OC Waterfall can be expanded HEADVIEW_OC

1.swvideocollectionview.h encapsulates CollectionView in the Swvideocollectionview class.

#import <UIKit/UIKit.h>

@protocol swvideocollectionviewdelegate <NSObject>

/**

* Click on the cell method

*/

-(void) Videocollectionview: (UIView *) View index: (nsinteger) index;

/**

* Click the Avatar method

*/

-(void) Videocollectionphotoview: (UIView *) View index: (nsinteger) index;

@optional

-(Uicollectionreusableview *) CollectionView: (Uicollectionview *) CollectionView Viewforsupplementaryelementofkind :(NSString *) kind Atindexpath: (Nsindexpath *) Indexpath;

-(void) Scrollviewdidscroll: (UIView *) View ScrollView: (Uiscrollview *) ScrollView Contentoffset: (cgpoint) Contentoffset;

@end

@interface Swvideocollectionview:uiview

-(Instancetype) initWithFrame: (CGRect) frame headerreferencesize: (cgsize) headerreferencesize headClass: (NSString *) Headclass;

@property (nonatomic,weak) Uicollectionview *collectionview;

@property (Nonatomic,strong) Nsarray *datalists;

@property (assign) id<swvideocollectionviewdelegate>delegate;

@end

1.swvideocollectionview.m

#import "SWVideoCollectionView.h"

#import "SWImgCollectionFlowLayout.h"

#import "SWMainDetailCollectionViewCell.h"

#import "SWVideoListModel.h"

#define CELLCOUNT 2

@interface Swvideocollectionview () <uicollectionviewdatasource,uicollectionviewdelegate, Uicollectionviewdelegateflowlayout,swmaindetailcollectionviewcelldelegate>

@property (nonatomic,copy) NSString *headclass;

@end

Static NSString *maindetailid =@ "Maindetailid";

Static NSString *headscrollid =@ "Headscrollid";

@implementation Swvideocollectionview

-(Instancetype) initWithFrame: (CGRect) frame headerreferencesize: (cgsize) headerreferencesize headClass: (NSString *) Headclass {

if (self = [superinitwithframe:frame]) {

Swimgcollectionflowlayout *layout = [[Swimgcollectionflowlayoutalloc] init];

if (headerreferencesize.height!=0 && headerreferencesize.width!=0) {

Layout.headerreferencesize = headerreferencesize;

}

Layout.columncount =cellcount;

Layout.minimumlinespacing =kkpadding * 0.5;

Layout.minimuminteritemspacing =kkpadding *0.5;

Layout.sectioninset =uiedgeinsetsmake (kkpadding *0.5, kkpadding *0.5, kkpadding *0.5, kkPadding *0.5);

Uicollectionview *collectionview = [[Uicollectionviewalloc] initWithFrame:self.boundscollectionViewLayout:layOut];

Collectionview.tag =self.tag;

Self.collectionview = CollectionView;

Collectionview.showshorizontalscrollindicator =no;

Collectionview.showsverticalscrollindicator =no;

[CollectionView Registerclass:[swmaindetailcollectionviewcellclass] forcellwithreuseidentifier:maindetailid];

if (Headclass!=nil) {

Self.headclass = Headclass;

[CollectionView registerclass:nsclassfromstring (Headclass) Forsupplementaryviewofkind: Uicollectionelementkindsectionheaderwithreuseidentifier:headscrollid];

}

Collectionview.backgroundcolor =KKLIGHTGRAYBG;

Collectionview.datasource =self;

Collectionview.delegate =self;

[Selfaddsubview:collectionview];

}

returnself;

}

#pragma mark-collectionview Agent

-(Nsinteger) CollectionView: (Uicollectionview *) CollectionView numberofitemsinsection: (NSInteger) Section {

if (!self.datalists | | Self.dataLists.count ==0) {

Swvideolistmodel *model = [[Swvideolistmodelalloc] init];

model.goods_id =@ "-1";

Self.datalists = [Nsarrayarraywithobjects:model, nil];

}

Returnself.dataLists.count;

}

-(Uicollectionviewcell *) CollectionView: (Uicollectionview *) CollectionView Cellforitematindexpath: (NSIndexPath *) Indexpath {

Swmaindetailcollectionviewcell *cell = [Collectionviewdequeuereusablecellwithreuseidentifier: Maindetailidforindexpath:indexpath];

Cell.tag = Indexpath.row;

Cell.delegate =self;

Cell.videomodel =self.datalists[indexpath.row];

return cell;

}

#pragma mark-click cell

-(void) CollectionView: (Uicollectionview *) CollectionView Didselectitematindexpath: (Nsindexpath *) IndexPath {

Swvideolistmodel *listmodel =self.datalists[indexpath.row];

if ([listmodel.goods_idisequaltostring:@ "-1"]) {

Return

}

[Self.delegatevideoCollectionView:selfindex:indexPath.row];

}

#pragma mark-click Avatar

-(void) Maindetailcollectionviewcell: (Uicollectionviewcell *) Cell {

Swvideolistmodel *listmodel =self.datalists[cell.tag];

if ([listmodel.goods_idisequaltostring:@ "-1"]) {

Return

}

[Self.delegatevideoCollectionPhotoView:selfindex:cell.tag];

