使用Masonry对UIScrollView自动布局
之前使用Masonry对UIScrollView进行过约束,当时是遇到了问题的,怎么约束都不对,因为赶进度直接改用frame了也没有对问题深究。就这样过了很久.........,直到前一段换工作的时候面试官问到,使用Masonry对UIScrollView自动布局应该注意些什么?额....,犹豫了一段时间我只能搪塞说我一般都是用frame进行设置的,暂时没有遇到什么问题。虽然这么回答也没什么,但是感觉终归不是很好。出来混迟早是要还的!刚好最近公司不忙,想起了这个问题,那么就研究记录一下吧!
对UIScrollView的约束有很多方式,我只讲其中一种易懂、直观的方式
UIScrollView约束的关键是设置它的contentSize的大小,否则无法进行滚动显示。
给UIScrollView添加一个过渡视图containerView,这个containerView作为所有子控件的父视图,然后再设置containerView相对于UIScrollView的约束constraint和子控件相对于containerView的约束constraint。
最后再将最后一个子视图的右边距,或底边距设置成containerView的右边距,或底边距,以此来设置scrollView的contentSize在水平方向,或垂直方向的大小。
UIScrollView竖向滑动时,就把containerView的width固定
UIScrollView横向滑动时,就把containerView的height固定
如果看完上面的描述还没有明白,那直接看下面的代码,UIScrollView的约束其实都是一样的,记住即可
水平方向
UIScrollView *horizontalScrollView = [[UIScrollView alloc] init]; horizontalScrollView.backgroundColor = [UIColor orangeColor]; horizontalScrollView.pagingEnabled =YES; // 添加scrollView添加到父视图,并设置其约束 [self.view addSubview:horizontalScrollView]; [horizontalScrollView mas_makeConstraints:^(MASConstraintMaker *make) { make.top.and.left.mas_equalTo(10); make.right.mas_equalTo(-10); make.height.mas_equalTo(100); }]; // 创建过渡视图并设置contentSize和其约束 UIView *horizontalContainerView = [[UIView alloc] init]; [horizontalScrollView addSubview:horizontalContainerView]; [horizontalContainerView mas_makeConstraints:^(MASConstraintMaker *make) { make.edges.equalTo(horizontalScrollView); make.height.equalTo(horizontalScrollView);#//水平滚动高度固定,这个很重要 }]; //过渡视图上添加子视图 UIView *previousView =nil; for (int i =0; i <10; i++) { UILabel *label = [[UILabelalloc]init]; label.textAlignment =NSTextAlignmentCenter; label.backgroundColor = [UIColorcolorWithHue:(arc4random() %256 / 256.0) saturation:(arc4random() %128 /256.0) +0.5 brightness:(arc4random() %128 /256.0) +0.5 alpha:1]; label.text = [NSStringstringWithFormat:@"第 %d个视图", i]; //添加到过渡视图,并设置子视图的约束 [horizontalContainerView addSubview:label]; [label mas_makeConstraints:^(MASConstraintMaker *make) { make.top.and.bottom.equalTo(horizontalContainerView); make.width.equalTo(horizontalScrollView); if (previousView) { make.left.mas_equalTo(previousView.mas_right); } else { make.left.mas_equalTo(0); } }]; previousView = label; } #// 设置过渡视图的右距(此设置将影响到scrollView的contentSize)这个也是关键的一步 [horizontalContainerView mas_makeConstraints:^(MASConstraintMaker *make) { make.right.mas_equalTo(previousView.mas_right); }];
垂直平方向
UIScrollView *verticalScrollView = [[UIScrollView alloc] init]; verticalScrollView.backgroundColor = [UIColor greenColor]; verticalScrollView.pagingEnabled =YES; // 添加scrollView添加到父视图,并设置其约束 [self.view addSubview:verticalScrollView]; [verticalScrollView mas_makeConstraints:^(MASConstraintMaker *make) { make.left.mas_equalTo(10); make.bottom.and.right.mas_equalTo(-10.0); make.height.mas_equalTo(100); }]; // 设置scrollView的子视图,即过渡视图contentSize,并设置其约束 UIView *verticalContainerView = [[UIView alloc] init]; [verticalScrollView addSubview:verticalContainerView]; [verticalContainerView mas_makeConstraints:^(MASConstraintMaker *make) { make.top.left.bottom.and.right.equalTo(verticalScrollView); make.width.equalTo(verticalScrollView);#//垂直滚动宽度固定,这个很重要 }]; //过渡视图添加子视图 UIView *lastView =nil; for (NSInteger index =0; index <10; index++) { UILabel *label = [[UILabelalloc]init]; label.textAlignment =NSTextAlignmentCenter; label.backgroundColor = [UIColorcolorWithHue:(arc4random() %256 / 256.0) saturation:(arc4random() %128 /256.0) +0.5 brightness:(arc4random() %128 /256.0) +0.5 alpha:1]; label.text = [NSStringstringWithFormat:@"第 %ld个视图", index]; //添加到过渡视图,并设置子视图的约束 [verticalContainerView addSubview:label]; [label mas_makeConstraints:^(MASConstraintMaker *make) { make.left.and.right.equalTo(verticalContainerView); make.height.mas_equalTo(verticalScrollView.mas_height); if (lastView) { make.top.mas_equalTo(lastView.mas_bottom); } else { make.top.mas_equalTo(0); } }]; lastView = label; } #// 设置过渡视图的底边距(此设置将影响到scrollView的contentSize)这个也是关键的一步 [verticalContainerView mas_makeConstraints:^(MASConstraintMaker *make) { make.bottom.equalTo(lastView.mas_bottom); }];
xib对UIScrollerView的布局可以参考下面的文章
https://www.jianshu.com/p/1d3bb3cf7ee5
https://blog.csdn.net/dreams_deng/article/details/80523485