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项目介绍：
-
瀑布流（OC和Swift）
算封装的比较好。提供接口，只需要成为MGWaterFlayout的代理，即可在外界设置那个cell的间距，collection View 的inset等进行UI界面的布局，非常方便。
效果
github网址：
OC源码查看
Swift源码项目查看
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OC
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.h
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// MGWaterflowLayout.h
// MGPuBuLiuDemo
// Created by ming on 16/6/9.
// Copyright © 2016年 ming. All rights reserved.
#import <UIKit/UIKit.h>
@class MGWaterflowLayout;
#pragma mark - 协议
@protocol MGWaterflowLayoutDelegate <NSObject>
@optional
- (CGFloat)waterflowLayout:(MGWaterflowLayout *)waterflowLayout heightForItemAtIndex:(NSIndexPath *)indexPath itemWidth:(CGFloat)itemWidth;
@optional
- (CGFloat)columnCountInWaterflowLayout:(MGWaterflowLayout *)waterflowLayout;
- (CGFloat)columnMarginInWaterflowLayout:(MGWaterflowLayout *)waterflowLayout;
- (CGFloat)rowMarginInWaterflowLayout:(MGWaterflowLayout *)waterflowLayout;
- (UIEdgeInsets)edgeInsetsInWaterflowLayout:(MGWaterflowLayout *)waterflowLayout;
- (CGSize)layoutCollectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)layout
sizeForItemAtIndexPath:(NSIndexPath *)indexPath;
@end
#pragma mark - MGWaterflowLayout
@interface MGWaterflowLayout : UICollectionViewFlowLayout
/** 代理 */
@property (nonatomic, weak) id<MGWaterflowLayoutDelegate> delegate;
@end-
.m
// MGWaterflowLayout.m
// MGPuBuLiuDemo
// Created by ming on 16/6/9.
// Copyright © 2016年 ming. All rights reserved.
#import "MGWaterflowLayout.h"
/** 默认的列数 */
static const NSInteger MGDefaultColumnCount = 3;
/** 每一列之间的间距 */
static const CGFloat MGDefaultColumnMargin = 10;
/** 每一行之间的间距 */
static const CGFloat MGDefaultRowMargin = 10;
/** 边缘间距 */
static const UIEdgeInsets MGDefaultEdgeInsets = {10, 10, 10, 10};
@interface MGWaterflowLayout ()
/** 存放所有cell的布局属性 */
@property (nonatomic, strong) NSMutableArray *attrsArray;
/** 存放所有列的当前高度 */
@property (nonatomic, strong) NSMutableArray *columnHeights;
/** 每一行之间的间距 */
- (CGFloat)rowMargin;
/** 每一列之间的间距 */
- (CGFloat)columnMargin;
/** 列数 */
- (NSInteger)columnCount;
/** 边缘间距 */
- (UIEdgeInsets)edgeInsets;
@end
@implementation MGWaterflowLayout
#pragma mark - 常见数据处理
- (CGFloat)rowMargin
{
if ([self.delegate respondsToSelector:@selector(rowMarginInWaterflowLayout:)]) {
return [self.delegate rowMarginInWaterflowLayout:self];
} else {
return MGDefaultRowMargin;
}
}
- (CGFloat)columnMargin
{
if ([self.delegate respondsToSelector:@selector(columnMarginInWaterflowLayout:)]) {
return [self.delegate columnMarginInWaterflowLayout:self];
} else {
return MGDefaultColumnMargin;
}
}
- (NSInteger)columnCount
{
if ([self.delegate respondsToSelector:@selector(columnCountInWaterflowLayout:)]) {
return [self.delegate columnCountInWaterflowLayout:self];
} else {
return MGDefaultColumnCount;
}
}
- (UIEdgeInsets)edgeInsets
{
if ([self.delegate respondsToSelector:@selector(edgeInsetsInWaterflowLayout:)]) {
return [self.delegate edgeInsetsInWaterflowLayout:self];
} else {
return MGDefaultEdgeInsets;
}
}
#pragma mark - 懒加载
- (NSMutableArray *)columnHeights
{
if (!_columnHeights) {
_columnHeights = [NSMutableArray array];
}
return _columnHeights;
}
- (NSMutableArray *)attrsArray
{
if (!_attrsArray) {
_attrsArray = [NSMutableArray array];
}
return _attrsArray;
}
- (void)prepareLayout{
[super prepareLayout];
#warning 删除以前保存的高度