}

The size of the #pragma mark-cell is used for waterfall flow computed values

-(Cgsize) CollectionView: (Uicollectionview *) CollectionView layout: (uicollectionviewlayout *) collectionviewlayout Sizeforitematindexpath: (Nsindexpath *) Indexpath {

Swvideolistmodel *info =self.datalists[indexpath.row];

if ([info.goods_idisequaltostring:@ "-1"]) {

Returncgsizemake (0,0);

}

CGFloat itemwidth = (Self.frame.size.width-(cellcount + 1) *kkpadding * 0.5)/cellcount;

CGFloat ITEMH = itemwidth;

if (info.default_image_height >0 && info.default_image_width >0) {

ITEMH = [Info.default_image_heightfloatvalue] * itemwidth/[info.default_image_widthfloatvalue];

}

Other text height settings

CGFloat Marin =kkpadding * 1.5;

CGFloat txtheight = marin;//distance from bottom margin

TxtHeight + 35 *0.5;//head height

CGFloat titleheight = [info._descriptionboundingheightwithwidth:itemwidth-kkpadding dict:kkFont13];

TxtHeight + = Titleheight;

ITEMH + = TxtHeight;

Returncgsizemake (Itemwidth, ITEMH);

}

#pragma mark-Expand header File optional

-(Uicollectionreusableview *) CollectionView: (Uicollectionview *) CollectionView Viewforsupplementaryelementofkind :(NSString *) kind Atindexpath: (Nsindexpath *) Indexpath {

return [Self.delegatecollectionView:collectionViewviewForSupplementaryElementOfKind:kindatIndexPath:indexPath];

}

#pragma mark-Listening for scrolling offset optional

-(void) Scrollviewdidscroll: (Uiscrollview *) ScrollView {

if ([Self.delegaterespondstoselector: @selector (scrollViewDidScroll:scrollView:contentOffset:)]) {

[Self.delegatescrollViewDidScroll:selfscrollView:scrollView ContentOffset:scrollView.contentOffset];

}

}

#pragma mark-setting up a data source

-(void) Setdatalists: (Nsarray *) datalists {

_datalists = datalists;

[Self.collectionviewreloaddata];

}

@end

3. Custom Swheadscrollviewcell, Swmaindetailcollectionviewcell. Implement Maindetailcollectionviewcell Agent. Rewrite layoutsubviews

4. Custom Uicollectionviewflowlayout UICOLLECTIONVIEWFLOWLAYOUT.M

#import "SWImgCollectionFlowLayout.h"

@interface Swimgcollectionflowlayout ()

@property (Nonatomic,strong) nsmutabledictionary *attributes;

@property (Nonatomic,strong) Nsmutablearray *colarr;

@property (nonatomic,assign) uiedgeinsets edgeinsets;

@property (Nonatomic,weak) id<uicollectionviewdelegateflowlayout> delegate;

@property (Nonatomic,strong) Nsmutablearray *layoutattributesarray;

@end

@implementation Swimgcollectionflowlayout

-(void) Preparelayout {

Class

Self.attributes = [[Nsmutabledictionaryalloc] init];

Self.layoutattributesarray = [Nsmutablearrayarray];

Self.colarr = [NSMutableArrayarrayWithCapacity:self.columnCount];

Self.delegate = (id<uicollectionviewdelegateflowlayout>) self.collectionView.delegate;

Get the total number

Nsuinteger itemCount = [self.collectionviewnumberofitemsinsection:0];

if (!itemcount) {

Return

}

_colarr is used to store adjacent three heights.

CGFloat top =.0f;

For (Nsuinteger idx =0; idx < self.columncount; idx++) {

[_colarraddobject:[nsnumbernumberwithfloat:top]];

}

Append header file layout.

Nsarray *attributesarray1 = [Superlayoutattributesforelementsinrect:cgrectmake (0,0, Self.collectionview.frame.size.width,self.collectionview.frame.size.height)];

For (uicollectionviewlayoutattributes *headattributesin attributesArray1) {

if (Headattributes.representedelementkind ==uicollectionelementkindsectionheader) {

[Self.layoutAttributesArrayaddObject:headAttributes];

}

}

Iterate through all the item and rearrange the layout

For (Nsuinteger idx =0; idx < itemCount; idx++) {

[Selflayoutitematindexpath:[nsindexpathindexpathforitem:idx insection:0]];

}

}

//

-(void) Layoutitematindexpath: (Nsindexpath *) Indexpath {

Get the CollectionView edgeinsets

Uiedgeinsets edgeinsets =self.sectioninset;

if ([Self.delegaterespondstoselector: @selector (collectionView:layout:insetForSectionAtIndex:)]) {

Edgeinsets = [Self.delegatecollectionView:self.collectionViewlayout:selfinsetForSectionAtIndex:indexPath.row];

}

Self.edgeinsets = edgeinsets;

Get the CollectionView itemsize

Cgsize itemsize =self.itemsize;

if ([Self.delegaterespondstoselector: @selector (CollectionView:layout:sizeForItemAtIndexPath:)]) {

ItemSize = [Self.delegatecollectionView:self.collectionViewlayout:selfsizeForItemAtIndexPath:indexPath];

}

Traverse adjacent three heights to get the minimum height

Nsuinteger col = 0;

CGFloat shortheight = [[_colarrfirstobject] floatvalue];

For (Nsuinteger idx =0; idx < _colarr.count; idx++) {

CGFloat height = [_colarr[id