HashMap到ListView

Question

我有HashMap，我該如何把它放在ListView中？哪個適配器需要使用？

public void showCinemas(HashMap<String, String> cinemas) 
{ 
    ...//What? 
    list.setAdapter(adapter); 
} 

Answer 1

進行簡單的適配器類：

MyAdapter.java

import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.BaseAdapter; 
import android.widget.TextView; 

import java.util.ArrayList; 
import java.util.Map; 

public class MyAdapter extends BaseAdapter { 
    private final ArrayList mData; 

    public MyAdapter(Map<String, String> map) { 
     mData = new ArrayList(); 
     mData.addAll(map.entrySet()); 
    } 

    @Override 
    public int getCount() { 
     return mData.size(); 
    } 

    @Override 
    public Map.Entry<String, String> getItem(int position) { 
     return (Map.Entry) mData.get(position); 
    } 

    @Override 
    public long getItemId(int position) { 
     // TODO implement you own logic with ID 
     return 0; 
    } 

    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 
     final View result; 

     if (convertView == null) { 
      result = LayoutInflater.from(parent.getContext()).inflate(R.layout.my_adapter_item, parent, false); 
     } else { 
      result = convertView; 
     } 

     Map.Entry<String, String> item = getItem(position); 

     // TODO replace findViewById by ViewHolder 
     ((TextView) result.findViewById(android.R.id.text1)).setText(item.getKey()); 
     ((TextView) result.findViewById(android.R.id.text2)).setText(item.getValue()); 

     return result; 
    } 
} 

佈局/ my_adapter_item.xml

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout 
     xmlns:android="http://schemas.android.com/apk/res/android" 
     android:orientation="vertical" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     > 

    <TextView 
      android:id="@android:id/text1" 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      /> 

    <TextView 
      android:id="@android:id/text2" 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      /> 
</LinearLayout> 

您的代碼：

public void showCinemas(HashMap<String, String> cinemas) { 
    MyAdapter adapter = new MyAdapter(cinemas); 
    list.setAdapter(adapter); 
} 

Answer 2

其公允簡單：

你要創建，爲例如列表項。說你必須把學生的記錄，如姓名列表中的項目和解決

private HashMap<String,Object> prepareListViewItems(Student[] student) 
{ 
ArrayList<HashMap<String,Object>> listdata = new ArrayList<HashMap<String,Object>>(); 

for(int index=0;index<student.size();index++) 
{ 
    HashMap<String,Object> data = new HashMap<String,Object>(); 
    data.put("roll", student[indxe].roll); 
    data.put("address", student[indxe].address); 
    data=null; 
    listdata.add(data); 

} 

return data; 
} 

private void setListAdapter(Student[] students) 
{ 
    TestListAdapter adapter = new TestListAdapter(prepareListViewItems(students)) 
    list.setAdapter(adapter); 
} 

但是，當你創建一個自定義適配器，也沒有必要創建的HashMap，只有陣列將滿足你的目的。

Answer 3

HashMap由2個集合（或更好的1個集合和1個集合）組成，所以通過擴展ArrayAdapter是不可能的;但你可以很容易地得到一個集合（或更好的集）的Map.Entry的，並將其轉換爲一個列表：

來源：

Map<String, Object> map = new HashMap<String, Object>(); 

到：

List<Map.Entry<String, Object>> list = new ArrayList(map.entrySet()); 

於是我就用派生ArrayAdapter像這樣的：

class HashMapArrayAdapter extends ArrayAdapter { 

     private static class ViewHolder { 
      TextView tV1; 
      TextView tV2; 
     } 

     public HashMapArrayAdapter(Context context, int textViewResourceId, List<Map.Entry<String, Object>> objects) { 
      super(context, textViewResourceId, objects); 
     } 

     @Override 
     public View getView(int position, View convertView, ViewGroup parent) { 

      ViewHolder viewHolder; 

      if (convertView == null) { 
       convertView = LayoutInflater.from(getContext()).inflate(android.R.layout.simple_list_item_2, parent, false); 
       viewHolder = new ViewHolder(); 
       viewHolder.tV1 = (TextView) convertView.findViewById(android.R.id.text1); 
       viewHolder.tV2 = (TextView) convertView.findViewById(android.R.id.text2); 
       convertView.setTag(viewHolder); 
      } else 
       viewHolder = (ViewHolder) convertView.getTag(); 

      Map.Entry<String, Object> entry = (Map.Entry<String, Object>) this.getItem(position); 

      viewHolder.tV1.setText(entry.getKey()); 
      viewHolder.tV2.setText(entry.getValue().toString()); 
      return convertView; 
     } 

然後創建適配器：

ArrayAdapter adapter = new HashMapArrayAdapter(this.getActivity(), android.R.layout.simple_list_item_2, new ArrayList(map.entrySet()));