[self.columnHeights removeAllObjects];
for (NSInteger i = 0; i < self.columnCount; i++) {
[self.columnHeights addObject:@(self.edgeInsets.top)];
}
// 清除之前所有的布局属性
[self.attrsArray removeAllObjects];
// 1.获取cell的个数
NSInteger count = [self.collectionView numberOfItemsInSection:0];
// 清除之前所有的布局属性
[self.attrsArray removeAllObjects];
// 2.遍历cell，把每一个布局添加到数组
for (NSInteger i = 0; i < count; i++) {
// 创建位置
NSIndexPath *indexPath = [NSIndexPath indexPathForItem:i inSection:0];
// 获取indexPath位置cell对应的布局属性
UICollectionViewLayoutAttributes *attrs = [self layoutAttributesForItemAtIndexPath:indexPath];
[self.attrsArray addObject:attrs];
}
}
- (UICollectionViewLayoutAttributes *)layoutAttributesForItemAtIndexPath:(NSIndexPath *)indexPath{
// 创建布局属性
UICollectionViewLayoutAttributes *attrs = [UICollectionViewLayoutAttributes layoutAttributesForCellWithIndexPath:indexPath];
CGFloat x,y,w,h;
// w = (self.collectionView.frame.size.width - [self edgeInsets].left - [self edgeInsets].right - ([self columnCount] - 1) * MGDefaultColumnMargin)/[self columnCount];
w = (self.collectionView.frame.size.width - self.edgeInsets.left - self.edgeInsets.right - (self.columnCount - 1) * self.columnMargin) / self.columnCount;
// 通过代理可以设置高度
if ([self.delegate respondsToSelector:@selector(waterflowLayout:heightForItemAtIndex:itemWidth:)]) {
h = [self.delegate waterflowLayout:self heightForItemAtIndex:indexPath itemWidth:w];
}else{
h = 70 + arc4random_uniform(100);
}
// 取得所有列中高度最短的列
NSInteger minHeightColumn = [self minHeightColumn];
// x = MGDefaultEdgeInsets.left + minHeightColumn * (w + MGDefaultColumnMargin);
x = self.edgeInsets.left + minHeightColumn * (w + self.columnMargin);
y = self.edgeInsets.top + [self.columnHeights[minHeightColumn] floatValue] + self.rowMargin;
#warning 更改最短的一列
[self.columnHeights replaceObjectAtIndex:minHeightColumn withObject:@(y+h)];
attrs.frame = CGRectMake(x, y, w, h);
return attrs;
}
/**
* 决定cell的排布
* 第一次显示时会调用一次
* 用力拖拽时也会调一次
*/
- (NSArray<UICollectionViewLayoutAttributes *> *)layoutAttributesForElementsInRect:(CGRect)rect{
return self.attrsArray;
}
/// 返回collectionView的滚动范围
- (CGSize)collectionViewContentSize{
if (self.columnHeights.count == 0) {
return CGSizeMake(0, 0);
}
// 获得最高的列
NSInteger maxColum = [self maxHeightColumn];
CGFloat height = [self.columnHeights[maxColum] floatValue] + MGDefaultEdgeInsets.bottom;
CGFloat width = self.collectionView.frame.size.width;
return CGSizeMake(width, height);
}
/// 取得所有列中高度最短的列
- (NSInteger)minHeightColumn{
// 找出columnHeights的最小值
NSInteger minHeightColum = 0;
CGFloat minColumHeight = [self.columnHeights[0] floatValue];
for (NSInteger i = 1; i < self.columnHeights.count; i++) {
CGFloat tempHeight = [self.columnHeights[i] floatValue];
if (tempHeight < minColumHeight) {
minHeightColum = i;
minColumHeight = tempHeight;
}
}
return minHeightColum;
}
/// 取得所有列中高度最高的列
- (NSInteger)maxHeightColumn{
// 找出columnHeights的最小值
NSInteger maxHeightColumn = 0;
CGFloat maxColumnHeight = [self.columnHeights[0] floatValue];
for (NSInteger i = 1; i < self.columnHeights.count; i++) {
CGFloat tempHeight = [self.columnHeights[i] floatValue];
if (tempHeight > maxColumnHeight) {
maxHeightColumn = i;
maxColumnHeight = tempHeight;
}
}
return maxHeightColumn;
}
///**
// * 在元素的Interactive Movement期间被调用
// * 它带有target（目标元素）和先前的cell的indexPaths（索引地址）
// */
