空指针异常使用支持库共享行动提供商 [英] Null Pointer exception in using support library share action provider
问题描述
下面是我的活动的code。在此我使用的是支持库appcompat
进口android.content.Intent;
进口android.os.Bundle;
进口android.support.v4.view.MenuItemCompat;
进口android.support.v7.app.ActionBarActivity;
进口android.support.v7.widget.ShareActionProvider;
进口android.view.Menu;
进口android.view.MenuItem;
公共类MainActivity扩展ActionBarActivity {
@覆盖
保护无效的onCreate(包savedInstanceState){
super.onCreate(savedInstanceState);
的setContentView(R.layout.activity_main);
}
@覆盖
公共布尔onCreateOptionsMenu(功能菜单){
//充气菜单;这增加了项目操作栏,如果它是present。
。getMenuInflater()膨胀(R.menu.activity_main,菜单);
菜单项项=(菜单项)menu.findItem(R.id.share_options);
ShareActionProvider shareAction =(ShareActionProvider)MenuItemCompat
.getActionProvider(项目);
意图shareIntent =新的意图(Intent.ACTION_SEND)
.setAction(Intent.ACTION_SEND)
.putExtra(Intent.EXTRA_TEXT,MobiTexter)
.setType(text / plain的);
shareAction.setShareIntent(shareIntent);
返回super.onCreateOptionsMenu(菜单);
}
}
以下是我的XML文件菜单选项是ShareActionProvider小部件
<菜单的xmlns:机器人=http://schemas.android.com/apk/res/android
的xmlns:mobitexter =http://schemas.android.com/apk/res-auto>
<项目
机器人:ID =@ + ID / share_options
机器人:actionProviderClass =android.support.v7.widget.ShareActionProvider
机器人:orderInCategory =100
mobitexter:showAsAction =从不
mobitexter:标题=@字符串/ share_options/>
< /菜单>
在此,我得到一个NullPointerException异常。下面是我的日志猫输出。
一十二月10日至2号:49:00.813:E / AndroidRuntime(9227):致命异常:主要
十二月一十号至2日:49:00.813:E / AndroidRuntime(9227):显示java.lang.NullPointerException
十二月一十号至2日:49:00.813:E / AndroidRuntime(9227):在net.mobitexter.easyshare.MainActivity.onCreateOptionsMenu(MainActivity.java:31)
十二月一十号至2日:49:00.813:E / AndroidRuntime(9227):在android.app.Activity.onCreatePanelMenu(Activity.java:2444)
十二月一十号至2日:49:00.813:E / AndroidRuntime(9227):在android.support.v4.app.FragmentActivity.onCreatePanelMenu(FragmentActivity.java:224)
十二月一十号至2日:49:00.813:E / AndroidRuntime(9227):在android.support.v7.app.ActionBarActivity.superOnCreatePanelMenu(ActionBarActivity.java:224)
十二月一十号至2日:49:00.813:E / AndroidRuntime(9227):在android.support.v7.app.ActionBarActivityDelegateICS.onCreatePanelMenu(ActionBarActivityDelegateICS.java:141)
十二月一十号至2日:49:00.813:E / AndroidRuntime(9227):在android.support.v7.app.ActionBarActivity.onCreatePanelMenu(ActionBarActivity.java:199)
十二月一十号至2日:49:00.813:E / AndroidRuntime(9227):在android.support.v7.app.ActionBarActivityDelegateICS$WindowCallbackWrapper.onCreatePanelMenu(ActionBarActivityDelegateICS.java:280)
十二月一十号至2日:49:00.813:E / AndroidRuntime(9227):在com.android.internal.policy.impl.PhoneWindow preparePanel(PhoneWindow.java:392)
十二月一十号至2日:49:00.813:E / AndroidRuntime(9227):在com.android.internal.policy.impl.PhoneWindow.invalidatePanelMenu(PhoneWindow.java:743)
十二月一十号至2日:49:00.813:E / AndroidRuntime(9227):在com.android.internal.policy.impl.PhoneWindow $ 1.运行(PhoneWindow.java:2838)
十二月一十号至2日:49:00.813:E / AndroidRuntime(9227):在android.os.Handler.handleCallback(Handler.java:605)
十二月一十号至2日:49:00.813:E / AndroidRuntime(9227):在android.os.Handler.dispatchMessage(Handler.java:92)
十二月一十号至2日:49:00.813:E / AndroidRuntime(9227):在android.os.Looper.loop(Looper.java:137)
十二月一十号至2日:49:00.813:E / AndroidRuntime(9227):在android.app.ActivityThread.main(ActivityThread.java:4448)
十二月一十号至2日:49:00.813:E / AndroidRuntime(9227):在java.lang.reflect.Method.invokeNative(本机方法)
十二月一十号至2日:49:00.813:E / AndroidRuntime(9227):在java.lang.reflect.Method.invoke(Method.java:511)
十二月一十号至2日:49:00.813:E / AndroidRuntime(9227):在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run(ZygoteInit.java:823)
十二月一十号至2日:49:00.813:E / AndroidRuntime(9227):在com.android.internal.os.ZygoteInit.main(ZygoteInit.java:590)
十二月一十号至2日:49:00.813:E / AndroidRuntime(9227):在dalvik.system.NativeStart.main(本机方法)
我发现了错误。问题是,支持库,需要有一个自定义的preFIX而不是安卓actionProviderClass
。我在做什么错了,我用安卓actionProviderClass
而不是自定义preFIX:actionProviderClass
下面参见:<一href="https://developer.android.com/training/basics/actionbar/adding-buttons.html">https://developer.android.com/training/basics/actionbar/adding-buttons.html
