Masonry适配——（4）UIScrollView的设置

UISCrollView在使用时，如果作为父视图包含多个子视图时，我们需要设置它的contentSize的大小，否则无法进行滚动显示。使用frame进行设置时，只需要令xxxScrollView.contentSize = CGSizeMake(width,height)即可，且不管是水平方向，还是垂直方向都方便设置。

而当使用masonry时，应该怎么进行设置呢？因为使用masonry时，无法通过CGSizeMake进行设置它的contentSize，所以需要通过一个过渡视图进行处理。即scrollView作为父视图，添加子视图，即过渡视图A，然后再将其他真正需要添加到scrollView上的子视图a、b、c等添加到过渡视图A中，然后再将a、b、c等中的最后一个子视图的右边距，或底边距设置成过渡视图A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。

效果如下图所示（水平方向、垂直方向）





代码示例：

水平方向

UIScrollView *horizontalScrollView = [[UIScrollViewalloc]
init];

horizontalScrollView.backgroundColor = [UIColororangeColor];

horizontalScrollView.pagingEnabled =YES;

// 添加scrollView添加到父视图，并设置其约束

[self.viewaddSubview:horizontalScrollView];

[horizontalScrollView mas_makeConstraints:^(MASConstraintMaker *make) {

make.top.and.left.mas_equalTo(10);

make.right.mas_equalTo(-10);

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 *horizontalContainerView = [[UIViewalloc]
init];

[horizontalScrollView addSubview:horizontalContainerView];

[horizontalContainerView mas_makeConstraints:^(MASConstraintMaker *make) {

make.edges.equalTo(horizontalScrollView);

make.height.equalTo(horizontalScrollView);

}];

//
过渡视图添加子视图

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];

//
添加到父视图，并设置过渡视图中子视图的约束

[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）

[horizontalContainerView mas_makeConstraints:^(MASConstraintMaker *make) {

make.right.mas_equalTo(previousView.mas_right);

}];

垂直方向

UIScrollView *verticalScrollView = [[UIScrollViewalloc]
init];

verticalScrollView.backgroundColor = [UIColorgreenColor];

verticalScrollView.pagingEnabled =YES;

// 添加scrollView添加到父视图，并设置其约束

[self.viewaddSubview: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 = [[UIViewalloc]
init];

[verticalScrollView addSubview:verticalContainerView];

[verticalContainerView mas_makeConstraints:^(MASConstraintMaker *make) {

make.top.left.bottom.and.right.equalTo(verticalScrollView).with.insets(UIEdgeInsetsZero);

make.width.equalTo(verticalScrollView);

}];

//
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];

//
添加到父视图，并设置过渡视图中子视图的约束

[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）

[verticalContainerView mas_makeConstraints:^(MASConstraintMaker *make) {

make.bottom.equalTo(lastView.mas_bottom);

}];