优化index.vue.vm模板，!=1修改为严格不等；undefined修改为null

ruoyi-generator/src/main/resources/vm/vue/index.vue.vm

@@ -286,7 +286,7 @@ export default {
         pageSize: 10,
 #foreach ($column in $columns)
 #if($column.query)
-        $column.javaField: undefined#if($velocityCount != $columns.size()),#end
+        $column.javaField: null#if($velocityCount != $columns.size()),#end
 
 #end
 #end
@@ -363,7 +363,7 @@ export default {
         $column.javaField: []#if($velocityCount != $columns.size()),#end
 
 #else
-        $column.javaField: undefined#if($velocityCount != $columns.size()),#end
+        $column.javaField: null#if($velocityCount != $columns.size()),#end
 
 #end
 #end
@@ -383,7 +383,7 @@ export default {
     // 多选框选中数据
     handleSelectionChange(selection) {
       this.ids = selection.map(item => item.${pkColumn.javaField})
-      this.single = selection.length!=1
+      this.single = selection.length!==1
       this.multiple = !selection.length
     },
     /** 新增按钮操作 */
@@ -408,7 +408,7 @@ export default {
       });
     },
     /** 提交按钮 */
-    submitForm: function() {
+    submitForm() {
       this.#[[$]]#refs["form"].validate(valid => {
         if (valid) {
 #foreach ($column in $columns)
@@ -416,7 +416,7 @@ export default {
           this.form.$column.javaField = this.form.${column.javaField}.join(",");
 #end
 #end
-          if (this.form.${pkColumn.javaField} != undefined) {
+          if (this.form.${pkColumn.javaField} != null) {
             update${BusinessName}(this.form).then(response => {
               if (response.code === 200) {
                 this.msgSuccess("修改成功");
@@ -465,4 +465,4 @@ export default {
     }
   }
 };
-</script>
\ No newline at end of file
+</script>