Angular.JS利用ng-disabled属性和ng-model实现禁用button效果

<div>  <div>   <textarea name="" id="" rows="3" class="form-control" ng-model="shyj" placeholder="在此输入审批意见"></textarea>  </div>  <div>   <div>    <button class="btn btn-sm btn-block btn-primary" ng-disabled="!shyj"     ng-click="agreeClick(SM.YGBH,SM.RQ,shyj);" ng-tap="$navigate.go('/home')">    提交    </button>   </div>  </div> </div> 

$scope.agreeClick=function(v_shyg,v_rq,shyj){//审核通过  $scope.v_shzt=0;  $scope.v_shyg=v_shyg;  $scope.v_rq=v_rq;  $scope.shyj=shyj;  $scope.v_lsh=0;  /*if(!$scope.shyj||$scope.shyj==''){   myTip("审核意见不能为空");   return false;  }*/  HomeService.agreeClick({YGBH:$scope.YGBH,v_rq:$scope.v_rq,v_shzt:$scope.v_shzt,v_shyg:$scope.v_shyg,v_shyj:$scope.shyj,v_lsh:$scope.v_lsh}).then(function(data){   var info=data.msg;   if (info[0].code === "0") {//查询到结果   myTip("审核成功");    $navigate.go("/LogList");   }else{    myTip("审核失败:"+info[0].msg);   } //  console.log("desk: %o", data); //  $scope.LogList=data.answers[0]; //  $scope.abc=data.answers[0][0].YGBH; //  console.log("bb: %o",$scope.abc);    }); }