我在WinForm里做了个代码，很管用
我拖动xml文件并放到tabPage。

private TextEditorControl AddNewTextEditor(string title)
        {
            var tab = new TabPage(title);
            var editor = new TextEditorControl();
            editor.Dock = System.Windows.Forms.DockStyle.Fill;
            editor.IsReadOnly = false;
            editor.Document.DocumentChanged += 
                new DocumentEventHandler((sender, e) => { SetModifiedFlag(editor, true); });
            // When a tab page gets the focus, move the focus to the editor control
            // instead when it gets the Enter (focus) event. I use BeginInvoke 
            // because changing the focus directly in the Enter handler doesn't 
            // work.
            tab.Enter +=
                new EventHandler((sender, e) => { 
                    var page = ((TabPage)sender);
                    page.BeginInvoke(new Action<TabPage>(p => p.Controls[0].Focus()), page);
                });
            tab.Controls.Add(editor);
            fileTabs.Controls.Add(tab);

            if (_editorSettings == null) {
                _editorSettings = editor.TextEditorProperties;
                OnSettingsChanged();
            } else
                editor.TextEditorProperties = _editorSettings;
            return editor;
        }

但是WPF有点脏。
我可以改变代码为WPF？？或其他方式..？谢谢你的帮助。