ArcGIS Pro 3.4 API Reference Guide
ArcGIS.Desktop.Catalog Namespace / OpenItemDialog Class / ShowDialog Method
Example Version

ShowDialog Method (OpenItemDialog)
Displays the Browse dialog box to open or use selcted items.
Syntax
public override Nullable<bool> ShowDialog()

Return Value

A boolean indicating if the Browse dialog was dismissed by pressing OK or Cancel.
Remarks
You can either configure the Browse dialog box properties first then display it with the ShowDialog method, or display the dialog box and then set its properties.
Example
Show_OpenItemDialog
OpenItemDialog addToProjectDialog = new OpenItemDialog();
addToProjectDialog.Title = "Add To Project";
addToProjectDialog.InitialLocation = @"C:\Data\NewYork\Counties\Maps";
addToProjectDialog.MultiSelect = true;
addToProjectDialog.Filter = ItemFilters.Composite_Maps_Import;

bool? ok = addToMapDialog.ShowDialog();

if (ok == true)
{
  IEnumerable<Item> selectedItems = addToMapDialog.Items;
  foreach (Item selectedItem in selectedItems)
    MapFactory.Instance.CreateMapFromItem(selectedItem);
}
Geodatabase Content from Browse Dialog
var openDlg = new OpenItemDialog
{
  Title = "Select a Feature Class",
  InitialLocation = @"C:\Data",
  MultiSelect = false,
  BrowseFilter = BrowseProjectFilter.GetFilter(ArcGIS.Desktop.Catalog.ItemFilters.GeodatabaseItems_All)
};

//show the browse dialog
bool? ok = openDlg.ShowDialog();
if (!ok.HasValue || openDlg.Items.Count() == 0)
  return;   //nothing selected

await QueuedTask.Run(() =>
{
  // get the item
  var item = openDlg.Items.First();

  // see if the item has a dataset
  if (ItemFactory.Instance.CanGetDataset(item))
  {
    // get it
    using (var ds = ItemFactory.Instance.GetDataset(item))
    {
      // access some properties
      var name = ds.GetName();
      var path = ds.GetPath();

      // if it's a featureclass
      if (ds is ArcGIS.Core.Data.FeatureClass fc)
      {
        // create a layer 
        var featureLayerParams = new FeatureLayerCreationParams(fc)
        {
          MapMemberIndex = 0
        };
        var layer = LayerFactory.Instance.CreateLayer<FeatureLayer>(featureLayerParams, MapView.Active.Map);

        // continue
      }
    }
  }
});
Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.
See Also