As others pointed out, the standard way of doing this is to use UI Automation. Notepad++ does support UI Automation (to some extent, as it's somehow automatically provided by the UI Automation Windows layers).
Here is a sample C# console app that demonstrates the following sceanrio (you need to reference UIAutomationClient.dll, UIAutomationProvider.dll and UIAutomationTypes.dll):
1) get the first running notepad++ process (you must start at least one)
2) open two files (note there may be already other opened tabs in notepad++)
3) selects all tabs in an infinite loop
class Program
{
static void Main(string[] args)
{
// this presumes notepad++ has been started somehow
Process process = Process.GetProcessesByName("notepad++").FirstOrDefault();
if (process == null)
{
Console.WriteLine("Cannot find any notepad++ process.");
return;
}
AutomateNpp(process.MainWindowHandle);
}
static void AutomateNpp(IntPtr handle)
{
// get main window handle
AutomationElement window = AutomationElement.FromHandle(handle);
// display the title
Console.WriteLine("Title: " + window.Current.Name);
// open two arbitrary files (change this!)
OpenFile(window, @"d:my pathfile1.txt");
OpenFile(window, @"d:my pathfile2.txt");
// selects all tabs in sequence for demo purposes
// note the user can interact with n++ (for example close tabs) while all this is working
while (true)
{
var tabs = GetTabsNames(window);
if (tabs.Count == 0)
{
Console.WriteLine("notepad++ process seems to have gone.");
return;
}
for (int i = 0; i < tabs.Count; i++)
{
Console.WriteLine("Selecting tab:" + tabs[i]);
SelectTab(window, tabs[i]);
Thread.Sleep(1000);
}
}
}
static IList<string> GetTabsNames(AutomationElement window)
{
List<string> list = new List<string>();
// get tab bar
var tab = window.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.Tab));
if (tab != null)
{
foreach (var item in tab.FindAll(TreeScope.Children, PropertyCondition.TrueCondition).OfType<AutomationElement>())
{
list.Add(item.Current.Name);
}
}
return list;
}
static void SelectTab(AutomationElement window, string name)
{
// get tab bar
var tab = window.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.Tab));
// get tab
var item = tab.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.NameProperty, name));
if (item == null)
{
Console.WriteLine("Tab item '" + name + "' has been closed.");
return;
}
// select it
((SelectionItemPattern)item.GetCurrentPattern(SelectionItemPattern.Pattern)).Select();
}
static void OpenFile(AutomationElement window, string filePath)
{
// get menu bar
var menu = window.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.MenuBar));
// get the "file" menu
var fileMenu = menu.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.NameProperty, "File"));
// open it
SafeExpand(fileMenu);
// get the new File menu that appears (this is quite specific to n++)
var subFileMenu = fileMenu.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.Menu));
// get the "open" menu
var openMenu = subFileMenu.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.NameProperty, "Open..."));
// click it
((InvokePattern)openMenu.GetCurrentPattern(InvokePattern.Pattern)).Invoke();
// get the new Open dialog (from root)
var openDialog = WaitForDialog(window);
// get the combobox
var cb = openDialog.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.ComboBox));
// fill the filename
((ValuePattern)cb.GetCurrentPattern(ValuePattern.Pattern)).SetValue(filePath);
// get the open button
var openButton = openDialog.FindFirst(TreeScope.Children, new AndCondition(
new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.Button),
new PropertyCondition(AutomationElement.NameProperty, "Open")));
// press it
((InvokePattern)openButton.GetCurrentPattern(InvokePattern.Pattern)).Invoke();
}
static AutomationElement WaitForDialog(AutomationElement element)
{
// note: this should be improved for error checking (timeouts, etc.)
while(true)
{
var openDialog = element.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.Window));
if (openDialog != null)
return openDialog;
}
}
static void SafeExpand(AutomationElement element)
{
// for some reason, menus in np++ behave badly
while (true)
{
try
{
((ExpandCollapsePattern)element.GetCurrentPattern(ExpandCollapsePattern.Pattern)).Expand();
return;
}
catch
{
}
}
}
}
If you wonder how this has been made, then you must read about UI Automation. The mother of all tools is called Inspect: https://msdn.microsoft.com/library/windows/desktop/dd318521.aspx
Make sure you get version at least 7.2.0.0. Note there is another one called UISpy but inspect is better.
Note, unfortunately, notepad++ tab text content - because it's based on the custom scintilla editor control - does not properly supports automation (we can't read from it easily, I suppose we'd have to use scintilla Windows messages for this), but it could be added to it (hey, scintilla guys, if you read this ... :).