iOS-systemLayoutSizeFittingSize获取布局后控件的的高度
[self addSubview:self.evaluateTitleLbl];
[_evaluateTitleLbl mas_makeConstraints:^(MASConstraintMaker *make) {
make.left.equalTo(_evaluateTitle.mas_left);
make.top.equalTo(_evaluateTitle.mas_bottom).offset(12);
make.right.equalTo(self.mas_right).offset(-15);
}];
CGfloat height =[self.evaluateTitleLbl systemLayoutSizeFittingSize:UILayoutFittingCompressedSize].height;
这里的height 就是获取布局后的 label 实际高度。
