1 先从问题说起：将masonry封装进了sdk后，在其他程序中调用即崩溃，报unrecognized selector sent to instance错误
查了很久，在stockoverflow上找到解决方法：是调用sdk的时候没有在flag中加入-Objc 和-all_load
Make sure you have linked the Masonry static library successfully if you didn't use cocoapods, besides, Masonry mainly expands some objective-c categories for UIKit/AppKit, so you had better check the following links out. Briefly, you should add flag -ObjC and -all_load to your project's "Other linker flags".
如图位置：
2 在使用masonry的时候注意几个方法几个参数就可以了
1 left/right/top/bottom/leading/trailing/width/height/centerX/centerY/baseline
几个参数都很好理解,left/right与leading/trailing意义相同，部分使用情况不同（暂时没用到），可以直接食用leading/trailing
2 - (NSArray*)MAS_makeConstraints:(void(^)(MASConstraintMaker*make))block;
添加约束
- (NSArray*)MAS_updateConstraints:(void(^)(MASConstraintMaker*make))block;
更新约束
- (NSArray*)MAS_remakeConstraints:(void(^)(MASConstraintMaker*make))block;
删除原来的所有约束
3 具体使用，1个例子就明白了
[self.button1 MAS_makeConstraints:^(MASConstraintMaker*make) {
make.centerX.equalTo(self.view);//横向中点父类
make.top.equalTo(self.view).with.offset(kScreenHeight/2-35);
make.size.MAS_equalTo(CGSizeMake(150,50));
}];
