优化当传入参数为 null 时报错的问题

.gitignore

@@ -18,3 +18,4 @@ Thumbs.db
 .vscode
 .idea
 /docs/.vuepress/dist/
+package-lock.json

App.vue

@@ -23,7 +23,7 @@
         },
         data: function () {
             return {
-                val: ''
+                val: null
             }
         },
         methods: {

src/components/pro/pro.js

@@ -25,10 +25,9 @@ export default {
     },
     methods: {
         init() {// 初始化
-            this.currentValue = this.value;
             this.themeName = this.theme;
             this.preview = this.isPreview;
-            this.currentValue = this.value;
+            this.currentValue = this.value || '';
             if (this.isPreview) {
                 return;
             }

src/components/simple/simple.js

@@ -14,7 +14,7 @@ export default {
     },
     methods: {
         init() {
-            this.currentValue = this.value;
+            this.currentValue = this.value || '';
             this.themeName = this.theme;
             this.preview = this.isPreview;
             if (this.isPreview) {