fix when value is null
fix when value is null

Leopoldthecoder/element-1,Raganof/element,baiyaaaaa/element,baiyaaaaa/element,huguangju/element,immissile/m-element,huguangju/element,Raganof/element,JavascriptTips/element,immissile/m-element,Kingwl/element,Kingwl/element,ElemeFE/element,Leopoldthecoder/element-1,JavascriptTips/element,ElemeFE/element