelta(int value) {
int lines = SystemInformation.MouseWheelScrollLines * (value / SystemData.scrollDeltaModifier);
int deltaHeight = Height - panelInner.Height;
if (lines > 0)
_totalWheelDelta = 0;
else if (lines < deltaHeight)
_totalWheelDelta = (deltaHeight * SystemData.scrollDeltaModifier) / SystemInformation.MouseWheelScrollLines;
else
_totalWheelDelta = value;
}
private void SetTotalDeltaByScrollValue(int value) {
int deltaHeight = Height - panelInner.Height;
totalWheelDelta = (deltaHeight * SystemData.scrollDeltaModifier * scrollValue) / (100 * SystemInformation.MouseWheelScrollLines);
}
public void Clear() {
panelInner.Controls.Clear();
}
}
public class ScrollablePanelElementCollection : Control.ControlCollection {
private Control container;
public ScrollablePanelElementCollection(Control owner, Panel container) : base(owner) { this.container = container; }
public override void Add(Control value) {
if (this.Count == 0)
base.Add(value);
else
container.Controls.Add(value);
}
}
}
namespace MagererPlayer {
public partial class FileExplorer : UserControl, IScrollable {
private string _directory;
public float visiblePercent {
get => scrollablePanel.visiblePercent;
set => scrollablePanel.visiblePercent = value;
}
public int scrollValue {
get => scrollablePanel.scrollValue;
set => scrollablePanel.scrollValue = value;
}
public CustomScrollBar scrollBar {
get => scrollablePanel.scrollBar;
set => scrollablePanel.scrollBar = value;
}
public string Directory {
get => this._directory;
set {
if (System.IO.Directory.Exists(value)) {
this._directory = value;
GetDirectory();
}
}
}
public float ScrollSpeedMultiplier { get; set; }
public EventHandler OnDirectoryChanged = null;
public EventHandler<FileSelectedEventArgs> OnFileSelected = null;
public FileExplorer() {
InitializeComponent();
}
private void FileExplorer_Load(object sender, EventArgs e) {
AdjustSize();
}
private void FileExplorer_Resize(object sender, EventArgs e) {
AdjustSize();
}
private void AdjustSize() {
}
private void GetDirectory() {
scrollablePanel.Clear();
System.Diagnostics.Trace.WriteLine(this.Directory);
int offset = System.IO.Directory.GetParent(this.Directory) != null ? 1 : 0;
int colCount = scrollablePanel.Width / 145;
string[] dirs = System.IO.Directory.GetDirectories(new string(this.Directory.Where(c => !char.IsControl(c)).ToArray()));
Array.Sort(dirs);
if (offset == 1) {
DirectoryInfo parent = System.IO.Directory.GetParent(this.Directory);
scrollablePanel.Controls.Add(GetExplorerItem(parent.FullName, "..", new Point(0, 0)));
}
for (int i = 0; i < dirs.Length; i++)
scrollablePanel.Controls.Add(GetExplorerItem(dirs[i], new DirectoryInfo(dirs[i]).Name, new Point(((i + offset) % colCount) * 145, (i + offset) / colCount * 115 + 10)));
offset += dirs.Length;
dirs = System.IO.Directory.GetFiles(new string(this.Directory.Where(c => !char.IsControl(c)).ToArray()), "*.mp4", SearchOption.TopDirectoryOnly);
Array.Sort(dirs);
for (int i = 0; i < dirs.Length; i++)
scrollablePanel.Controls.Add(GetExplorerItem(dirs[i], new FileInfo(dirs[i]).Name, new Point(((i + offset) % colCount) * 145, (i + offset) / colCount * 115 + 10)));
System.Diagnostics.Trace.WriteLine(scrollablePanel.Count);
System.Diagnostics.Trace.WriteLine(scrollablePanel.VisibleControls);
this.Invalidate();
}
private Panel GetExplorerItem(string path, string text, Point location) {
BunifuImageButton bunifuImageButton = new BunifuImageButton();
Label label = new Label();
Panel panel = new Panel();
if (System.IO.Directory.Exists(path)) {
bunifuImageButton.Image = Properties.Resources.folder;
bunifuImageButton.Click += delegate (object sender, EventArgs e) {
this.Directory = path;
};
} else if (System.IO.File.Exists(path)) {
bunifuImageButton.Image = Properties.Resources.video_1;
}
bunifuImageButton.ImageActive = null;
bunifuImageButton.Location = new System.Drawing.Point(10, 0);
bunifuImageButton.Name = "bunifuImageButton";
bunifuImageButton.Size = new System.Drawing.Size(125, 70);
bunifuImageButton.SizeMode = System.Windows.Forms.PictureBoxSizeMode.Zoom;
bunifuImageButton.TabStop = false;
bunifuImageButton.Zoom = 5;
bunifuImageButton.Cursor = Cursors.Hand;
label.Font = new System.Drawing.Font("Century Gothic", 9.75F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, 0);
label.ForeColor = System.Drawing.Color.FromArgb(224, 224, 224);
label.Name = "label";
label.Dock = DockStyle.Bottom;
label.Size = new Size(145, 40);
label.Text = text;
label.TextAlign = ContentAlignment.MiddleCenter;
label.AutoEllipsis = true;
panel.Controls.Add(bunifuImageButton);
panel.Controls.Add(label);
panel.Location = location;
panel.Name = "panel";
panel.Size = new System.Drawing.Size(145, 110);
return panel;
}
private void textBoxUrl_KeyDown(object sender, KeyEventArgs e) {
if (e.KeyCode == Keys.Enter) {
this.Directory = this.textBoxUrl.Text;
this.textBoxUrl.Text = this.Directory;
}
}
}
public class FileSelectedEventArgs : EventArgs {
public FileInfo File { get; }
public FileSelectedEventArgs(string path) {
File = new FileInfo(path);
}
public FileSelectedEventArgs(FileInfo info) {
File = info;
}
}
}
The Scrollable panel contains an inner panel that gets moved up and down. The FileExplorer contains a textbox for the URL, a button, and a scrollable panel.
My problem is that when I run the application everything works fine. When I go to the parent folder (IMPORTANT, NOT A SUBDIR) and reenter the folder all controls that should be there are invisible, but they were added to the inner panel's control collection.
This is the only folder dir where this error occurs: D:\Serien\Anime\Yu-Gi-Oh! Zexal
Output of System.Diagnostics from FileExplorer.GetDirectory:
D:\Serien\Anime\Yu-Gi-Oh! Zexal
3
True
D:\Serien\Anime
47
True
D:\Serien\Anime\Yu-Gi-Oh! Zexal
3
True
Screenshot of app start:
Screenshot after reenter: