OpenFileDialog Component Overview (Windows Forms)
Use this component within your Windows-based application as a simple solution for file selection in lieu of configuring your own dialog box. By relying on standard Windows dialog boxes, you create applications whose basic functionality is immediately familiar to users. Be aware, however, that when using the OpenFileDialog component, you must write your own file-opening logic.
Use the ShowDialog method to display the dialog at run time. You can enable users to multi-select files to be opened with the Multiselect property. Additionally, you can use the ShowReadOnly property to determine if a read-only check box appears in the dialog box. The ReadOnlyChecked property indicates whether the read-only check box is selected. Finally, the Filter property sets the current file name filter string, which determines the choices that appear in the "Files of type" box in the dialog box.
When it is added to a form, the OpenFileDialog component appears in the tray at the bottom of the Windows Forms Designer.