推出基于android系统中的文件的活动 [英] Launching an Activity based on a file in android

问题描述

我开发，其中列出文件夹中的文件的应用程序（在ListView）。当用户点击其中一个项目，如果它是一个文件，然后我想，推出了可以处理它，如果有的话，或显示某种错误消息，如果是没有的一种活动。

I am developing an application which lists files in a folder (in a ListView). When the user clicks on one of the items, if it is a file, then I would like to launch an activity that can handle it, if any, or display some kind of error message if there is none.

我怎样才能做到这一点？不是整个事情，当然，但我怎么能确定哪个应用程序（S）可以处理一个文件（如有）。

How can I do that? Not the whole thing, of course, but how can I determine which application(s) can handle a file, if any.

推荐答案

首先，你需要确定MIME类型的文件。为此，您可以使用 MimeTypeMap ：

First, you will need to determine the MIME type of the file. You can do this using MimeTypeMap:

MimeTypeMap map = MimeTypeMap.getSingleton();
String extension = map.getFileExtensionFromUrl(url); // url is the url/location of your file
String type = map.getMimeTypeFromExtension(extension);

然后，一旦你知道的MIME类型，您可以创建该类型的意图：

Then once you know the MIME type, you can create an intent for that type:

Intent intent = new Intent();
intent.setType(type);

最后，要检查是否有任何活动，能够解决与该类型的意图。这可以通过<一个进行href=\"http://developer.android.com/reference/android/content/pm/PackageManager.html\">PackageManager:

PackageManager manager = getPackageManager(); // I'm assuming this is done from within an activity. This a Context method.
List<ResolveInfo> resolvers = manager.queryIntentActivities(intent, 0);
if (resolvers.isEmpty()) {
  // display error
} else {
  // launch the intent. You will also want to set the data based on the uri of your file
}

这篇关于推出基于android系统中的文件的活动的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！