ArcGIS Pro 修改一个图片element

IEnumerable<LayoutProjectItem> layouts = Project.Current.GetItems<LayoutProjectItem>();
            foreach (LayoutProjectItem layoutItem in layouts)
                if (layoutItem != null)
                {
                    await QueuedTask.Run(() =>
                    {
                        Layout layout = layoutItem.GetLayout();
                        if (layout != null)
                        {
                            if (layout.FindElement("Client Logo") is PictureElement picElm)
                            {
                                if (Equals(Module1.LayoutLogo, picElm.SourcePath.ToString()))
                                {
                                }
                                else
                                {
                                    try
                                    {
                                        if (Module1.LayoutLogo != null)
                                        {
                                            picElm.SetSourcePath($@"{Module1.LayoutLogo}");
                                            var lyt_cim = layout.GetDefinition();
                                            layout.SetDefinition(lyt_cim);
                                        }
                                    }
                                    catch (Exception)
                                    {
                                        ArcGIS.Desktop.Framework.Dialogs.MessageBox.Show("Incorrect Client Logo File Path", "Failure", System.Windows.MessageBoxButton.OK, System.Windows.MessageBoxImage.Warning);
                                    }
                                }
                            }
                        }
                    });
                }