Question

我在我的Android应用程序中使用了列表视图，我使用字符串数组值填充它，它工作正常！但是，当我尝试使用JSON内容时，使用类，使用名称和代码作为类中的数据成员。这是我的代码：

 private void fillListView() {

    ListView mainListView;
    ArrayAdapter<String> listAdapter;
    ArrayAdapter<Planets> listPlanetsClassAdapter;
    mainListView = (ListView) findViewById(R.id.lst_Details);
    String[] planets = new String[]{"Mercury", "Venus", "Earth", "Mars",
            "Jupiter", "Saturn", "Uranus", "Neptune"};
    String[] planets1 = new String[]{"Mercury", "Venus", "Earth", "Mars",
            "Jupiter", "Saturn", "Uranus", "Neptune"};
    ArrayList<String> planetList = new ArrayList<String>();
    ArrayList<Planets> planetLISTJSON= new ArrayList<Planets>();
    Planets obj_Planets = new Planets();
    planetList.addAll(Arrays.asList(planets));

    // JSONArray jsonArray = new JSONArray(Arrays.asList(planets));
    for ( int i=0;i<planets1.length;++i)
    {
        obj_Planets.code=12;
        obj_Planets.name="My Gola";//planets1[i];
        planetLISTJSON.add(obj_Planets);
    }

    // into the ArrayAdapter constructor, you must not add more items.
    // Otherwise an exception will occur.
    listAdapter.add("Ceres");
    listAdapter.add("Pluto");
    listAdapter.add("Haumea");
    listAdapter.add("Makemake");
    listAdapter.add("Eris");
    //mainListView.deferNotifyDataSetChanged();
    // Set the ArrayAdapter as the ListView's adapter.
    mainListView.setAdapter(listPlanetsClassAdapter);
}

public class Planets {
   public String name;
   public int code;
}

Answer 1

创建一个自定义适配器，扩展public class MainActivity extends AppCompatActivity { private TextView display; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); findPath(); } private void findPath() { TextView txtMatrixDisplay = (TextView) findViewById(R.id.textView_display); // 1st example int[][] matrix1 = new int[][]{ { 3, 4, 1, 2, 8, 6 }, { 6, 1, 8, 2, 7, 4 }, { 5, 9, 3, 9, 9, 5 }, { 8, 4, 1, 3, 2, 6 }, { 3, 7, 2, 8, 6, 4 } }; String txtMatrix1 = ""; for(int i=0; i<matrix1.length; i++){ for(int j=0; j<matrix1[0].length; j++){ txtMatrix1 += matrix1[i][j] + " "; } txtMatrix1 += "\n"; } txtMatrixDisplay.setText(txtMatrix1); Solution firstExample = new Solution(); firstExample.Path(matrix1); String result1 = "\n"; if(firstExample.getStat()){ result1 += "Yes\n"; } else { result1 += "No\n"; } result1 += firstExample.getCost() + "\n"; result1 += firstExample.getPath() + "\n"; txtMatrixDisplay.append(result1); // 2nd example int[][] matrix2 = new int[][]{ {3, 4, 1, 2, 8, 6 }, {6, 1, 8, 2, 7, 4 }, {5, 9, 3, 9, 9, 5 }, {8, 4, 1, 3, 2, 6 }, {3, 7, 2, 1, 2, 3 } }; String txtMatrix2 = "\n"; for(int i=0; i<matrix2.length; i++){ for(int j=0; j<matrix2[0].length; j++){ txtMatrix2 += matrix2[i][j] + " "; } txtMatrix2 += "\n"; } txtMatrixDisplay.append(txtMatrix2); Solution secondExample = new Solution(); secondExample.Path(matrix2); String result2 = "\n"; if(secondExample.getStat()){ result2 += "Yes\n"; } else { result2 += "No\n"; } result2 += secondExample.getCost() + "\n"; result2 += secondExample.getPath() + "\n"; txtMatrixDisplay.append(result2); // 1st example int[][] matrix3 = new int[][]{ {19, 10, 19, 10, 19 }, {21, 23, 20, 19, 12 }, {20, 12, 20, 11, 10 } }; String txtMatrix3 = "\n"; for(int i=0; i<matrix3.length; i++){ for(int j=0; j<matrix3[0].length; j++){ txtMatrix3 += matrix3[i][j] + " "; } txtMatrix3 += "\n"; } txtMatrixDisplay.append(txtMatrix3); Solution thirdExample = new Solution(); thirdExample.Path(matrix3); String result3 = "\n"; if(thirdExample.getStat()){ result3 += "Yes\n"; } else { result3 += "No\n"; } result3 += thirdExample.getCost() + "\n"; result3 += thirdExample.getPath(); txtMatrixDisplay.append(result3); } }并覆盖方法ArrayAdapter，以返回包含您要显示的内容的自己的视图。

例如，

<强> UserAdapter.class

getView()

使用自定义适配器

public class UsersAdapter extends ArrayAdapter<User> {
    public UsersAdapter(Context context, ArrayList<User> users) {
       super(context, 0, users);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
       // Get the data item for this position
       User user = getItem(position);    
       // Check if an existing view is being reused, otherwise inflate the view
       if (convertView == null) {
          convertView = LayoutInflater.from(getContext()).inflate(R.layout.item_user, parent, false);
       }
       // Lookup view for data population
       TextView tvName = (TextView) convertView.findViewById(R.id.tvName);
       TextView tvHome = (TextView) convertView.findViewById(R.id.tvHome);
       // Populate the data into the template view using the data object
       tvName.setText(user.name);
       tvHome.setText(user.hometown);
       // Return the completed view to render on screen
       return convertView;
   }
}

您可以查看更多详情here

将JSON设置为Android应用中

1 个答案: