我在scrollview中添加了多个AVPlayer对象。这是第一次工作正常，但当我回到我以前的视图并再次回来时，我无法在scrollView中看到AVPlayer对象。
我需要多个AVPlayer的矩阵来显示我的视频的缩略图。
请尽快帮助我
提前致谢。
答案 0 :(得分：5)
我遇到了类似的问题，经过大量搜索后发现AVPLayerItem对象导致了这个问题。
基本上当AVPlayer项目离开屏幕时，您需要确保所有内容都正确释放，然后在屏幕上重新显示所有内容。
作为发布过程的一部分，请包含以下行：
[AVPlayer replaceCurrentItemWithPlayerItem:nil];
这为我排序了一个非常类似的问题。
答案 1 :(得分：0)
[AVPlayer replaceCurrentItemWithPlayerItem:nil];
也解决了我无法立即释放当前玩家项目的问题。 （不能手动这样做，因为它是由班级保留的。）
答案 2 :(得分：0)
以下是你如何在同一个scrollView中同时播放10个AVPlayers，每次滚动它时：
//
// ViewController.m
// VideoWall
//
// Created by James Alan Bush on 6/13/16.
// Copyright © 2016 James Alan Bush. All rights reserved.
//
#import "ViewController.h"
#import "AppDelegate.h"
static NSString *kCellIdentifier = @"Cell Identifier";
@interface ViewController () {
dispatch_queue_t dispatchQueueLocal;
}
@end
@implementation ViewController
- (id)initWithCollectionViewLayout:(UICollectionViewFlowLayout *)layout
{
if (self = [super initWithCollectionViewLayout:layout])
{
[self.collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:kCellIdentifier];
dispatchQueueLocal = dispatch_queue_create( "local session queue", DISPATCH_QUEUE_CONCURRENT );
}
return self;
}
- (void)viewDidLoad {
[super viewDidLoad];
[self.collectionView setDataSource:self];
[self.collectionView setContentSize:CGSizeMake(AppDelegate.sharedAppDelegate.width, AppDelegate.sharedAppDelegate.height)];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
}
- (void)dealloc {
[super dealloc];
}
#pragma mark <UICollectionViewDataSource>
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
return 1;
}
#pragma mark - UICollectionViewDataSource
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
return AppDelegate.sharedAppDelegate.assetsFetchResults.count;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
UICollectionViewCell *cell = (UICollectionViewCell *)[collectionView dequeueReusableCellWithReuseIdentifier:kCellIdentifier forIndexPath:indexPath];
[CATransaction begin];
[CATransaction setCompletionBlock:^{
cell.contentView.layer.sublayers = nil;
dispatch_release(dispatchQueueLocal);
}];
dispatch_retain(dispatchQueueLocal);
dispatch_async( dispatchQueueLocal, ^{
[self drawPlayerLayerForCell:cell atIndexPath:indexPath];
});
[CATransaction commit];
return cell;
}
- (void)drawPlayerLayerForCell:(UICollectionViewCell *)cell atIndexPath:(NSIndexPath *)indexPath {
void (^drawPlayerLayer)(UICollectionViewCell*, NSIndexPath*) = ^(UICollectionViewCell* cell, NSIndexPath* indexPath) {
[AppDelegate.sharedAppDelegate.imageManager requestPlayerItemForVideo:AppDelegate.sharedAppDelegate.assetsFetchResults[indexPath.item] options:nil resultHandler:^(AVPlayerItem * _Nullable playerItem, NSDictionary * _Nullable info) {
dispatch_async(dispatch_get_main_queue(), ^{
if(![[info objectForKey:PHImageResultIsInCloudKey] boolValue]) {
AVPlayerLayer *playerLayer = [AVPlayerLayer playerLayerWithPlayer:[AVPlayer playerWithPlayerItem:playerItem]];
[playerLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
[playerLayer setBorderColor:[UIColor whiteColor].CGColor];
[playerLayer setBorderWidth:1.0f];
[playerLayer setFrame:cell.contentView.bounds];
[cell.contentView.layer addSublayer:playerLayer];
[(AVPlayer *)playerLayer.player play];
} else {
[AppDelegate.sharedAppDelegate.imageManager requestImageForAsset:AppDelegate.sharedAppDelegate.assetsFetchResults[indexPath.item]
targetSize:CGSizeMake(AppDelegate.sharedAppDelegate.flowLayout.itemSize.width, AppDelegate.sharedAppDelegate.flowLayout.itemSize.height)
contentMode:PHImageContentModeAspectFill
options:nil
resultHandler:^(UIImage *result, NSDictionary *info) {
dispatch_async(dispatch_get_main_queue(), ^{
cell.contentView.layer.contents = (__bridge id)result.CGImage;
});
}];
}
});
}];
};
drawPlayerLayer(cell, indexPath);
}
@end
这是AppDelegate实施文件：
//
// AppDelegate.m
// VideoWall
//
// Created by James Alan Bush on 6/13/16.
