Question

此行抛出空指针异常错误：

String dataPath = intent.getData().toString();

有谁知道为什么？以下是我主要活动的片段。一切都很好看。

   protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_contact_picker);
    Intent intent = getIntent();

    String dataPath = intent.getData().toString();
    final Uri data = Uri.parse(dataPath+"people/");
    final Cursor c = managedQuery(data, null, null, null, null);

    String[] from = new String[] {People.NAME};
    int[] to = new int[]  {R.id.itemTextView };

     SimpleCursorAdapter adapter = new SimpleCursorAdapter(this,                                   
    R. layout.listitemlayout, c, from, to);
    ListView lv = (ListView)findViewById(R.id.contactListView);
    lv.setAdapter(adapter);
    lv.setOnItemClickListener(new OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View view, int pos,
                long id) {
            c.moveToPosition(pos);
            int rowId = c.getInt(c.getColumnIndexOrThrow("_id"));

            Uri outURI = Uri.parse(data.toString() + rowId);
            Intent outData = new Intent();
            outData.setData(outURI);
            setResult(Activity.RESULT_OK, outData);
            finish();
        }

    });
   }

Answer 1

要调用其他活动，我们通常会使用这样的意图：

要发送的第一个活动：

Intent in = new Intent(MainActivity.this, NewActivity.class);   
String StrName = "xyz"
in.putExtra("data",StrName);
startActivity (in);

接收另一项活动：

String Sname = getIntent().getExtras().getString("data");

要查看意图的详细信息，请参阅此处：http://developer.android.com/guide/components/intents-filters.html

运行期间出现空指针异常错误

1 个答案: