export DateSelector, fix issue about column.align and filter panel position of the last header cell.

lib/ui/dropdown.js

@@ -560,7 +560,7 @@ export class Dropdown {
         }
     }
 
-    static resolve(dom = document.body) {
+    static resolve(dom = document.body, trigger) {
         const selects = dom.querySelectorAll('select');
         for (let sel of selects) {
             const source = [...sel.children].map(it => {
@@ -572,6 +572,9 @@ export class Dropdown {
                 tabIndex: sel.tabIndex
             });
             drop.source = source;
+            if (typeof trigger === 'function') {
+                drop.onSelected = item => trigger.call(drop, item);
+            }
             sel.parentElement.replaceChild(drop.create(), sel);
         }
         return dom;