初始化（包含登录模块）

wxcomponents/vant/mixins/observer/behavior.js

@@ -0,0 +1,14 @@
+export const behavior = Behavior({
+    methods: {
+        set(data, callback) {
+            return new Promise(resolve => {
+                this.setData(data, () => {
+                    if (callback && typeof callback === 'function') {
+                        callback.call(this);
+                    }
+                    resolve();
+                });
+            });
+        }
+    }
+});