介绍
Masonry源码
在其官网上也进行了很多的介绍,在下面会写出我自己的一些见解.如果使用过iOS中系统的NSLayoutConstraints已经知道非常麻烦
如下代码就是系统的约束
UIView *superview = self; UIView *view1 = [[UIView alloc] init]; view1.translatesAutoresizingMaskIntoConstraints = NO; view1.backgroundColor = [UIColor greenColor]; [superview addSubview:view1]; UIEdgeInsets padding = UIEdgeInsetsMake(10, 10, 10, 10); [superview addConstraints:@[ //view1 constraints [NSLayoutConstraint constraintWithItem:view1 attribute:NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual toItem:superview attribute:NSLayoutAttributeTop multiplier:1.0 constant:padding.top], [NSLayoutConstraint constraintWithItem:view1 attribute:NSLayoutAttributeLeft relatedBy:NSLayoutRelationEqual toItem:superview attribute:NSLayoutAttributeLeft multiplier:1.0 constant:padding.left], [NSLayoutConstraint constraintWithItem:view1 attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:superview attribute:NSLayoutAttributeBottom multiplier:1.0 constant:-padding.bottom], [NSLayoutConstraint constraintWithItem:view1 attribute:NSLayoutAttributeRight relatedBy:NSLayoutRelationEqual toItem:superview attribute:NSLayoutAttributeRight multiplier:1 constant:-padding.right], ]];
安装
- 直接进入github进行源码下载
- 使用CocoaPod进行下载
使用
在上面介绍的时候我们看到系统要创建一个试图,距离上下左右都是10的这样一个约束需要写上很多代码,然而现在是使用Masonry的效果
UIEdgeInsets padding = UIEdgeInsetsMake(10, 10, 10, 10); [view1 mas_makeConstraints:^(MASConstraintMaker *make) { make.top.equalTo(superview.mas_top).with.offset(padding.top); //with is an optional semantic filler make.left.equalTo(superview.mas_left).with.offset(padding.left); make.bottom.equalTo(superview.mas_bottom).with.offset(-padding.bottom); make.right.equalTo(superview.mas_right).with.offset(-padding.right); }]; 甚至我们这样写得更加简洁
[view1 mas_makeConstraints:^(MASConstraintMaker *make) {
make.edges.equalTo(superview).with.insets(padding); }];接下来我们来观看下Masonry中的一些常用属性
// 左侧 @property (nonatomic, strong, readonly) MASConstraint *left; // 顶部 @property (nonatomic, strong, readonly) MASConstraint *top; // 右侧 @property (nonatomic, strong, readonly) MASConstraint *right; // 底部 @property (nonatomic, strong, readonly) MASConstraint *bottom; // 首部 @property (nonatomic, strong, readonly) MASConstraint *leading; // 尾部 @property (nonatomic, strong, readonly) MASConstraint *trailing; // 宽 @property (nonatomic, strong, readonly) MASConstraint *width; // 高 @property (nonatomic, strong, readonly) MASConstraint *height; // 中心点x @property (nonatomic, strong, readonly) MASConstraint *centerX; // 中心点y @property (nonatomic, strong, readonly) MASConstraint *centerY; // 文本基线 @property (nonatomic, strong, readonly) MASConstraint *baseline;
居中显示视图
UIView *myView = [[UIView alloc] init]; myView.backgroundColor = [UIColor blueColor]; [self.view addSubview:myView]; [myView mas_makeConstraints:^(MASConstraintMaker *make) { // 设置当前center和父视图的center一样 make.center.mas_equalTo(self.view); // 设置当前视图的大小 make.size.mas_equalTo(CGSizeMake(300, 300)); }];效果图
可以看到我们已经创建出一个位置居中,并且视图大小为300×300
设置视图并排
