android：如何从我的应用程序中打开文件

Question

I'm developing an app, which should open a file after decoding. So, I want to open a file (for example an image) picked in my app by a default application (if there are several apps for that kind of file then one of apps is to choose by user).

Answer 1

For different file types you need to use different intents like the below

Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent,
"Open image"), 1);

or you could use the following code to get the file type from the file and letthe android system figure out which app it can be opened with

File file = new File("EXAMPLE.JPG");


String mime = MimeTypeMap.getSingleton().getMimeTypeFromExtension(".JPG");
//You need to find the extension from the file using a split command
Intent intent = new Intent();
intent.setAction(android.content.Intent.ACTION_VIEW);
intent.setDataAndType(Uri.fromFile(file), mime);
startActivityForResult(intent, 10);