Simple use of iOS basics _ Uicollectionview

There are two ways to use uicollectionview like table view

One is inherit Uicollectionviewcontroller, this controller will bring a uicollectionview;

The other is to create a uiconllectionview view that is placed inside the normal Uiviewcontroller.

We use the second type of

first declare a declaration first Reuse Markers and implement a delegate

#define _cell @"Acell"

@interfaceyxpviewcontroller () <Uicollectionviewdatasource, uicollectionviewdelegate , Uicollectionviewdelegateflowlayout >

Then initialize the Uicollectionview

-(void) Initcollectionview

{

//Instantiate a layer first

uicollectionviewflowlayout *layout=[[uicollectionviewflowlayoutalloc] init];

//Create one-screen view size

uicollectionview *collectionview=[[uicollectionviewalloc] initwithframe: self. View. bounds collectionviewlayout: layout];

[CollectionViewregisterclass: [Uicollectionviewcellclass] Forcellwithreuseidentifier:_cell];

CollectionView. backgroundcolor=[uicolorwhitecolor];

CollectionView. delegate=self;

CollectionView. DataSource=self;

[Self. View addsubview: CollectionView];

}

Implementing Proxy methods

#pragma Mark--uicollectionviewdatasource

Defines the number of Uicollectionviewcell to show

-(Nsinteger) CollectionView: (uicollectionview *) CollectionView numberofitemsinsection: ( Nsinteger) Section

{

return ;

}

Define the number of sections to show

-(Nsinteger) Numberofsectionsincollectionview: (uicollectionview *) CollectionView

{

return 1;

}

What each Uicollectionview shows

-(uicollectionviewcell *) CollectionView: (uicollectionview *) CollectionView Cellforitematindexpath: (nsindexpath *) Indexpath

{

Uicollectionviewcell * cell = [CollectionViewdequeuereusablecellwithreuseidentifier :_cellforindexpath: Indexpath];

cell.BackgroundColor = [UicolorColorwithred:((Arc4random()%255)/255.0)Green:((Arc4random()%255)/255.0)Blue:((Arc4random()%255)/255.0)Alpha:1.0f];

return cell;

}

#pragma Mark--uicollectionviewdelegate

method to invoke when Uicollectionview is selected

-(void) CollectionView: (uicollectionview *) CollectionView Didselectitematindexpath: ( Nsindexpath *) Indexpath

{

Uicollectionviewcell * cell = (uicollectionviewcell *) [CollectionViewCellforitematindexpath : Indexpath];

cell.BackgroundColor = [UicolorColorwithred:((Arc4random()%255)/255.0)Green:((Arc4random()%255)/255.0)Blue:((Arc4random()%255)/255.0)Alpha:1.0f];

}

Returns whether this Uicollectionviewcell can be selected

-(BOOL) CollectionView: (uicollectionview *) CollectionView Shouldselectitematindexpath: ( Nsindexpath *) Indexpath

{

return YES;

}

#pragma Mark--uicollectionviewdelegateflowlayout

Define the size of each Uicollectionview

-(cgsize) CollectionView: (uicollectionview *) CollectionView layout: (uicollectionviewlayout *) collectionviewlayout Sizeforitematindexpath: (nsindexpath *) Indexpath

{

return Cgsizemake (a);

}

Define margins for each Uicollectionview

-(uiedgeinsets) CollectionView: (uicollectionview *) CollectionView layout: ( Uicollectionviewlayout *) collectionviewlayout insetforsectionatindex: (nsinteger) Section

{

return Uiedgeinsetsmake (Ten, 10 ,ten);

}

such a simple uicollection view is done