// Copyright © 2016 James Alan Bush. All rights reserved.
//
#import "AppDelegate.h"
#import "ViewController.h"
@implementation AppDelegate
+ (AppDelegate *)sharedAppDelegate
{
return (AppDelegate *)[[UIApplication sharedApplication] delegate];
}
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// Override point for customization after application launch
self.width = [[UIScreen mainScreen] bounds].size.width / 2.0;
self.height = [[UIScreen mainScreen] bounds].size.height / 4.0;
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.window.rootViewController = [self viewController];
self.window.rootViewController.view = self.viewController.view;
[self.window makeKeyAndVisible];
return YES;
}
- (ViewController *)viewController {
ViewController *c = self->_viewController;
if (!c) {
c = [[ViewController alloc] initWithCollectionViewLayout:[self flowLayout]];
[c.view setFrame:[[UIScreen mainScreen] bounds]];
self->_viewController = c;
}
return c;
}
- (UICollectionViewFlowLayout *)flowLayout {
UICollectionViewFlowLayout *v = self->_flowLayout;
if (!v) {
v = [UICollectionViewFlowLayout new];
[v setItemSize:CGSizeMake(AppDelegate.sharedAppDelegate.width, AppDelegate.sharedAppDelegate.height)];
[v setSectionInset:UIEdgeInsetsMake(0.0, 0.0, 0.0, 0.0)];
[v setMinimumLineSpacing:0.0];
[v setMinimumInteritemSpacing:0.0];
[v setEstimatedItemSize:CGSizeMake(AppDelegate.sharedAppDelegate.width, AppDelegate.sharedAppDelegate.height)];
self->_flowLayout = v;
}
return v;
}
- (PHCachingImageManager *)imageManager {
PHCachingImageManager *i = self->_imageManager;
if (!i) {
i = [[PHCachingImageManager alloc] init];
self->_imageManager = i;
}
return i;
}
- (PHFetchResult *)assetsFetchResults {
PHFetchResult *i = self->_assetsFetchResults;
if (!i) {
PHFetchResult *smartAlbums = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum subtype:PHAssetCollectionSubtypeSmartAlbumVideos options:nil];
PHAssetCollection *collection = smartAlbums.firstObject;
if (![collection isKindOfClass:[PHAssetCollection class]])
return nil;
PHFetchOptions *allPhotosOptions = [[PHFetchOptions alloc] init];
allPhotosOptions.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"creationDate" ascending:NO]];
i = [PHAsset fetchAssetsInAssetCollection:collection options:allPhotosOptions];
self->_assetsFetchResults = i;
}
return i;
}
- (void)applicationWillResignActive:(UIApplication *)application {
// Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
// Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
}
- (void)applicationDidEnterBackground:(UIApplication *)application {
// Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
// If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}
- (void)applicationWillEnterForeground:(UIApplication *)application {
// Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
}
- (void)applicationDidBecomeActive:(UIApplication *)application {
// Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}
- (void)applicationWillTerminate:(UIApplication *)application {
// Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
}
@end
这是您需要的唯一两个文件;没有NIB / XIB。