be going to之后完全可以跟have to do结构，例如：

I think we are going to have to do better.我想我们将要做得更好。

I'm afraid we're going to have to bow out early.我担心我们不得不提前退场。

What are you going to have to drink?你要喝什么?

You're going to have to learn to give and take.你们必须学会互相迁就。

You're going to have to pull your socks up.你可得加把劲儿了。

You're just going to have to tough it out.你只好硬硬头皮撑到底了。

You're just going to have to have ice cream.你只好得吃冰淇淋了。

I'm going to have to push you for an answer.我将不得不催促你答复了。

We're going to have to postpone the meeting.我们必须将会议延后举行。

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但是，你说的那些句子中，will 可否换成 be going to 结构，首先要看这些句子中will换成be going to是否合适，因为will和be going to是有一定区别的。

be going to既可指主观打算也可指客观迹象表明将要发生。

will往往指没有经过计划而临时出现的意图，常伴有说话者的主观意识或将来必然发生的事。

I'm going to quit my present job. 我打算辞掉我现在的工作。（现在的打算，事先经过思考，指向将来）

The little boy is going to fall over.小男孩要摔倒了。（根据客观迹象判断）

I'll answer the door.我去开门。（未经事先考虑的意图）

I hope it will be fine tomorrow.我希望明天会晴天。（主观意愿）