iOS:在应用程序启动时播放视频

Question

我是 Xcode 的新手，所以我一直在尝试按照教程进行操作，但没有遇到任何解释我正在努力实现的目标的教程。我只想在您打开应用程序时自动播放视频。我有一些工作，因为音频播放，但我看不到任何视频。我错过了什么吗？我在输出窗口中收到此警告:

Warning: Attempt to present MPMoviePlayerViewController: 0x831d7a0 on ViewController: 0x9d10540 whose view is not in the window hierarchy!

在我的 ViewController.h 中:

#import <UIKit/UIKit.h>
#import <MediaPlayer/MediaPlayer.h>

@interface ViewController : UIViewController

@end

ViewController.m:

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController


- (void)viewDidLoad
{
    [super viewDidLoad];
    NSURL *url =[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"Placeholder" ofType:@"mp4"]];
    MPMoviePlayerViewController *playercontroller = [[MPMoviePlayerViewController alloc] initWithContentURL:url];
    [self presentMoviePlayerViewControllerAnimated:playercontroller];
    playercontroller.moviePlayer.movieSourceType = MPMovieSourceTypeFile;
    [playercontroller.moviePlayer play];
    playercontroller = nil;

}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

Answer 1

代替

[playercontroller.moviePlayer play];

做

[playercontroller play];

旁注: 还要检查您的命名约定。在 Objective-C 中，变量名“应该”在变量中的每个新词上都有大写字母。例如。而不是 playercontroller 使用 playerController。