如何编写 ArrayList 适配器？ [复制]

Question

我想将 arrayList 的字段转换为 listView，但我不知道如何编写适配器。请帮帮我！！！

我需要一个适配器类。我必须在 listView tutar 上看到：1.34 kalem="xx"

类：

public class Income {





String kalem;
int tutar;

public int getTutar() {
    return tutar;
}
public void setTutar(int tutar) {
    this.tutar = tutar;
}
int id;
public int getId() {
    return id;
}
public void setId(int id) {
    this.id = id;
}

public String getKalem() {
    return kalem;
}
public void setKalem(String kalem) {
    this.kalem = kalem;
}

}

数组列表：

sqliteHelper helper = new sqliteHelper(getApplicationContext());
    ArrayList<Income> liste=helper.getAllIncome();

Answer 1

您可以通过两种方式构建适配器：--

使用Android系统提供的一些适配器，例如：-

 SimpleCursorAdapter
 ArrayAdapter,etc

例子：--

 ListView listView = (ListView) findViewById(R.id.<list_view_id>);
 ArrayList<Income> income_array_list = <get the arraylist from whatever sources>;
 ArrayAdapter<Income> arrayAdapter = new ArrayAdapter<Income>(
         this, 
         android.R.layout.simple_list_item_1,
         income_array_list );

 listView.setAdapter(arrayAdapter); 

创建您自己的自定义适配器。

我只使用了两个字段，只是为了向您展示如何构建自定义适配器，其余您可以通过查看此代码来构建。

例子：-

IncomeListAdapter 类

private class IncomeListAdapter extends BaseAdapter {

    ArrayList<Income> mDisplayedValues;
    LayoutInflater inflater;

    public IncomeListAdapter(Context context) {
        // TODO Auto-generated constructor stub
        mDisplayedValues = <your_Income_list>;
        inflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return mDisplayedValues.size();
    }

    @Override
    public Object getItem(int arg0) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public View getView(final int position, View convertView,
            ViewGroup parent) {
        // TODO Auto-generated method stub

        View v = convertView;
        ViewHolder holder;
        if (v == null) {
            v = inflater.inflate(R.layout.listrow_income, null);
            holder = new ViewHolder();
            holder.tvTutar = (TextView) v
                    .findViewById(R.id.tvTutar);
            holder.tvId = (TextView) v.findViewById(R.id.tvId);

            v.setTag(holder);
        } else
            holder = (ViewHolder) v.getTag();
               holder.tvTutar.setText(mDisplayedValues.get(position).getTutar());
           holder.tvId.setText(mDisplayedValues.get(position).getId());
           return v;
    }

    class ViewHolder {
        TextView tvTutar;
        TextView tvId;
    }
}

listrow_income.xml:--

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="?android:attr/listPreferredItemHeight"
android:gravity="center"
android:orientation="horizontal"
android:padding="8dp" >
   <TextView
    android:id="@+id/tvTutar"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textColor="#323232" />
   <TextView
    android:id="@+id/tvId"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textColor="@android:color/white"    />

 </LinearLayout>

Answer 2

试试这个

private ListView lv;

public void onCreate(Bundle saveInstanceState) {
     setContentView(R.layout.your_layout);

     lv = (ListView) findViewById(R.id.your_list_view_id);

     // Instanciating an array list (you don't need to do this, 
     // you already have yours).
     sqliteHelper helper = new sqliteHelper(getApplicationContext());
     ArrayList<Income> your_array_list = helper.getAllIncome();

     // This is the array adapter, it takes the context of the activity as a 
     // first parameter, the type of list view as a second parameter and your 
     // array as a third parameter.
     ArrayAdapter<Income> arrayAdapter = new ArrayAdapter<Income>(
             this, 
             android.R.layout.simple_list_item_1,
             your_array_list );

     lv.setAdapter(arrayAdapter); 
}