//- (UICollectionViewLayoutInvalidationContext *)invalidationContextForInteractivelyMovingItems:(NSArray<NSIndexPath *> *)targetIndexPaths withTargetPosition:(CGPoint)targetPosition previousIndexPaths:(NSArray<NSIndexPath *> *)previousIndexPaths previousPosition:(CGPoint)previousPosition{
// UICollectionViewLayoutInvalidationContext *context = [super invalidationContextForInteractivelyMovingItems:targetIndexPaths withTargetPosition:targetPosition previousIndexPaths:previousIndexPaths previousPosition:previousPosition];
// [self.collectionView moveItemAtIndexPath:previousIndexPaths[0] toIndexPath:targetIndexPaths[0]];
//
// [self.collectionView reloadData];
// return context;
//}
//
///**
// * 这个与上一个函数类似，但它只在Interactive Movement结束后才调用
// * 它带有target（目标元素）和先前的cell的indexPaths（索引地址）
// */
//- (UICollectionViewLayoutInvalidationContext *)invalidationContextForEndingInteractiveMovementOfItemsToFinalIndexPaths:(NSArray<NSIndexPath *> *)indexPaths previousIndexPaths:(NSArray<NSIndexPath *> *)previousIndexPaths movementCancelled:(BOOL)movementCancelled{
// UICollectionViewLayoutInvalidationContext *context = [super invalidationContextForEndingInteractiveMovementOfItemsToFinalIndexPaths:indexPaths previousIndexPaths:previousIndexPaths movementCancelled:movementCancelled];
// [self.collectionView moveItemAtIndexPath:previousIndexPaths[0] toIndexPath:indexPaths[0]];
// return context;
//}
@end-
Swift
// MGWaterFlowLayout.swift
// MGDS_Swift
// Created by i-Techsys.com on 17/1/21.
// Copyright © 2017年 i-Techsys. All rights reserved.
import UIKit
// MARK: - 协议
@objc
protocol MGWaterFlowLayoutDelegate: NSObjectProtocol {
@objc optional func waterflowLayout(waterflowLayout: MGWaterFlowLayout,heightForItemAtIndex indexPath: IndexPath,itemWidth: CGFloat) -> CGFloat
@objc optional func columnCountInWaterflowLayout(waterflowLayout: MGWaterFlowLayout) -> Int
@objc optional func columnMarginInWaterflowLayout(waterflowLayout: MGWaterFlowLayout) -> CGFloat
@objc optional func rowMarginInWaterflowLayout(waterflowLayout: MGWaterFlowLayout) -> CGFloat
@objc optional func edgeInsetsInWaterflowLayout(waterflowLayout: MGWaterFlowLayout) -> UIEdgeInsets
@objc optional func layoutCollectionView(collectionView: UICollectionView,layout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: IndexPath)
}
// MARK: - 默认参数
/** 默认的列数 */
private let MGDefaultColumnCount: Int = 3
/** 每一列之间的间距 */
private let MGDefaultColumnMargin: CGFloat = 10
/** 每一行之间的间距 */
private let MGDefaultRowMargin: CGFloat = 10
/** 边缘间距 */
private let MGDefaultEdgeInsets: UIEdgeInsets = UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10)
class MGWaterFlowLayout: UICollectionViewFlowLayout {
// MARK: - 自定义属性
/** 存放所有cell的布局属性 */
fileprivate var attrsArray = [UICollectionViewLayoutAttributes]()
/** 存放所有列的当前高度 */
fileprivate var columnHeights: [CGFloat] = [CGFloat]()
/** MGWaterFlowLayout的代理 */
weak var delegate: MGWaterFlowLayoutDelegate?
}
// MARK: - 边距和距离等
extension MGWaterFlowLayout {
func rowMargin() -> CGFloat {
if (self.delegate?.responds(to: #selector(MGWaterFlowLayoutDelegate.rowMarginInWaterflowLayout(waterflowLayout:))))! {
return (delegate?.rowMarginInWaterflowLayout!(waterflowLayout: self))!
}else {
return MGDefaultRowMargin
}
}
func columnMargin() -> CGFloat {
if (self.delegate?.responds(to: #selector(MGWaterFlowLayoutDelegate.columnMarginInWaterflowLayout(waterflowLayout:))))! {
return (delegate?.columnMarginInWaterflowLayout!(waterflowLayout: self))!
