iOS开发之高级视图—— UICollectionViewController

      可以继承UICollectionViewController来简化使用UICollectionView。UICollectionViewController中定义了一个 UICollectionView *collectionView，并且实现了 <UICollectionViewDelegate, UICollectionViewDataSource>协议，可以提示开发效率和简化开发。

     AppDelegate.m

////  AppDelegate.m//  UICollectionViewControllerApp////  Created by Apple on 16/5/26.//  Copyright © 2016年 Apple. All rights reserved.//#import "AppDelegate.h"#import "ViewController.h"@interface AppDelegate ()@end@implementation AppDelegate- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    // Override point for customization after application launch.        self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];    self.window.backgroundColor = [UIColor whiteColor];        // 创建布局对象，对UICollectionView进行控制    UICollectionViewFlowLayout* flowLayout = [[UICollectionViewFlowLayout alloc] init];        // 创建ViewController是设置flowLayout    // 如果直接创建不提供布局将包异常 UICollectionView must be initialized with a non-nil layout parameter    ViewController* viewController = [[ViewController alloc] initWithCollectionViewLayout:flowLayout];        //并设置ViewController为rootViewController    self.window.rootViewController = viewController;        [self.window makeKeyAndVisible];        return YES;}@end

    ViewController.h

////  ViewController.h//  UICollectionViewControllerApp////  Created by Apple on 16/5/26.//  Copyright © 2016年 Apple. All rights reserved.//#import <UIKit/UIKit.h>/* 简化使用UICollectionView，可以继承UICollectionViewController UICollectionViewController中定义了一个 UICollectionView *collectionView 并且实现了 <UICollectionViewDelegate, UICollectionViewDataSource>协议 */@interface ViewController : UICollectionViewController<UICollectionViewDelegateFlowLayout>@end

      ViewController.m

////  ViewController.m//  UICollectionViewControllerApp////  Created by Apple on 16/5/26.//  Copyright © 2016年 Apple. All rights reserved.//#import "ViewController.h"@interface ViewController ()@end@implementation ViewControllerstatic NSString * const reuseIdentifier = @"Cell";NSMutableArray* imgNames;- (void)viewDidLoad {    [super viewDidLoad];        imgNames = [[NSMutableArray alloc] init];    for (int i=1;i<=8; i++) {        [imgNames addObject:[NSString stringWithFormat:@"%d.jpg",i]];            }        [self.collectionView setBackgroundColor:[UIColor whiteColor]];    // Register cell classes    [self.collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:reuseIdentifier];    }#pragma mark <UICollectionViewDataSource>- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {        return [imgNames count];}- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {        UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:reuseIdentifier forIndexPath:indexPath];        // 创建一个UIImageView    UIImageView* imgView = [[UIImageView alloc]initWithImage:[UIImage imageNamed:imgNames [indexPath.row]]];        // 设置cell的背景    cell.backgroundView = imgView;            return cell;}#pragma mark - UICollectionViewDelegateFlowLayout//返回每个cell的大小- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath{        return CGSizeMake(self.view.frame.size.width/2-20, self.view.frame.size.height/3-10);}//设置每一个Cell的垂直和水平间距-(UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section{    //top    //left    //bottom    //right    return UIEdgeInsetsMake(10, 5, 10, 5);}#pragma mark <UICollectionViewDelegate>/* // Uncomment this method to specify if the specified item should be highlighted during tracking - (BOOL)collectionView:(UICollectionView *)collectionView shouldHighlightItemAtIndexPath:(NSIndexPath *)indexPath {return YES; } *//* // Uncomment this method to specify if the specified item should be selected - (BOOL)collectionView:(UICollectionView *)collectionView shouldSelectItemAtIndexPath:(NSIndexPath *)indexPath { return YES; } *//* // Uncomment these methods to specify if an action menu should be displayed for the specified item, and react to actions performed on the item - (BOOL)collectionView:(UICollectionView *)collectionView shouldShowMenuForItemAtIndexPath:(NSIndexPath *)indexPath {return NO; }  - (BOOL)collectionView:(UICollectionView *)collectionView canPerformAction:(SEL)action forItemAtIndexPath:(NSIndexPath *)indexPath withSender:(id)sender {return NO; }  - (void)collectionView:(UICollectionView *)collectionView performAction:(SEL)action forItemAtIndexPath:(NSIndexPath *)indexPath withSender:(id)sender { } */@end

      效果图如下：

      可以看到实现的效果与上一篇博客的效果一样的。