布局等宽高等间隔的一组view

masonry：
`
[self.view addSubview:self.redView];
[self.view addSubview:self.blueView];
[self.view addSubview:self.blackView];

CGFloat top = 80;
CGFloat padding = 20;
[self.redView mas_makeConstraints:^(MASConstraintMaker *make) {
    make.top.offset(top);
    make.left.offset(padding);
    make.height.mas_equalTo(self.redView.mas_width).multipliedBy(1);
}];

[self.blueView mas_makeConstraints:^(MASConstraintMaker *make) {
    make.top.mas_equalTo(self.redView);
    make.left.mas_equalTo(self.redView.mas_right).offset(padding);
    make.height.mas_equalTo(self.redView);
    make.width.mas_equalTo(self.redView);
}];

[self.blackView mas_makeConstraints:^(MASConstraintMaker *make) {
    make.top.mas_equalTo(self.blueView);
    make.left.mas_equalTo(self.blueView.mas_right).offset(padding);
    make.height.mas_equalTo(self.blueView);
    make.width.mas_equalTo(self.blueView);
    make.right.offset(-padding);
}];

[self.view layoutIfNeeded];
NSLog(@"%@\n%@\n%@",NSStringFromCGRect(self.redView.frame),NSStringFromCGRect(self.blueView.frame),NSStringFromCGRect(self.blackView.frame));

`
当padding = 20时：

屏幕快照 2019-12-09 上午11.00.18.png

当padding = 3时：

屏幕快照 2019-12-09 上午11.03.08.png

现象:当padding = 20时，views的宽度并不是严格相等，当padding=3时，views的宽度相等
结论：当屏幕宽度减去所有padding后，view的宽度如果可以均分则均分，如果不能，系统自动处理，且保留小数到.5

xib：同上