一、大家常见的用法是be disappointed in sb/sth，其实这里的in可以换成at、with、by、about、都是可以的，请看：
I'm disappointed in you─I really thought I could trust you!
你真让我失望——我原以为可以相信你的！
You should have accepted that. I'm disappointed in you.
你本应该接受那个的，我对你很失望。
Once again he was disappointed in love.
他又一次失恋了。
The boss was disappointed in the new hand's work.
老板对于新手的工作感到失望。
You must be pretty disappointed with/ at/ about/by your exam results.
你对你的考试成绩一定非常失望。
He was disappointed with his exclusion from the England squad.
他对自己没有入选英格兰队感到失望。
They were understandably disappointed with the result.
他们对结果感到失望是可以理解的。
I was very disappointed with myself.
我对自己感到非常失望。
We are utterly disappointed with you.
我们对你太失望了。
I was heart-broken and disappointed with Bill.
我对比尔痛心而失望。《亲历历史》
They were bitterly disappointed at the result of the game.
他们对比赛结果极为失望。
He was disappointed at not getting the job, but he'll get over it.
他没得到这份工作非常失望，不过他会想得开的。
I was much disappointed at his absence.
他不在，我感到很失望。
I was disappointed by the quality of the wine.
这酒的质量令我失望。
We're disappointed by these results but we're not downhearted.
我们对结果感到失望，但是并未丧失信心。
She was disappointed by his lack of initiative.
她对他缺少进取心感到失望。
A spokesman for UNHCR said he was surprised and disappointed by the decision.
联合国难民署的一位发言人说他对这一决定既震惊又失望。
To say we are disappointed about this is putting it mildly.
说我们对此很失望是很客气的说法。
We are much disappointed about the weather.
这天气叫我们很扫兴。
be disappointed in sb/sth，其实这里的in可以换成at、with、by、about外，也可以换成for, over,of
She's disappointed for him.她对他很失望。
He's disappointed of his ambition. 他对自己的抱负感到失望。（他因实现不了抱负而感到失望。）
He's disappointed of the car.
他因等不到停车位而感到失望。
He's disappointed over the criticism that his speech had aroused.
他对演讲引起的批评感到失望。
be disappointing for sb对于某人……时令人失望的，这个主语是令人失望的
The outcome of the court case was disappointing for the family involved.
诉讼案的结果使得涉及本案的这家人非常失望。
二、be disappointed to do
He was disappointed to see she wasn't at the party.
看到她没来参加晚会，他感到很失望。
She was disappointed not to be chosen.
她没有被选中感到很沮丧。
I was disappointed to find that they had left already.
我发现他们已经离开了，觉得很失望。
She was disappointed not to be accepted into the club.
她没有获准加入俱乐部，感到失望。
I was disappointed to miss Bryan, who had just checked out
我非常失望没有见着布赖恩，他刚退房走了。
I was completely disappointed to hear that.
听到那个消息后我彻底失望了。
三、be disappointed+ that 从句
I'm disappointed (that) it was sold out.
全都卖完了，我感到很失望。
I was disappointed that Kluge was not there
克卢格不在那儿，我很失望。
I was disappointed that he was unable to come.
他不能来令我感到很失望。
I feel very disappointed that you are unable to support me on this project.
我很失望，你们不能在这个项目上支持我。
I was disappointed that I hadn't died for my country.
我因为没有为祖国战死而感到遗憾。
On the day of the competition, Cassie was disappointed that her beans were in last place.
比赛当天,卡西对自己的豆子排在最后一名感到失望。
She was disappointed that he never replied to her letter.
他从来不回她的信，她感到很失望。
有时候从句用虚拟语气表示：竟然（表示一种很意外、很失望的语气）
I’m rather disappointed that he should the post.
他竟然会得到那个职位，我感到很失望。
He is disappointed that he shouldn't be chosen this time.
他很失望，这次他竟然没有被选上。
She was disappointed that he should have failed her in that way.
他竟会那样辜负她，她很失望。
四、disappoint 动词，使失望;使破灭;使落空
disappoint+宾语，使……失望
Her decision to cancel the concert is bound to disappoint her fans.
她决定取消这场音乐会，肯定会使她的歌迷失望。
The movie had disappointed her
这部电影使她失望。
She knew that she would disappoint him.
她知道她会令他失望的。
He had a long memory for people who had disappointed him.
谁让他失望，他总是记恨在心。
The new government had soon disappointed the hopes of many of its supporters.
新政府不久便使许多支持者的希望破灭了。
五、注意不要混淆 disappointed 和 disappointing。
a disappointing result/performance
令人失望的结果 / 演出
The disappointing sales figures foreshadow more redundancies
令人失望的销售额预示着会有更多人被裁员。
disappointing所修饰的中心词本身就是有令人失望的性质或品质、特征、性质。
The girl was very disappointing. 这女孩很令人失望。
In summary, this was a disappointing performance.
总的来说，这场演出令人失望。
The play was built up to be a masterpiece but I found it very disappointing.
那部戏被捧为杰作，可我却大失所望。
The debate was a pretty disappointing affair.
那次辩论使人颇感失望。
The wine was excellent, but the food was disappointing
酒棒极了，但是饭菜却让人不敢恭维。
The recession is largely blamed for the disappointing response to the appeal.
对此呼吁的反应令人失望，主要归咎于经济衰退。
His score on the reading test was very disappointing.
他阅读测验的成绩很令人失望。
Our holiday was so disappointing.
假期真让人败兴。
Lunch tended to be an even more disappointing affair.
午餐往往是一件更令人失望的事情。
How disappointing!
真叫人扫兴！
disappointed表示人对……感到失望
be disappointed with/in/at/ by/about
可以单独做状语：
Disappointed she returned to her hometown.
她失望地回到家乡。
He turned away disappointed.
他失望地走了。
注意事项：如果用于修饰 voice, look, expression, appearance, manner等名词，则表示与之相关名词的逻辑主语感到失望。
We noticed a disappointing look on his face. 我们注意到他脸上一种令人失望的表情。
例句解析：“他”并不失望，但见了他表情的人会失望。
We noticed a disappointed look on his face. 我们注意到他脸上有一种失望的表情。
例句解析：感到失望的是“他”，不是别人。
A disappointed look came into his face.
他脸上浮现出一种失望的神情。
She had a very disappointed look when I said she must stay at home.
当我说她必须留在家的时候，她显得很扫兴