Android如果在ViewHolder中声明

我在Android中使用BaseAdapter。这些是我的代码。Android如果在ViewHolder中声明

public View getView(int position, View convertView, ViewGroup parent) { 
     ViewHolder holder; 
     if (convertView == null) { 
      convertView = layoutInflater.inflate(R.layout.article_list_item, null); 
      holder = new ViewHolder(); 
      holder.favoriteImage= (ImageView) convertView.findViewById(R.id.imageViewFavoriteItem); 
      convertView.setTag(holder); 
     } else { 
      holder = (ViewHolder) convertView.getTag(); 
     } 
     ArticleItem articleItem = (ArticleItem) listData.get(position); 
     String isFavorite= articleItem.get_favorite(); 
     if(isFavorite.equals("1")) 
     { 
      holder.favoriteImage.setImageResource(R.drawable.ic_star_active); 
     } 

     return convertView; 
    }

问题是我有一个项目列表，我想添加“星形图标”到添加到收藏夹的项目。

 String isFavorite= articleItem.get_favorite(); 
     if(isFavorite.equals("1")) 
     { 
      //Statement is okay 
     }

但是我无法像这样使用它。

 String isFavorite= articleItem.get_favorite(); 
     if(isFavorite.equals("1")) 
     { 
      holder.favoriteImage.setImageResource(R.drawable.ic_star_active); 
     }

我做了一些研究，来到这。 Android BaseAdapter Context

an Activity is a single, focused thing that the user can do. Almost all activities interact with the user, so the Activity class takes care of creating a window for you in which you can place your UI. 
a Fragment is a piece of an application's user interface or behavior that can be placed in an Activity. 
an Adapter object acts as a bridge between an AdapterView and the underlying data for that view. It is also responsible for making a View for each item in the data set.

根据什么答案说我不能适配器使用。我不确定，因为我来自PHP背景。我现在卡住了。

这里是调试日志

09-03 02:22:36.278 1233-1233/myanmarwebsolutions.myanmar_shopper D/AndroidRuntime﹕ Shutting down VM 
09-03 02:22:36.278 1233-1233/myanmarwebsolutions.myanmar_shopper W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0xa6225288) 
09-03 02:22:36.278 1233-1233/myanmarwebsolutions.myanmar_shopper E/AndroidRuntime﹕ FATAL EXCEPTION: main 
    java.lang.NullPointerException 
      at myanmarwebsolutions.mws_myanmarshopper.Adatper.ArticleAdapter.getView(ArticleAdapter.java:92) 
      at android.widget.AbsListView.obtainView(AbsListView.java:2267) 
      at android.widget.ListView.measureHeightOfChildren(ListView.java:1244) 
      at android.widget.ListView.onMeasure(ListView.java:1156) 
      at android.view.View.measure(View.java:15172) 
      at android.widget.RelativeLayout.measureChild(RelativeLayout.java:602) 
      at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:415) 
      at android.view.View.measure(View.java:15172) 
      at android.widget.LinearLayout.measureVertical(LinearLayout.java:833) 
      at android.widget.LinearLayout.onMeasure(LinearLayout.java:574) 
      at android.view.View.measure(View.java:15172) 
      at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4814) 
      at android.widget.FrameLayout.onMeasure(FrameLayout.java:310) 
      at android.view.View.measure(View.java:15172) 
      at android.widget.LinearLayout.measureVertical(LinearLayout.java:833) 
      at android.widget.LinearLayout.onMeasure(LinearLayout.java:574) 
      at android.view.View.measure(View.java:15172) 
      at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4814) 
      at android.widget.FrameLayout.onMeasure(FrameLayout.java:310) 
      at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2148) 
      at android.view.View.measure(View.java:15172) 
      at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1848) 
      at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1100) 
      at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1273) 
      at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:998) 
      at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4212) 
      at android.view.Choreographer$CallbackRecord.run(Choreographer.java:725) 
      at android.view.Choreographer.doCallbacks(Choreographer.java:555) 
      at android.view.Choreographer.doFrame(Choreographer.java:525) 
      at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:711) 
      at android.os.Handler.handleCallback(Handler.java:615) 
      at android.os.Handler.dispatchMessage(Handler.java:92) 
      at android.os.Looper.loop(Looper.java:137) 
      at android.app.ActivityThread.main(ActivityThread.java:4745) 
      at java.lang.reflect.Method.invokeNative(Native Method) 
      at java.lang.reflect.Method.invoke(Method.java:511) 
      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786) 
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
      at dalvik.system.NativeStart.main(Native Method) 
09-03 02:22:36.294 1233-1236/myanmarwebsolutions.myanmar_shopper D/dalvikvm﹕ GC_CONCURRENT freed 1276K, 12% free 10991K/12359K, paused 11ms+1ms, total 16ms 
09-03 02:22:36.646 1233-1272/myanmarwebsolutions.myanmar_shopper D/skia﹕ --- SkImageDecoder::Factory returned null 
09-03 02:22:36.646 1233-1272/myanmarwebsolutions.myanmar_shopper D/skia﹕ --- SkImageDecoder::Factory returned null 
09-03 02:22:37.446 1233-1263/myanmarwebsolutions.myanmar_shopper D/skia﹕ --- SkImageDecoder::Factory returned null 
09-03 02:22:37.446 1233-1263/myanmarwebsolutions.myanmar_shopper D/skia﹕ --- SkImageDecoder::Factory returned null

来源

2014-09-03 Myanmar Web Solution

你能解释这条线不能正常工作，应该表现出了图像holder.favoriteImage.setImageResource（R.drawable.ic_star_active）的问题; – 2014-09-03 01:57:21

我可以使用“holder.favoriteImage.setImageResource（R.drawable.ic_star_active）;”但不能放入“if”语句 – 2014-09-03 02:02:01

里面发生了什么if语句是否显示在另一个位置解释了这个问题？ – 2014-09-03 02:03:11

你需要写else语句也东阳适配器重用这是已经创建所以，如果和别人都应该有

设置喜欢的图像中的旧观点否则ALSE

来源

2014-09-03 02:05:52

加入其他不工作 “ 字符串isFavorite = articleItem.get_favorite（）;如果（isFavorite.equals（” 1" ）） { holder.favoriteImage.setImageResource（R.drawable.ic_star_active）; } else { holder.favoriteImage.setImageResource（R.drawable.ic_star_inactive）; }“ – 2014-09-03 02:15:58

Android如果在ViewHolder中声明

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