UIView *view1 = [[UIView alloc] init]; view1.backgroundColor = [UIColor redColor]; [myView addSubview:view1]; UIView *view2 = [[UIView alloc] init]; view2.backgroundColor = [UIColor yellowColor]; [myView addSubview:view2]; int padding = 10; [view1 mas_makeConstraints:^(MASConstraintMaker *make) { // 设置其位于父视图的Y的中心位置 make.centerY.mas_equalTo(myView.mas_centerY); // 设置其左侧和父视图偏移10个像素 make.left.equalTo(myView).with.offset(padding); // 设置其右侧和view2偏移10个像素 make.right.equalTo(view2.mas_left).with.offset(-padding); // 设置高度 make.height.mas_equalTo(@120); // 设置其宽度 make.width.equalTo(view2); }]; [view2 mas_makeConstraints:^(MASConstraintMaker *make) { make.centerY.mas_equalTo(myView.mas_centerY); make.left.equalTo(view1.mas_right).with.offset(padding); make.right.equalTo(myView).with.offset(-padding); make.height.mas_equalTo(view1); make.width.equalTo(view1); }];效果图:
提醒一下,以下代码等价
make.left.equalTo(myView).with.offset(padding); // 等价于 make.left.equalTo(myView.mas_left).with.offset(padding);也就是说默认情况下括号里面只写了视图的时候,其自动帮你添加当前masxxx(代表前面你需要设置的约束的位置).比如上面两行代码设置的make.left,当括号里面只写了myView的时候,会自动追加为myView.mas_left。
多个视图间隔相同
注意下面设置宽度的时候是传递的数组,这样才能让多个视图进行等距离显示
UIView *view1 = [[UIView alloc] init]; view1.backgroundColor = [UIColor redColor]; [myView addSubview:view1]; UIView *view2 = [[UIView alloc] init]; view2.backgroundColor = [UIColor yellowColor]; [myView addSubview:view2]; UIView *view3 = [[UIView alloc] init]; view3.backgroundColor = [UIColor greenColor]; [self.view addSubview:view3]; int padding = 10; [view1 mas_makeConstraints:^(MASConstraintMaker *make) { // 设置中心点 make.centerY.mas_equalTo(myView); // 设置左侧距离父视图10 make.left.equalTo(myView).with.offset(padding); // 设置右侧距离和view2的左侧相隔10 make.right.equalTo(view2.mas_left).with.offset(-padding); // 设置高度 make.height.mas_equalTo(@150); // 宽度设置和view2以及view3相同 make.width.equalTo(@[view2, view3]); }]; [view2 mas_makeConstraints:^(MASConstraintMaker *make) { make.centerY.mas_equalTo(myView); make.height.mas_equalTo(view1); make.width.equalTo(@[view1, view3]); }]; [view3 mas_makeConstraints:^(MASConstraintMaker *make) { make.centerY.mas_equalTo(myView); make.left.equalTo(view2.mas_right).with.offset(padding); make.right.equalTo(myView).with.offset(-padding); make.height.mas_equalTo(view1); make.width.equalTo(@[view2, view1]); }]; 效果图:
博主，给你合并下多个视图相隔相同的方法：
__weak typeof(self) weakSelf = self;
UIView * tempView = [[UIView alloc]init];
NSInteger count = 10;//设置一排view的个数
NSInteger margin = 10;//设置相隔距离
NSInteger height = 50;//设置view的高度
for (int i = 0; i < count; i ++) {
UIView * view = [[UIView alloc]init];
view.backgroundColor = [UIColor brownColor];
[self.view addSubview:view];
if (i == 0) {
[view mas_makeConstraints:^(MASConstraintMaker *make) {
make.left.equalTo(weakSelf.view).offset(margin);
make.centerY.equalTo(weakSelf.view);
make.height.mas_equalTo(height);
}];
}
else if (i == count – 1){
[view mas_makeConstraints:^(MASConstraintMaker *make) {
make.right.equalTo(weakSelf.view).offset(-margin);
make.left.equalTo(tempView.mas_right).offset(margin);
make.centerY.equalTo(tempView);
make.height.equalTo(tempView);
make.width.equalTo(tempView);
}];
}
else{
[view mas_makeConstraints:^(MASConstraintMaker *make) {
make.left.equalTo(tempView.mas_right).offset(margin);
make.centerY.equalTo(tempView);
make.height.equalTo(tempView);
make.width.equalTo(tempView);
}];
}
tempView = view;
[view layoutIfNeeded];
}