Protractor 如何在if条件下使用承诺

当条件满足时，我尝试按照代码行获取一个数值

this.getMessageThreadsPosition = function (k, sub, callback) {
      console.log(sub);
      for(var i = 1; i <= k; i++){


        commonsMethod.findElementDriver(that.messageSubjectTextPath(i)).then(function(foundelement){
                  foundelement.getText().then(function(text){
                      console.log(text);
                      if(text == sub){
                            callback(i);

                        }
                  });
              });
          }
      };

但如果情况不好，它似乎永远不会进去