Android 如何将ShareActionProvider添加到OnOptions ItemSelected

我是Android新手。我想在ActionBar的一个菜单中添加共享功能。actionbar中有两个菜单，分别是Share和Info

 @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();


    //noinspection SimplifiableIfStatement
    if (id == R.id.share) {
        mShareActionProvider = (ShareActionProvider) MenuItemCompat.getActionProvider(item);
        doShare();
        return true;
    }

    return super.onOptionsItemSelected(item);
}

private void doShare() {
    Intent intent = new Intent(Intent.ACTION_SEND);
    intent.setType("text/plain");
    intent.putExtra(Intent.EXTRA_TEXT,"Selected text");
    mShareActionProvider.setShareIntent(intent);
} 

在我添加代码行并运行应用程序之后。它返回错误Java空指针异常

FATAL EXCEPTION: main
Process: com.example, PID: 1222
java.lang.NullPointerException at com.example.MainActivity.doShare(MainActivity.java:94)
at com.example.MainActivity.onOptionsItemSelected(MainActivity.java:83)
at android.app.Activity.onMenuItemSelected(Activity.java:2617)

我搜索了一下，发现Android中的大部分教程都在教如何在OnCreateOptions菜单中添加ShareActionProvider，但我在操作栏中有两个菜单。如何从Actionbar中的选定菜单共享意图

试试这个：

doShare(mShareActionProvider)

...


private void doShare(ShareActionProvider mShareActionProvider) {
    Intent intent = new Intent(Intent.ACTION_SEND);
    intent.setType("text/plain");
    intent.putExtra(Intent.EXTRA_TEXT,"Selected text");
    mShareActionProvider.setShareIntent(intent);
} 

---

通过在OnCreateOptions菜单中设置ShareActionProvider的新实例，我可以使用它。我们使用setActionProvider而不是getActionProvider函数来共享意图

 @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        MenuItem item = menu.findItem(R.id.share);
        share = new ShareActionProvider(this);
        MenuItemCompat.setActionProvider(item, share);

        return(super.onCreateOptionsMenu(menu));
    }

    @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();

       //noinspection SimplifiableIfStatement
        if (id == R.id.share) {
            onShareAction();
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    private void onShareAction() {
        String yourShareText = "test";
        Intent shareIntent = ShareCompat.IntentBuilder.from(this).setType("text/plain").setText(yourShareText).getIntent();
        // Set the share Intent
        if (share != null) {
            share.setShareIntent(shareIntent);
        }
    } 

---

张贴你的堆栈trace@RuchirBaronia，我已经添加了痕迹，谢谢！你的第83行是什么@Micheletbs使该方法公开，并且tryits也不工作，当我调试时，它返回mShareActionProvider=null。为什么？