我想在我的应用程序使用android.support.v7.widget.ShareActionProvider的动作条。所以我也跟着从Android电子文档中的例子，但有一些问题。 这是我的菜单的xml：

I tried to use android.support.v7.widget.ShareActionProvider on actionbar in my app. So I followed the example from android document but got some issues. Here's my menu xml:

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:myapp="http://schemas.android.com/apk/res-auto" >

    <item
        android:id="@+id/action_share"
        android:orderInCategory="100"
        android:icon="@drawable/ic_action_share"
        android:title="@string/action_share"
        myapp:showAsAction="ifRoom"
        myapp:actionProviderClass="android.support.v7.widget.ShareActionProvider" />

</menu>

这是我的code创建共享操作按钮：

here's my code to create the share action button:

@Override
public void onCreateOptionsMenu (Menu menu, MenuInflater inflater) {
    inflater.inflate(R.menu.share, menu);
    MenuItem shareItem = menu.findItem(R.id.action_share);
    ShareActionProvider mShareActionProvider = (ShareActionProvider)MenuItemCompat.getActionProvider(shareItem);
    mShareActionProvider.setShareIntent(getDefaultIntent());
    super.onCreateOptionsMenu(menu, inflater);
}

我的问题是：

My question is:

顺便说一句，我检查$ C $ MenuItemCompat.getActionProvider的CS，它看起来像这种方法将检查菜单项实现SupportMenuItem界面并返回失​​败，如果事实并非如此。我怎么能解决呢？

btw, I checked codes of MenuItemCompat.getActionProvider, it looks like this method will check if the menu item implements SupportMenuItem interface and returns fail if it isn't. How could I deal with it?

推荐答案

下面这个是工程，使ShareActionProvider NOT NULL唯一的解决办法...我使用设置ActionProvider，而不是...请参见下面的code：

Here this is the only solution that works to make ShareActionProvider not null...i use set ActionProvider instead...see the code below:

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.messages_activity_menu, menu);
    MenuItem menuItem = menu.findItem(R.id.menu_item_share);
    shareActionProvider = new ShareActionProvider(this);
    MenuItemCompat.setActionProvider(menuItem, shareActionProvider);

    return super.onCreateOptionsMenu(menu);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    if(item.getItemId() == R.id.menu_item_share){
        onShareAction();
    }

    return super.onOptionsItemSelected(item);
}

private void onShareAction(){
    // Create the share Intent
    String playStoreLink = "https://play.google.com/store/apps/details?id=" + getPackageName();
    String yourShareText = getResources().getString(R.string.share_text) + playStoreLink;
    Intent shareIntent = ShareCompat.IntentBuilder.from(this).setType("text/plain").setText(yourShareText).getIntent();
    // Set the share Intent
    if (shareActionProvider != null) {
        shareActionProvider.setShareIntent(shareIntent);
    }
}

和... XML

 <?xml version="1.0" encoding="utf-8"?>
 <menu xmlns:android="http://schemas.android.com/apk/res/android" >
     <item
    android:id="@+id/menu_item_share"
    android:icon="@drawable/ic_action_share"
    android:showAsAction="ifRoom|withText"
    android:title="@string/menu_item_share" />
 </menu>

和可检查其它东西：

该活动已扩展ActionBarActivity：

the activity has to extends ActionBarActivity:

MyActivity extends ActionBarActivity

检查并使用进口：

check and use this imports:

import android.support.v4.app.ShareCompat;
import android.support.v4.view.MenuItemCompat;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBar.OnNavigationListener;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.widget.ShareActionProvider;

在AndroidManifest.xml中把这个线在活动的标签属性：

In AndroidManifest.xml put this line in your activity's tag attributes:

android:theme="@style/Theme.AppCompat.Light"

如果你不知道如何导入V7和V4兼容库看到：http://developer.android.com/tools/support-library/setup.html

If you dont know how to import v7 and v4 compatibility libraries see: http://developer.android.com/tools/support-library/setup.html