Below is the code of my Activity . In this I am using the support library appcompat
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.view.MenuItemCompat;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.widget.ShareActionProvider;
import android.view.Menu;
import android.view.MenuItem;
public class MainActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
MenuItem item = (MenuItem) menu.findItem(R.id.share_options);
ShareActionProvider shareAction = (ShareActionProvider) MenuItemCompat
.getActionProvider(item);
Intent shareIntent = new Intent(Intent.ACTION_SEND)
.setAction(Intent.ACTION_SEND)
.putExtra(Intent.EXTRA_TEXT, "MobiTexter")
.setType("text/plain");
shareAction.setShareIntent(shareIntent);
return super.onCreateOptionsMenu(menu);
}
}
The following is my XML file for the menu options that is an ShareActionProvider Widget
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:mobitexter="http://schemas.android.com/apk/res-auto" >
<item
android:id="@+id/share_options"
android:actionProviderClass="android.support.v7.widget.ShareActionProvider"
android:orderInCategory="100"
mobitexter:showAsAction="never"
mobitexter:title="@string/share_options"/>
</menu>
In this i am getting an NullPointerException . Below is my log cat output.
10-02 12:49:00.813: E/AndroidRuntime(9227): FATAL EXCEPTION: main
10-02 12:49:00.813: E/AndroidRuntime(9227): java.lang.NullPointerException
10-02 12:49:00.813: E/AndroidRuntime(9227): at net.mobitexter.easyshare.MainActivity.onCreateOptionsMenu(MainActivity.java:31)
10-02 12:49:00.813: E/AndroidRuntime(9227): at android.app.Activity.onCreatePanelMenu(Activity.java:2444)
10-02 12:49:00.813: E/AndroidRuntime(9227): at android.support.v4.app.FragmentActivity.onCreatePanelMenu(FragmentActivity.java:224)
10-02 12:49:00.813: E/AndroidRuntime(9227): at android.support.v7.app.ActionBarActivity.superOnCreatePanelMenu(ActionBarActivity.java:224)
10-02 12:49:00.813: E/AndroidRuntime(9227): at android.support.v7.app.ActionBarActivityDelegateICS.onCreatePanelMenu(ActionBarActivityDelegateICS.java:141)
10-02 12:49:00.813: E/AndroidRuntime(9227): at android.support.v7.app.ActionBarActivity.onCreatePanelMenu(ActionBarActivity.java:199)
10-02 12:49:00.813: E/AndroidRuntime(9227): at android.support.v7.app.ActionBarActivityDelegateICS$WindowCallbackWrapper.onCreatePanelMenu(ActionBarActivityDelegateICS.java:280)
10-02 12:49:00.813: E/AndroidRuntime(9227): at com.android.internal.policy.impl.PhoneWindow.preparePanel(PhoneWindow.java:392)
10-02 12:49:00.813: E/AndroidRuntime(9227): at com.android.internal.policy.impl.PhoneWindow.invalidatePanelMenu(PhoneWindow.java:743)
10-02 12:49:00.813: E/AndroidRuntime(9227): at com.android.internal.policy.impl.PhoneWindow$1.run(PhoneWindow.java:2838)
10-02 12:49:00.813: E/AndroidRuntime(9227): at android.os.Handler.handleCallback(Handler.java:605)
10-02 12:49:00.813: E/AndroidRuntime(9227): at android.os.Handler.dispatchMessage(Handler.java:92)
10-02 12:49:00.813: E/AndroidRuntime(9227): at android.os.Looper.loop(Looper.java:137)
10-02 12:49:00.813: E/AndroidRuntime(9227): at android.app.ActivityThread.main(ActivityThread.java:4448)
10-02 12:49:00.813: E/AndroidRuntime(9227): at java.lang.reflect.Method.invokeNative(Native Method)
10-02 12:49:00.813: E/AndroidRuntime(9227): at java.lang.reflect.Method.invoke(Method.java:511)
10-02 12:49:00.813: E/AndroidRuntime(9227): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:823)
10-02 12:49:00.813: E/AndroidRuntime(9227): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:590)
10-02 12:49:00.813: E/AndroidRuntime(9227): at dalvik.system.NativeStart.main(Native Method)
I found the error. The problem was that support library requires to have a custom prefix and not android:actionProviderClass
. What i was doing wrong that i used android:actionProviderClass
instead of customprefix:actionProviderClass
See here: https://developer.android.com/training/basics/actionbar/adding-buttons.html
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