优化页打开逻辑

VIZ.Package.Module/ControlObject/FieldTree/ViewModel/FieldTreeViewModel.cs

@@ -41,6 +41,7 @@ namespace VIZ.Package.Module
         /// </summary>
         private void InitMessage()
         {
+            ApplicationDomainEx.MessageManager.Register<PageOpenMessage>(this, this.OnPageOpenMessage);
             ApplicationDomainEx.MessageManager.Register<PageInitedMessage>(this, this.OnPageInitedMessage);
             ApplicationDomainEx.MessageManager.Register<ProjectCloseMessage>(this, this.OnProjectCloseMessage);
         }
@@ -128,6 +129,15 @@ namespace VIZ.Package.Module
         // =============================================================
 
         /// <summary>
+        /// 打开页命令
+        /// </summary>
+        /// <param name="msg">消息</param>
+        private void OnPageOpenMessage(PageOpenMessage msg)
+        {
+            this.IsLoading = true;
+        }
+
+        /// <summary>
         /// 页初始化完成消息
         /// </summary>
         /// <param name="msg">消息</param>