如何将标题信息插入 MPMoviePlayerController url？

Question

我需要使用 http 协议实现视频流服务。 我知道如何将 url 设置为 MPMoviePlayerController，以及如何将 headerField 设置为 NSMutableURLRequest，但我不知道如何组合它们。 我像下面的代码一样实现，但没有工作，我假设是因为二进制数据中没有文件信息。

- (void) openUrl
{
    NSMutableURLRequest *reqURL = [NSMutableURLRequest requestWithURL:
                               [NSURL URLWithString:@"http://111.222.33.44/MOV/2013/4/123123123"] cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:30.0];

    [reqURL setHTTPMethod:@"GET"];
    [reqURL setValue:@"Mozilla/4.0 (compatible;)" forHTTPHeaderField:@"User-Agent"];
    [reqURL setValue:@"AAA-bb" forHTTPHeaderField:@"Auth-Token"];
    [reqURL setValue:@"bytes=0-1024" forHTTPHeaderField:@"Range"];
    [reqURL setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];

    [NSURLConnection connectionWithRequest:reqURL delegate:self];

}


- (void) connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{    
    NSLog(@"Received");
    NSError * jsonERR = nil;

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *path = [documentsDirectory stringByAppendingPathComponent:@"myMove.ts"];

    [data writeToFile:path atomically:YES];
    NSLog(@"copied");
    NSURL *moveUrl = [NSURL fileURLWithPath:path];

    MPMoviePlayerController *player = [[MPMoviePlayerController alloc]init];
    [player setContentURL:moveUrl];
    player.view.frame = self.view.bounds;
    player.controlStyle = MPMovieControlStyleEmbedded;
    [self.view addSubview:player.view];
    [player play];
}

我确认delegate方法中有数据，但是不知道怎么玩。 请有人告诉我怎么玩。 Auth-Token 和 Range 是必要的参数。

谢谢。

Answer 1

确实，Apple 没有公开将标头注入MPMoviePlayerController 请求的简单方法。通过一些努力，您可以使用自定义NSURLProtocol 完成此操作。所以，让我们开始吧！

MyCustomURLProtocol.h：

@interface MyCustomURLProtocol : NSURLProtocol <NSURLConnectionDelegate, NSURLConnectionDataDelegate>

@property (nonatomic, strong) NSURLConnection* connection;

@end

MyCustomURLProtocol.m：

@implementation  MyCustomURLProtocol

// Define which protocols you want to handle
// In this case, I'm only handling "customProtocol" manually
// Everything else, (http, https, ftp, etc) is handled by the system
+ (BOOL) canInitWithRequest:(NSURLRequest *)request {
    NSURL* theURL = request.URL;
    NSString* scheme = theURL.scheme;
    if([scheme isEqualToString:@"customProtocol"]) {
        return YES;
    }
    return NO;
}

// You could modify the request here, but I'm doing my legwork in startLoading
+ (NSURLRequest *)canonicalRequestForRequest:(NSURLRequest *)request {
    return request;
}

// I'm not doing any custom cache work
+ (BOOL) requestIsCacheEquivalent:(NSURLRequest *)a toRequest:(NSURLRequest *)b {
    return [super requestIsCacheEquivalent:a toRequest:b];
}

// This is where I inject my header
// I take the handled request, add a header, and turn it back into http
// Then I fire it off
- (void) startLoading {
    NSMutableURLRequest* mutableRequest = [self.request mutableCopy];
    [mutableRequest setValue:@"customHeaderValue" forHTTPHeaderField:@"customHeaderField"];

    NSURL* newUrl = [[NSURL alloc] initWithScheme:@"http" host:[mutableRequest.URL host] path:[mutableRequest.URL path]];
    [mutableRequest setURL:newUrl];

    self.connection = [NSURLConnection connectionWithRequest:mutableRequest delegate:self];
}

- (void) stopLoading {
    [self.connection cancel];
}

// Below are boilerplate delegate implementations
// They are responsible for letting our client (the MPMovePlayerController) what happened

- (void) connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
    [self.client URLProtocol:self didFailWithError:error];
    self.connection = nil;
}

- (void) connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    [self.client URLProtocol:self didLoadData:data];
}

- (void) connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
    [self.client URLProtocol:self didReceiveResponse:response cacheStoragePolicy:NSURLCacheStorageAllowed];
}

- (void) connectionDidFinishLoading:(NSURLConnection *)connection {
    [self.client URLProtocolDidFinishLoading:self];
    self.connection = nil;
}

@end

在您可以使用您的自定义 URL 协议之前，您必须先注册它。在您的 AppDelegate.m 中：

#import "MyCustomURLProtocol.h"

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    // ... Your normal setup ...

    [NSURLProtocol registerClass:[MyCustomURLProtocol class]];

    return YES;
}

最后，您需要使用 MPMediaPlayerController 使用您的自定义 URL 协议。

NSString* theURLString = [NSString stringWithFormat:@"customProtocol://%@%@", [_url host],[_url path]];
_player = [[MPMoviePlayerController alloc] initWithContentURL:[NSURL URLWithString:theURLString]];

MPMoviePlayerController 现在将尝试使用customProtocol:// 而不是普通的http:// 发出请求。使用此设置，我们然后拦截该请求，添加我们的标头，将其转换为 http，然后关闭所有内容。

Answer 2

返回并阅读NSURLConnection 的文档以及一般的 URL 加载系统。 -connection:didReceiveData: 可能被多次调用，因为文件的每个块都到达了。您需要处理这个问题，而不是假设一次只有完整的数据到达。