提交用户部分代码

Source/Store.Management.Framework/Controls/ViewModelBase.cs

@@ -5,6 +5,20 @@ namespace Store.Management.Framework.Controls;
 
 public abstract class ViewModelBase : BindableBase
 {
+    private bool hasLoaded;
+
+    internal void NotifyLoaded()
+    {
+        if (!hasLoaded)
+        {
+            hasLoaded = true;
+            OnLoadedOnce();
+        }
+        OnLoaded();
+    }
+
+    /// <summary>当前实例首次加载时调用，先于 OnLoaded。</summary>
+    protected virtual void OnLoadedOnce() { }
     protected internal virtual void OnLoaded() { }
     protected internal virtual void OnUnloaded() { }
     protected internal virtual void OnActivated() { }