Question

我需要从ListActivity中显示类别的列表。我的数据源是Category类型的ArrayList，它实现了android Parcelable接口。结构在底部给出。它有一个id和一个标题

我需要将标题显示为列表文本，单击列表项时，我需要获取进一步处理的ID

可以通过迭代类别ArrayList并使用来创建一个新的'title'数组 this.setListAdapter(new ArrayAdapter<String>(this, R.layout.rowlayout, R.id.label, names));

但是使用这种方法我只会在点击时获得该类别的标题，而不是id。

是否可以直接使用对象的ArrayList作为数据源？

public class CategoryList extends ListActivity  {
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        Intent t = new Intent(this, ParsingWebXML.class);
        startActivityForResult(t,1);
    }

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if(requestCode == 1 && resultCode == RESULT_CANCELED){
            finish();
        } else {
            createCategoryList(data);
        }
    }

    private void createCategoryList(Intent data) {
        ArrayList<Category> categories = null;
        try {
            categories = data.getParcelableArrayListExtra("categoryList");
            Iterator<Category> itr = categories.iterator();

            String[] names = new String[categories.size()];
            int i=0;
            while (itr.hasNext()) {
                Category c = itr.next();
                names[i++] = c.getTitle();
            }
            this.setListAdapter(new ArrayAdapter<Category>(this, R.layout.rowlayout, R.id.label, categories));
            // String[] names = new String[] { "Sports", "Mediacal", "Computers" };
            // this.setListAdapter(new ArrayAdapter<String>(this, R.layout.rowlayout, R.id.label, names));
        } catch (Exception e) {
            // TODO: handle exception
        }
    }

    @Override
    protected void onListItemClick(ListView l, View v, int position, long id) {
        super.onListItemClick(l, v, position, id);

        // Get the item that was clicked
        Object o = this.getListAdapter().getItem(position);
        String keyword = o.toString();

        if(keyword=="Categories"){
            Intent cat = new Intent(this, CategoryActivity.class);
            startActivity(cat);
            //Toast.makeText(this, keyword, Toast.LENGTH_LONG).show();
        } else {
            Intent cat = new Intent(this, CategoryActivity.class);
            startActivity(cat);
        }

    }

}

Category.java

public class Category implements Parcelable {

    private int id;
    private String title;

    public Category() {

    }

    public Category(Parcel source) {
        id = source.readInt();
        title = source.readString();
    }

    public void setId(int id) {
        this.id = id;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public int getId() {
        return this.id;
    }

    public String getTitle() {
        return this.title;
    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
          dest.writeInt(id);
          dest.writeString(title);
    }

    public static final Parcelable.Creator CREATOR = new Parcelable.Creator() {

        @Override
        public Category createFromParcel(Parcel source) {
            return new Category(source);
        }

        @Override
        public Category[] newArray(int size) {
            return new Category[size];
            // TODO Auto-generated method stub
        }

    };

}

Answer 1

扩展ArrayAdapter<T>并扩展它的getView()方法。让它返回您选择的视图。

然后将其用作MyArrayAdapter<Category>。

Answer 2

以下是如何进行ArrayAdapter类的自定义实现的两个很好的示例：

使用ArrayList of Objects作为布局资源的Android ListActivity

2 个答案: