Question

When a user downloads a file using Android I want my custom activity to be launched to open that file. For example, my custom activity should show up in the ‘Complete action using’ alert box when the file is launched.

Is there any examples to see how this is done?

Answer 1

If I am correct, this will be what you want in your manifest:

<activity
     android:name=".NameOfYourActivity"
     android:label="@string/app_name" >
            <intent-filter>
                  <action android:name="android.intent.action.VIEW" />
                  <category android:name="android.intent.category.DEFAULT" />
                  <data android:mimeType="text/plain" />
            </intent-filter>
</activity>

For more information, read Intents and Intent Filters from the developer website.

Also, here is a sample of an activity you could use to display a file.

public class MIMEsActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);


    //Get the intent that has the information about the file.
    Intent sender = getIntent();

    //In this example I'm simply displaying the file's contents
    //in a TextView.
    TextView view = (TextView) findViewById(R.id.textview);

    //Check to see if there was an intent sent.
    if(sender != null) {

        //Get the file.
        File file = new File(sender.getData().getPath());

        /*
            DO STUFF HERE WITH THE FILE
            I load the text of the file and send it
            to the TextView.
        */
        StringBuilder text = new StringBuilder();
        try {
            BufferedReader br = new BufferedReader(new FileReader(file));
            String line;

            while ((line = br.readLine()) != null) {
                text.append(line);
                text.append('\n');
            }
        }
        catch (IOException e) {
            //You'll need to add proper error handling here
        }

        view.setText("PATH: " + sender.getData().getPath() + "\n\n" + text);
        //Done doing stuff.
    }
    //If an intent was not sent, do something else.
    else {
        view.setText("You did not get a file!");
    }

}

}