遇到的问题
有时候要下载mp4,mp3等文件在沙盒下，通过播放器播放时候，无法播放，当资源在bundle下或者网上url时候能够正常播放，在沙盒下则没播放出来。
代码如下：
Bundle获取地址:
NSURL *bundleUrl = [[NSBundle mainBundle] URLForResource:@"1" withExtension:@"mp4"];
NSLog(@"bundle地址:%@",bundleUrl);
网络地址:
NSURL *videoUrl = [NSURL URLWithString:@"http://v.jxvdy.com/sendfile/DVVpy3JGQjjW02dR8N4SNJ4ZwDVREoa0GKsxcaL0qIX2ouTmQgKUS1p7XxxuZLE9-vS--xl7-eQvyCW-hvUvDKIu-HKRzw"];
NSLog(@"网络地址:%@",videoUrl);
沙盒地址
NSString *strPath = [NSString stringWithFormat:@"%@/Documents/1.mp4",NSHomeDirectory()];
NSLog(@"strPath:%@",strPath);
NSURL *sandbox1Url = [NSURL URLWithString:strPath];
NSLog(@"沙盒地址1:%@",sandbox1Url);
日志输出为:
strPath:
/Users/*/Documents/1.mp4沙盒地址1:
/Users/*/data/Containers/Data/App ... ts/1.mp4bundle地址:
file:///Users/*/AVPlayerDemo.app/1.mp4
经过日志分析：
使用沙盒地址跟网络地址,bundle地址明显缺失一个scheme,这就是问题所在。
- 正确方法
NSString *strPath = [NSString stringWithFormat:@"%@/Documents/1.mp4",NSHomeDirectory()];
NSLog(@"strPath:%@",strPath);
NSURL *sandboxUrl = [NSURL fileURLWithPath:strPath];
问题在于fileURLWithPath与URLWithString的区别，根本原因在于对URL的理解，摘抄Apple Documents
NSURL简介
An NSURL object represents a URL that can potentially contain the location of a resource on a remote server, the path of a local file on disk, or even an arbitrary piece of encoded data.
Structure of a URL
An NSURL object is composed of two parts—a potentially nil base URL and a string that is resolved relative to the base URL. An NSURL object is considered absolute if its string part is fully resolved without a base; all other URLs are considered relative.
For example, when constructing an NSURL object, you might specify file:///path/to/user/ as the base URL and folder/file.html as the string part, as follows:
NSURL *baseURL = [NSURL fileURLWithString:@"file:///path/to/user/"];
NSURL *URL = [NSURL URLWithString:@"folder/file.html" relativeToURL:baseURL];
NSLog(@"absoluteURL = %@", [URL absoluteURL]);
When fully resolved, the absolute URL is file:///path/to/user/folder/file.html.
A URL can be also be divided into pieces based on its structure. For example, the URL https://johnny:p4ssw0rd@www.example.com:443/script.ext;param=value?query=value#ref contains the following URL components:
| Component | Value |
|---|---|
| scheme | https |
| user | johnny |
| password | p4ssw0rd |
| host | www.example.com |
| port | 443 |
| path | /script.ext |
| pathExtension | ext |
| pathComponents | ["/", "script.ext"] |
| parameterString | param=value |
| query | query=value |
| fragment | ref |
The NSURL class provides properties that let you examine each of these components.
- 最根本的原因是URL中scheme不能缺失。也就是http://或者file://
fileURLWithPath与URLWithString的区别
其实两个Select都是返回一个Url，不同的是fileURLWithPath用在本地资源，而URLWithString更多的用在远程资源。最根本的原因是URL不能缺少scheme
这次使用出错的原因，也许是我们经常使用http请求接口或者图片:
NSURL *url = [NSURL URLWithString:@"www.baidu.com"];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
习惯性的用到URLWithString来生成NSUrl。
