Question

我正在学习android，我正在尝试在操作菜单中添加共享项。我为此引用http://developer.android.com/training/sharing/shareaction.html。但是item.getActionProvider（）在语句中返回null mShareActionProvider =（ShareActionProvider）item.getActionProvider（）; 。我试图在通过EditText给出名称的外部目录中播放视频文件。如果我直接传递意图，则播放视频文件。所以我确信，Intent没有问题这是完整的代码：

package com.example.sampleactivities;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;

import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.support.v4.view.MenuItemCompat;
import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.content.Intent;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.webkit.WebView.FindListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ShareActionProvider;
import android.widget.Toast;
import android.os.Build;

 public class UriTesting extends ActionBarActivity {

    public ShareActionProvider actionprovider;
    private Menu opmenu;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_uri_testing);

        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment())
                    .commit();
        }


    }

    @Override
    protected void onStart() {
        // TODO Auto-generated method stub
        super.onStart();

((Button)findViewById(R.id.SubmitForActionButton)).setOnClickListener(new OnClickListener() {

             @Override
            public void onClick(View arg0) {
            UriTesting.this.doshare();}});

}

     @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        this.opmenu=menu;
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.uri_testing, menu);
        MenuItem item=menu.findItem(R.id.menu_item_share);

        actionprovider=(ShareActionProvider)item.getActionProvider();

        if (actionprovider == null) {
            Toast.makeText(getApplicationContext(),"action provider is null",Toast.LENGTH_SHORT).show();}

        return super.onCreateOptionsMenu(menu);
    }

   private void doshare() {

        if(actionprovider==null)
        {
         MenuItem item=opmenu.findItem(R.id.menu_item_share);

         actionprovider=(ShareActionProvider)item.getActionProvider();

         if (actionprovider == null) {
            Toast.makeText(getApplicationContext(),"action provider is null ",Toast.LENGTH_SHORT).show();}
        }
        EditText url_edittext=(EditText)findViewById(R.id.urlreadingEditText);
        String filename=url_edittext.getText().toString();

        try {
            String encodedfilename = URLEncoder.encode(filename,"UTF-8");
              String PATH =  Environment.getExternalStorageDirectory()+"/Videos/"+encodedfilename.trim().toString();
              Uri url=Uri.parse("file://"+PATH);

            Intent intent=new Intent();
            intent.setAction(android.content.Intent.ACTION_VIEW);
            intent.setType("video/");
            intent.setData(url);



            //intent.setDataAndType(Uri.parse(url.toString()),"audio/");



            // Intent chooser=Intent.createChooser(intent, "select any");
            // startActivity(intent);

        Toast.makeText(getApplicationContext(),"sett",Toast.LENGTH_SHORT).show();
        if (actionprovider != null) {
            Toast.makeText(getApplicationContext(),"sett not null",Toast.LENGTH_SHORT).show();
           actionprovider.setShareIntent(intent);}
        }
        catch(Exception e)
        {
            Toast.makeText(getApplicationContext(),e.toString(),Toast.LENGTH_SHORT).show();
        }

    }
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        if(id==R.id.menu_item_share)
            doshare();
        return super.onOptionsItemSelected(item);
    }

这是菜单的

 <menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context="com.example.sampleactivities.UriTesting" >

    <item
        android:id="@+id/action_settings"
        android:orderInCategory="100"
        android:title="@string/action_settings"
        app:showAsAction="never"/>
     <item
        android:id="@+id/menu_item_share"

         android:title="share"
        app:actionProviderClass="android.widget.ShareActionProvider"

        app:showAsAction="ifRoom"/>

</menu>

Answer 1

如果您使用ActionBarActivity，则需要使用android.support.v7.widget.ShareActionProvider，而不是您正在使用的android.widget.ShareActionProvider。此外，您必须使用MenuItemCompat.getActionProvider()来检索ActionProvider，而不是直接致电getActionProvider()。

getActionProvider（）;在android中返回null

1 个答案: