Warning once only: Detected a case where constraints ambiguously suggest a height of zero for a tableview cell's content view...

Warning once only: Detected a case where constraints ambiguously suggest a height of zero for a tableview cell's content view. We're considering the collapse unintentional and using standard height instead.

遇到以上错误, 添加以下代码可以解决:

self.tableView.rowHeight = 44.0f;