getElementById 取textarea 的值

let readCase = document.getElementById('readcase');
                                                if(res.message){
                                                    readCase.value = '';
                                                }else{
                                                    readCase.value = res.arr1;
                                                }

 

textarea的innerHTML和html獲取的是初始的值，如果值變化了仍然想要獲得值那麼就要使用value，value獲取的是實時的值