Question

大家好我需要将arraylist从活动传递到自定义适配器类但是我的代码没有通过...我不知道为什么！

我使用意图来传递数据：

活动：

private void azz() {
    int a=0;
    String status="";
    boolean statuss = false;
    String intenttt= path;

    System.out.println("INTENT:"+intenttt);



    file = new File(intenttt);
    System.out.println("FILE:"+file);

    FileInputStream is = null;
    try {
        is = new FileInputStream(file);
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }

    DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
    DocumentBuilder dBuilder = null;
    try {
        dBuilder = dbFactory.newDocumentBuilder();
    } catch (ParserConfigurationException e) {
        e.printStackTrace();
    }
    Document doc = null;
    try {
        doc = dBuilder.parse(is);
    } catch (SAXException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

    Element element = doc.getDocumentElement();
    element.normalize();

    NodeList nList = doc.getElementsByTagName("checkboxes_pizza");

    for (int i = 0; i < nList.getLength(); i++) {
        Node node = nList.item(i);
        if (node.getNodeType() == Node.ELEMENT_NODE) {
            Element element2 = (Element) node;
            //tv1.setText(tv1.getText()+"\nName : " + getValue("name", element2)+"\n");
            String id = getValue("id", element2);
            a = Integer.parseInt(id);
            status = getValue("status", element2);

            statuss= Boolean.parseBoolean(status);

            System.out.println("XML:" + a);

            hm.add(a);

            System.out.println("AZZ:" + hm);





        }

    }

    Intent intent = new Intent(ScrollableTabsActivity.this,PlanetAdapter.class) ;
    intent.putIntegerArrayListExtra("a", hm);
    startActivity(intent);


     // ok();


}

获得意向的自定义适应器：

 Intent intent = getIntent();
        Arraylist<Integer> email=intent.getIntegerArrayListExtra("a");

而且getIntent（）由IDE写成红色......

Answer 1

这是因为getIntent()在适配器类中不可用，除非您在其中声明了一个名为getIntent()的函数。在适配器中添加一个函数以接收适配器中的数据，并调用notifyDataSetChanged()刷新列表。例如：

class DataAdapter extends ArrayAdapter<String> {

    private ArrayList<String> items = new ArrayList<>();

    public DataAdapter(@NonNull Context context, @LayoutRes int resource) {
        super(context, resource);
    }


    public void setItems(ArrayList<String> items) {
        this.items = items;
        notifyDataSetChanged();
    }
    //some more code
}

在您的活动中

创建适配器的实例并将其绑定到list / spinner，然后调用该函数以在适配器中添加数据。

Answer 2

要传递数组，我建议在适配器中创建一个静态数组变量，如下所示： Arraylist<Integer> variable
然后通过使用传递值 adapterFileName.variable = hm（其中hm是一个arrayList，因为它在您开始活动之前的活动中就是这样称呼它。）

Answer 3

  // In activity pass Data to Your adapter like DefaulterAdapter 
  // (mContext,modelDefulterLists,schemeId1)

  class DefaulterAdapter extends BaseAdapter
  {

   //init here your data
   String schemeId1;
   Context mContext;
   ArrayList<ModelDefulterList> modelDefulterLists;

    // in adapter i get data from custructer 
    public DefaulterAdapter(Context mContext, ArrayList<String> 
    modelDefulterLists, String schemeId1)
    {
      this.mContext = mContext;
      this.modelDefulterLists = modelDefulterLists;
      prefsHelper = new PrefsHelper(mContext);
     this.schemeId1 = schemeId1;
    }
 }

如何将数据从活动传递到自定义适配器

3 个答案: