Implement drop editor functions

Source/GrasscutterTools/Utils/UIUtil.cs

@@ -0,0 +1,23 @@
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace GrasscutterTools.Utils
+{
+    public static class UIUtil
+    {
+        /// <summary>
+        /// 播放按钮完成动画
+        /// </summary>
+        /// <param name="btn"></param>
+        /// <returns></returns>
+        public static async Task ButtonComplete(Button btn)
+        {
+            var t = btn.Text;
+            btn.Text = "√";
+            btn.Enabled = false;
+            await Task.Delay(300);
+            btn.Text = t;
+            btn.Enabled = true;
+        }
+    }
+}