Question

我想更新在ui线程上运行的listview适配器。

这是我的代码：

  @Override
   public void addItem(final String data) {
           runOnUiThread(new Runnable() {
               @Override
               public void run() {                  
                   list.setAdapter(new ListAdapter(MainActivity.this, data, width, height));


               }
           });  

    }

现在我的问题是这段代码总是引发异常，实际上我并不知道为什么或是什么原因导致例外......

以下是例外情况：

12-17 14:48:13.241: E/AndroidRuntime(26289): FATAL EXCEPTION: main
12-17 14:48:13.241: E/AndroidRuntime(26289): java.lang.NullPointerException
12-17 14:48:13.241: E/AndroidRuntime(26289):    at      android.widget.ListView.setupChild(ListView.java:1797)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.widget.ListView.makeAndAddView(ListView.java:1775)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.widget.ListView.fillDown(ListView.java:672)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.widget.ListView.fillFromTop(ListView.java:732)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.widget.ListView.layoutChildren(ListView.java:1625)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.widget.AbsListView.onLayout(AbsListView.java:1863)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.view.View.layout(View.java:11282)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.view.ViewGroup.layout(ViewGroup.java:4224)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.widget.RelativeLayout.onLayout(RelativeLayout.java:925)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.view.View.layout(View.java:11282)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.view.ViewGroup.layout(ViewGroup.java:4224)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.widget.RelativeLayout.onLayout(RelativeLayout.java:925)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.view.View.layout(View.java:11282)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.view.ViewGroup.layout(ViewGroup.java:4224)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.widget.FrameLayout.onLayout(FrameLayout.java:431)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.view.View.layout(View.java:11282)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.view.ViewGroup.layout(ViewGroup.java:4224)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1628)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1486)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.widget.LinearLayout.onLayout(LinearLayout.java:1399)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.view.View.layout(View.java:11282)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.view.ViewGroup.layout(ViewGroup.java:4224)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.widget.FrameLayout.onLayout(FrameLayout.java:431)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.view.View.layout(View.java:11282)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.view.ViewGroup.layout(ViewGroup.java:4224)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1514)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.view.ViewRootImpl.handleMessage(ViewRootImpl.java:2467)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.os.Handler.dispatchMessage(Handler.java:99)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.os.Looper.loop(Looper.java:137)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at android.app.ActivityThread.main(ActivityThread.java:4424)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at java.lang.reflect.Method.invokeNative(Native Method)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at java.lang.reflect.Method.invoke(Method.java:511)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
12-17 14:48:13.241: E/AndroidRuntime(26289):    at dalvik.system.NativeStart.main(Native Method)

Answer 1

我认为你的适配器的getView（）是问题

 @Override
public View getView(final int position, View convertView, ViewGroup parent) {


    View view = convertView;
    if (view == null) {
        if (tf == null) {
            tf = new FontsProperties(parent.getContext()).getNormalFont();
        }
        LayoutInflater inflater = LayoutInflater.from(parent.getContext());
        view = inflater.inflate(R.layout.aminities_item, parent, false);
        ChildHolder holder = new ChildHolder();
        holder.chkBox = (CheckBox) view.findViewById(R.id.chkBox);

        view.setTag(holder);
    }
    ChildHolder holder = (ChildHolder) view.getTag();
    holder.txtTitle.setText(items.get(position).getItem().getText(parent.getContext()));
    holder.chkBox.setChecked(items.get(position).isSelected());

    holder.linParent.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            items.get(position).setSelected(!items.get(position).isSelected());
            notifyDataSetChanged();
        }
    });

    return view;

在ui线程方法上运行更新listview适配器

1 个答案: