空指针异常-android.support.v7.widget.ShareActionProvider

在过去的两个小时里，我正在编写一个简单的程序，但没有得到这个小问题的任何解决方案，使用以下代码：

MainActivity.java:-

@Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);

        // Set up ShareActionProvider's default share intent
        MenuItem shareItem = menu.findItem(R.id.share);

        ShareActionProvider mShareActionProvider = (ShareActionProvider)
                MenuItemCompat.getActionProvider(shareItem);

        mShareActionProvider.setShareIntent(getDefaultIntent());

        return super.onCreateOptionsMenu(menu);
    }

    private Intent getDefaultIntent() {
        Intent intent = new Intent(Intent.ACTION_SEND);
        intent.setType("text/plain");
        intent.putExtra(Intent.EXTRA_SUBJECT, "I am using Android App !!!");
        return intent;
    }
}

<menu xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:yourapp="http://schemas.android.com/apk/res-auto" >
     <item
        android:id="@+id/share"
        android:title="@string/share"
        yourapp:actionProviderClass="android.support.v7.widget.ShareActionProvider"
        yourapp:showAsAction="ifRoom" />

</menu>

main.xml:-

@Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);

        // Set up ShareActionProvider's default share intent
        MenuItem shareItem = menu.findItem(R.id.share);

        ShareActionProvider mShareActionProvider = (ShareActionProvider)
                MenuItemCompat.getActionProvider(shareItem);

        mShareActionProvider.setShareIntent(getDefaultIntent());

        return super.onCreateOptionsMenu(menu);
    }

    private Intent getDefaultIntent() {
        Intent intent = new Intent(Intent.ACTION_SEND);
        intent.setType("text/plain");
        intent.putExtra(Intent.EXTRA_SUBJECT, "I am using Android App !!!");
        return intent;
    }
}

<menu xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:yourapp="http://schemas.android.com/apk/res-auto" >
     <item
        android:id="@+id/share"
        android:title="@string/share"
        yourapp:actionProviderClass="android.support.v7.widget.ShareActionProvider"
        yourapp:showAsAction="ifRoom" />

</menu>

我跟着这个

日志显示：

02-20 05:51:48.814: E/AndroidRuntime(2012): FATAL EXCEPTION: main
02-20 05:51:48.814: E/AndroidRuntime(2012): Process: com.learn2crack.tab, PID: 2012
02-20 05:51:48.814: E/AndroidRuntime(2012): java.lang.NullPointerException
02-20 05:51:48.814: E/AndroidRuntime(2012):     at com.learn2crack.tab.MainActivity.onCreateOptionsMenu(MainActivity.java:79)
02-20 05:51:48.814: E/AndroidRuntime(2012):     at android.app.Activity.onCreatePanelMenu(Activity.java:2538)
02-20 05:51:48.814: E/AndroidRuntime(2012):     at android.support.v4.app.FragmentActivity.onCreatePanelMenu(FragmentActivity.java:224)
02-20 05:51:48.814: E/AndroidRuntime(2012):     at com.android.internal.policy.impl.PhoneWindow.preparePanel(PhoneWindow.java:436)
02-20 05:51:48.814: E/AndroidRuntime(2012):     at com.android.internal.policy.impl.PhoneWindow.doInvalidatePanelMenu(PhoneWindow.java:800)
02-20 05:51:48.814: E/AndroidRuntime(2012):     at com.android.internal.policy.impl.PhoneWindow$1.run(PhoneWindow.java:221)
02-20 05:51:48.814: E/AndroidRuntime(2012):     at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
02-20 05:51:48.814: E/AndroidRuntime(2012):     at android.view.Choreographer.doCallbacks(Choreographer.java:574)
02-20 05:51:48.814: E/AndroidRuntime(2012):     at android.view.Choreographer.doFrame(Choreographer.java:543)
02-20 05:51:48.814: E/AndroidRuntime(2012):     at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
02-20 05:51:48.814: E/AndroidRuntime(2012):     at android.os.Handler.handleCallback(Handler.java:733)
02-20 05:51:48.814: E/AndroidRuntime(2012):     at android.os.Handler.dispatchMessage(Handler.java:95)
02-20 05:51:48.814: E/AndroidRuntime(2012):     at android.os.Looper.loop(Looper.java:136)
02-20 05:51:48.814: E/AndroidRuntime(2012):     at android.app.ActivityThread.main(ActivityThread.java:5017)
02-20 05:51:48.814: E/AndroidRuntime(2012):     at java.lang.reflect.Method.invokeNative(Native Method)
02-20 05:51:48.814: E/AndroidRuntime(2012):     at java.lang.reflect.Method.invoke(Method.java:515)
02-20 05:51:48.814: E/AndroidRuntime(2012):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
02-20 05:51:48.814: E/AndroidRuntime(2012):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
02-20 05:51:48.814: E/AndroidRuntime(2012):     at dalvik.system.NativeStart.main(Native Method)
02-20 05:51:51.484: I/Process(2012): Sending signal. PID: 2012 SIG: 9

---

你可以试试这个，它对我有用

ShareActionProvider mShareActionProvider = new ShareActionProvider(getActivity());
MenuItemCompat.setActionProvider(shareItem, mShareActionProvider);

---

对我来说，问题出在proGuard。在我将其添加到规则文件后，问题解决了：

-keep class android.support.v7.widget.ShareActionProvider { *; }
-keep class android.support.v7.widget.SearchView { *; }

---

您是否检查了您的

shareItem

是否为空？您是否尝试过此操作以及此尝试

mShareActionProvider=（ShareActionProvider）shareItem.getActionProvider（）如果您尝试上述操作，会发生什么？@Raghunandan无法从ActionProvider转换为ShareActionProvider