多列列表中的nullPointerException

时间:2011-12-06 05:29:30

标签: android listview tablelayout illegalstateexception

我已经在SO上尝试过类似问题的引用,但是没有得到合适的解决方案。

我正在尝试从网页中获取数据,并以包含4列的行的格式显示。

网页上显示的数据:

SBIN ;1916.00;1886.85;1.54@LT ;1315.50;1310.30;0.40@TCS ;1180.00;1178.00;0.17@AXISBANK ;1031.30;1005.95;2.52@MARUTI ;1000.35;992.35;0.81@PNB ;931.90;916.35;1.70@GAIL ;400.00;398.45;0.39@

我想以

的形式透露它
SBIN.........1916.00.....1886.85.....1.54

LT...........1315.50.....1310.30.....0.40  and so on. 

请注意,我不想要点,我希望每个值都是一行中的单独列。

我的数据包含7行。

当我运行以下代码时,我得到此输出Screenshot 即。

 values[0]   values[1]   values[2]   values[3]

 values[1]   values[2]   values[3]   values[4]

 values[2]   values[3]   values[4]   values[5]

(打印第1行的所有4个col,然后是第1行的第2-4列和第2行的col1,然后是第1行的3-4和第2行的第1-2行,依此类推......)

ReadWebpageAsyncTask.java

public class ReadWebpageAsyncTask extends Activity {
    private EditText ed;
    private ListView lv;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        ed = (EditText) findViewById(R.id.ed);
        lv = (ListView) findViewById(R.id.list);
        DownloadWebPageTask task = new DownloadWebPageTask();
        task.execute(new String[] { "http://abc.com/default.aspx?id=G" });
    }

    private class DownloadWebPageTask extends AsyncTask<String, Void, String> {
        @Override
        protected String doInBackground(String... urls) {
            String response = "";
            for (String url : urls) {
                DefaultHttpClient client = new DefaultHttpClient();
                HttpGet httpGet = new HttpGet(url);
                try {
                    HttpResponse execute = client.execute(httpGet);
                    InputStream content = execute.getEntity().getContent();

                    BufferedReader buffer = new BufferedReader(
                            new InputStreamReader(content));
                    String s = "";
                    while ((s = buffer.readLine()) != null) {
                        response += s;
                    }

                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
            return response;
        }

        @Override
        protected void onPostExecute(String result) {
            int sub = result.lastIndexOf('@', result.length() - 1);
            String s1 = result.substring(0, sub + 2);
            String temp[];
            String subarr[] = new String[100];
            ;
            Log.v("data = ", s1);
            // String s = s1.replace(";", " - ");
            final String arr[] = s1.split("@");

            for (int i = 0; i < arr.length; i++) {
                Log.v("arr" + i, arr[i] + "    " + arr.length);
            }

            for (int i = 0; i < arr.length - 1; i++)

            {
                temp = arr[i].split(";");
                subarr[(4 * i)] = temp[0];
                subarr[(4 * i) + 1] = temp[1];
                subarr[(4 * i) + 2] = temp[2];
                subarr[(4 * i) + 3] = temp[3];
                        }
        lv.setAdapter(new MyAdapter(ReadWebpageAsyncTask.this, subarr));
        }
    }
}

main.xml中

            <?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    <EditText android:id="@+id/ed" 
        android:layout_width="match_parent" 
        android:layout_height="wrap_content" 
        android:hint="Search">
    </EditText>

    <ListView android:id="@+id/list"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">
    </ListView>

    </LinearLayout>

MyAdapter.java

   public class MyAdapter extends ArrayAdapter<String> {
    private final Context context;
    private final String[] values;

    private String item1, item2, item3, item0;
    int x = 0, i = 1, y = 1;

    public MyAdapter(Context context, String[] values) {
        super(context, R.layout.row, values);
        this.context = context;
        this.values = values;
    }

    @Override
    public String getItem(int position) {
        return values[position];
    }

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

        LayoutInflater inflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View rowView = inflater.inflate(R.layout.row, parent, false);
        TextView tv1 = (TextView) rowView.findViewById(R.id.col1);
        TextView tv2 = (TextView) rowView.findViewById(R.id.col2);
        TextView tv3 = (TextView) rowView.findViewById(R.id.col3);
        TextView tv4 = (TextView) rowView.findViewById(R.id.col4);

        if (y < 8) {
            item0 = getItem(position);
            Log.v("pos = ", "" + position);
            item1 = getItem(position + 1);
            item2 = getItem(position + 2);
            item3 = getItem(position + 3);

            tv1.setText(item0);
            tv2.setText(item1);
            tv3.setText(item2);
            tv4.setText(item3);

        } else {
            Log.v("y= ", "" + y);
        }
        return rowView;
    }
}

row.xml

    <?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal" >

             <TextView android:id="@+id/col1"
             android:layout_width="150dip"
             android:layout_height="wrap_content"/>

             <TextView android:id="@+id/col2"
             android:layout_width="70dip"
             android:layout_height="wrap_content"/>

              <TextView android:id="@+id/col3"
             android:layout_width="70dip"
             android:layout_height="wrap_content"/>

              <TextView android:id="@+id/col4"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"/>

    </LinearLayout>

任何帮助实现

3 个答案:

答案 0 :(得分:2)

尝试使用ListView

而不是TableLayout将ListView添加到xml中,并将内容放在新xml中的表中 通过扩展ArrayAdapter创建适配器,并在listView上设置此适配器。

答案 1 :(得分:0)

不要在Java代码中添加视图,因为它们是根据您的XML文件添加的。在我看来,你的Java代码重复了你在XML中做的非常不稳定的事情......

我不明白为什么你不能只删除Java代码并使用setContentView来使用你定义的XML布局。

答案 2 :(得分:0)

将宽度设置为0,并为所有测试视图添加权重1,它将为行中的每个项目均匀分配空间。

    textView1.setWidth(0);
    textView1.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT, 1f));