}else {
return MGDefaultColumnMargin
}
}
func columnCount() -> Int {
if (self.delegate?.responds(to: #selector(MGWaterFlowLayoutDelegate.columnCountInWaterflowLayout(waterflowLayout:))))! {
return (delegate?.columnCountInWaterflowLayout!(waterflowLayout: self))!
}else {
return MGDefaultColumnCount
}
}
func edgeInsets() -> UIEdgeInsets {
if (self.delegate?.responds(to: #selector(MGWaterFlowLayoutDelegate.edgeInsetsInWaterflowLayout(waterflowLayout:))))! {
return (delegate?.edgeInsetsInWaterflowLayout!(waterflowLayout: self))!
}else {
return MGDefaultEdgeInsets
}
}
}
// MARK: - 系统方法
extension MGWaterFlowLayout {
override func prepare() {
super.prepare()
columnHeights.removeAll()
for _ in 0..<self.columnCount() {
self.columnHeights.append(self.edgeInsets().top)
}
// 清除之前所有的布局属性
attrsArray.removeAll()
// 1.获取cell的个数
let count = (collectionView?.numberOfItems(inSection: 0))! as Int
// 2.遍历cell，把每一个布局添加到数组
for i in 0..<count {
let indexPath = IndexPath(item: i, section: 0)
let attrs = self.layoutAttributesForItem(at: indexPath)
attrsArray.append(attrs!)
}
}
override func layoutAttributesForItem(at indexPath: IndexPath) -> UICollectionViewLayoutAttributes? {
super.layoutAttributesForItem(at: indexPath)
// 创建布局属性
let attrs = UICollectionViewLayoutAttributes(forCellWith: indexPath)
var x,y,w,h :CGFloat
w = (self.collectionView!.frame.size.width - self.edgeInsets().left - self.edgeInsets().right - (CGFloat(self.columnCount()-1) * self.columnMargin())) / CGFloat(self.columnCount())
// 通过代理可以设置高度
if (self.delegate?.responds(to: #selector(MGWaterFlowLayoutDelegate.waterflowLayout(waterflowLayout:heightForItemAtIndex:itemWidth:))))! {
h = self.delegate!.waterflowLayout!(waterflowLayout: self, heightForItemAtIndex: indexPath, itemWidth: w)
}else {
h = CGFloat(70) + CGFloat(arc4random_uniform(100))
}
// 取得所有列中高度最短的列
let minHeightColumn = self.minHeightColumn()
x = self.edgeInsets().left + CGFloat(minHeightColumn) * (w + self.columnMargin());
y = self.edgeInsets().top + self.columnHeights[minHeightColumn] + self.rowMargin()
// #warning 更改最短的一列
self.columnHeights[minHeightColumn] = y + h
attrs.frame = CGRect(x: x, y: y, width: w, height: h)
return attrs;
}
/**
* 决定cell的排布
* 第一次显示时会调用一次
* 用力拖拽时也会调一次
*/
override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
super.layoutAttributesForElements(in: rect)
return self.attrsArray
}
/// 返回collectionView的滚动范围
override var collectionViewContentSize: CGSize {
let _ = super.collectionViewContentSize
if (self.columnHeights.count == 0) {
return CGSize.zero
}
// 获得最高的列
let maxColum = self.maxHeightColumn()
let height: CGFloat = self.columnHeights[maxColum] + MGDefaultEdgeInsets.bottom;
let width: CGFloat = self.collectionView!.frame.size.width;
return CGSize(width: width, height: height)
}
}
// MARK: - 自定义方法
extension MGWaterFlowLayout {
/// 取得所有列中高度最短的列
fileprivate func minHeightColumn() -> Int {
// 找出columnHeights的最小值
var minHeightColum: Int = 0
var minColumHeight: CGFloat = self.columnHeights[0]
for i in 1..<columnHeights.count {
let tempHeight:CGFloat = self.columnHeights[i]
if (tempHeight < minColumHeight) {
minHeightColum = i;
minColumHeight = tempHeight;
}
}
return minHeightColum
}
/// 取得所有列中高度最高的列
fileprivate func maxHeightColumn() -> Int {
// 找出columnHeights的最高值
var maxHeightColumn: Int = 0
var maxColumnHeight: CGFloat = self.columnHeights[0]
for i in 1..<columnHeights.count {
let tempHeight:CGFloat = self.columnHeights[i]
if (tempHeight < maxColumnHeight) {
maxHeightColumn = i
maxColumnHeight = tempHeight
}
}
return maxHeightColumn
}
}
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