小编nul*_*ion的帖子

当你播放远程视频AVPlayer并开始倒带时,擦洗器就会出现问题.

我正在做一个基于这个Apple示例的玩家.

如何顺利实施？

我项目的代码如下 - https://github.com/nullproduction/Player

- (void)initScrubberTimer
{
    double interval = .1f;

    CMTime playerDuration = [self playerItemDuration];
    if (CMTIME_IS_INVALID(playerDuration))
    {
        return;
    }
    double duration = CMTimeGetSeconds(playerDuration);
    if (isfinite(duration))
    {
        CGFloat width = CGRectGetWidth([scrubberSlider bounds]);
        interval = 0.5f * duration / width;
    }

    __weak id weakSelf = self;
    CMTime intervalSeconds = CMTimeMakeWithSeconds(interval, NSEC_PER_SEC);
    mTimeObserver = [self.player addPeriodicTimeObserverForInterval:intervalSeconds
                                                              queue:dispatch_get_main_queue()
                                                         usingBlock:^(CMTime time) {
                                                             [weakSelf syncScrubber];
                                                         }];

}


- (void)syncScrubber
{
    CMTime playerDuration = [self playerItemDuration];
    if (CMTIME_IS_INVALID(playerDuration)) …

有一个包含 Catalyst 的 ios 项目。该项目具有无法针对 mac 架构进行编译的YandexMobileMetrica依赖项。如何使用 Swift Package Manager 添加仅限 iOS 的依赖项？

我尝试做两个目标。在第一个spm-test中，我禁用了 mac 标志。在第二个中，spm-test-mac离开了。我的 Package.swift 看起来像这样：

import PackageDescription

let package = Package(
    name: "spm-test",
    products: [
        .library(
            name: "spm-test",
            targets: ["spm-test"]),
    ],
    dependencies: [
        .package(name: "YandexMobileMetrica", url: "https://github.com/yandexmobile/metrica-sdk-ios", from: "3.14.1"),
    ],
    targets: [
        .target(
            name: "spm-test",
            dependencies: ["YandexMobileMetrica"]),
        .target(
            name: "spm-test-mac",
            dependencies: [])
    ]
) 

错误：

AppDelegate.swift:11:12: No such module 'YandexMobileMetrica'

我的 AppDelegate.swift

//  AppDelegate.swift
//

import UIKit

#if !targetEnvironment(macCatalyst)
    import YandexMobileMetrica …

我想在应用关闭时保存未完成的数据下载.

试过这样,但总是空的resumeData:

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(appWillTerminate) name:UIApplicationWillTerminateNotification object:nil];

- (void)appWillTerminate
{
    [self.downloadTask cancelByProducingResumeData:^(NSData *resumeData) {
        if (resumeData)
            [self saveData:resumeData];
        else
            NSLog(@"Not exist");
    }];
}

我在主线程中创建实体Artist,然后在后台线程中传递它并与实体相册相关联.

怎么做正确？

- (IBAction)add:(id)sender
{
    Artist *artist = [Artist MR_createEntity];
    artist.title = @"Eminem";

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0),^{
        // here a large calculation
        Album *album = [Album MR_createEntity];
        album.title = @"Album 1";
        [artist setAlbums:[NSSet setWithArray:@[album]]];

        dispatch_async(dispatch_get_main_queue(),^{
            [artist.managedObjectContext MR_saveToPersistentStoreAndWait];
        });
    });
}

错误:

MagicalRecordTest[2008:1803] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Illegal attempt to establish a relationship 'albums' between objects in different contexts (source = <Artist: 0x15eaa2d0>

我使用lib MagicalRecord(https://github.com/magicalpanda/MagicalRecord)进行CoreData.framework.

我不明白如何使用临时对象.

如何为临时对象创建NSManagedContext以及在关闭控制器后是否删除每个NSManagedObject？