如何使用Retrofit2在Listview中显示json数据

Question

我是关于Android编程的新手:(

我不知道为显示数据设置Listview如何在Listview中显示数据。

MainActivity.java

public class MainActivity extends AppCompatActivity {


  private static final String TAG = "fong";
  ListView listView;


  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


    listView = (ListView) findViewById(R.id.listView);

    Retrofit retrofit = new Retrofit.Builder()
              .baseUrl(UdacityService.BASE_URL)
              .addConverterFactory(GsonConverterFactory.create())
              .build();

    UdacityService service = retrofit.create(UdacityService.class);
    Call<UdacityCatalog> requestCatalog = service.listCatalog();

    requestCatalog.enqueue(new Callback<UdacityCatalog>() {
      @Override
      public void onResponse(Call<UdacityCatalog> call, Response<UdacityCatalog> response) {
        if (!response.isSuccessful()) {

          Log.i(TAG,"Errorr: " +response.code());
        }else{
          UdacityCatalog catalog =response.body();


          for (Course c : catalog.courses){
            Log.i(TAG,c.title);

            Log.i(TAG,"--------------");

          }
        }
      }

      @Override
      public void onFailure(Call<UdacityCatalog> call, Throwable t) {
        Log.e(TAG,"Errorr: " + t.getMessage());
      }
    });

  }
}

我想在ListView中显示数据c.title

Log.i(TAG,c.title)显示

I/fong: Richard Kalehoff

I/fong: Firebase Analytics: iOS

I/fong: Firebase Analytics: Android

感谢您的帮助:)

Answer 1

很简单，首先您必须在Layout中添加一个ListView组件：

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

然后，在您的JAVA代码中找到它并将其放在实例变量中：

ListView listview;

    //in your onCreate() after setContentView():
    listview = (ListView) findViewById(R.id.list);

您必须创建一个包含所有标题的列表：

List<String> courses = new ArrayList<>();
  for (Course c : catalog.courses){
          courses.add(c.title);
          }

现在，您必须创建一个SimpleAdapter并将数据传递给它：

ArrayAdapter adapter = new ArrayAdapter(MainActivity.this, android.r.layout.simple_list_item_1, courses);

最后，在您的ListView添加适配器：

listview.setAdapter(adapter);

Answer 2

选课程清单

List<Course> courseList = catalog.courses;

然后创建一个自定义列表适配器，并从该列表中获取标题并将其显示在列表的textView中

textView.setText(courseList.get(position).title);