我正在使用SimpleCursorAdapter和ListView来展示通过Loader加载的一些数据。在cursor中,我有一些带有int类型的项,范围从0到3。
我想要这个int等于0-1的项具有一个布局(右对齐、一种颜色),而2-3的项具有另一个布局(左对齐、另一种颜色)。就像一个聊天应用程序,发送的消息在右侧,接收的消息在左侧。
有没有一种简单的方法来做到这一点?例如使用switch,在范围为0-1时填充layout_1,在范围为2-3时填充layout_2。
编辑:我已经添加了我正在尝试填充的ListFragment的代码。要用作开关的int是MyContentProvider.Data.E_TYPE。我不太懂,但也许有人能清楚地解释我需要写什么!
我想要这个int等于0-1的项具有一个布局(右对齐、一种颜色),而2-3的项具有另一个布局(左对齐、另一种颜色)。就像一个聊天应用程序,发送的消息在右侧,接收的消息在左侧。
有没有一种简单的方法来做到这一点?例如使用switch,在范围为0-1时填充layout_1,在范围为2-3时填充layout_2。
编辑:我已经添加了我正在尝试填充的ListFragment的代码。要用作开关的int是MyContentProvider.Data.E_TYPE。我不太懂,但也许有人能清楚地解释我需要写什么!
import com.actionbarsherlock.view.Menu;
import com.actionbarsherlock.view.MenuInflater;
import com.corsalini.survcontr.MyContentProvider.Data;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.database.Cursor;
import android.os.Bundle;
import android.support.v4.app.ListFragment;
import android.support.v4.content.CursorLoader;
import android.support.v4.app.LoaderManager;
import android.support.v4.content.Loader;
import android.support.v4.widget.CursorAdapter;
import android.support.v4.widget.SimpleCursorAdapter;
import android.util.Log;
import android.view.View;
import android.widget.ListView;
public class FragEvents extends ListFragment implements LoaderManager.LoaderCallbacks<Cursor>{
@Override
public void onPause() {
allRead();
super.onPause();
}
private static final int EVENTS_LOADER = 0x02;
// This is the Adapter being used to display the list's data.
SimpleCursorAdapter mAdapter;
// If non-null, this is the current filter the user has provided.
String mCurFilter;
@Override public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
// Give some text to display if there is no data. In a real
// application this would come from a resource.
setEmptyText(this.getString(R.string.perform_event));
// We have a menu item to show in action bar.
setHasOptionsMenu(true);
// Create an empty adapter we will use to display the loaded data.
mAdapter = new SimpleCursorAdapter(getActivity(),
android.R.layout.simple_list_item_2, null,
new String[] { MyContentProvider.Data.E_TEXT, MyContentProvider.Data.E_DATE,
MyContentProvider.Data.E_NUMBER, MyContentProvider.Data.E_TYPE },
new int[] { android.R.id.text1, android.R.id.text2 },
CursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);
setListAdapter(mAdapter);
// Start out with a progress indicator.
setListShown(false);
// Prepare the loader. Either re-connect with an existing one,
// or start a new one.
getActivity().getSupportLoaderManager().initLoader(EVENTS_LOADER, null, this);
}
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.menu_events, menu);
}
@Override public void onListItemClick(ListView l, View v, int position, long id) {
//TODO Insert desired behavior here.
Log.i("FragmentComplexList", "Item clicked: " + id);
}
// These are the Contacts rows that we will retrieve.
static final String[] SUMMARY_PROJECTION = new String[] {
MyContentProvider.Data.E_ID,
MyContentProvider.Data.E_DATE,
MyContentProvider.Data.E_NUMBER,
MyContentProvider.Data.E_TEXT,
MyContentProvider.Data.E_TYPE,
};
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
return new CursorLoader(getActivity(), MyContentProvider.Data.CONTENT_URI_EVENTS,
SUMMARY_PROJECTION, null, null,
Data.E_ID + " DESC");
}
public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
// Swap the new cursor in. (The framework will take care of closing the
// old cursor once we return.)
mAdapter.swapCursor(data);
// The list should now be shown.
if (isResumed()) {
setListShown(true);
} else {
setListShownNoAnimation(true);
}
}
public void onLoaderReset(Loader<Cursor> loader) {
// This is called when the last Cursor provided to onLoadFinished()
// above is about to be closed. We need to make sure we are no
// longer using it.
mAdapter.swapCursor(null);
}
public void deleteEvent(ContentResolver contentResolver,
long id){
String selection = Data.E_ID + "=";
String[] args = {String.valueOf(id)};
contentResolver.delete(Data.CONTENT_URI_EVENTS, selection, args);
}
public void allRead(){
ContentResolver contentResolver = getActivity().getContentResolver();
ContentValues contentValue = new ContentValues();
contentValue.put(Data.E_NUMBER, Data.RECEIVED_READ);
String selection= Data.E_TYPE+"=";
String[] args= {String.valueOf(Data.RECEIVED_UNREAD)};
contentResolver.update(Data.CONTENT_URI_EVENTS, contentValue, selection, args);
}
}
编辑:如果我理解正确,我的最终EventsAdapter(继承自SimpleCursorAdapter)应该如下所示:
import android.content.Context;
import android.database.Cursor;
import android.support.v4.widget.SimpleCursorAdapter;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class EventsAdapter extends SimpleCursorAdapter {
private Context localContext;
public EventsAdapter(Context context, int layout, Cursor c, String[] from,
int[] to, int flags) {
super(context, layout, c, from, to, flags);
localContext = context;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
Cursor c= getCursor();
c.moveToPosition(position);
if(convertView == null)
{
LayoutInflater layoutInflator = (LayoutInflater)localContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
switch (getItemViewType(position)){
case 0:
convertView = layoutInflator.inflate(R.layout.item_event_0, null);
break;
case 1:
convertView = layoutInflator.inflate(R.layout.item_event_1, null);
break;
case 2:
convertView = layoutInflator.inflate(R.layout.item_event_2, null);
break;
case 3:
convertView = layoutInflator.inflate(R.layout.item_event_3, null);
break;
}
}
switch (getItemViewType(position)){
case 0:
TextView date0=(TextView)convertView.findViewById(R.id.date0);
TextView text0=(TextView)convertView.findViewById(R.id.text0);
date0.setText(""+c.getString(c.getColumnIndex(Data.E_DATE)));
text0.setText(""+c.getString(c.getColumnIndex(Data.E_TEXT)));
break;
case 1:
TextView date1=(TextView)convertView.findViewById(R.id.date1);
TextView text1=(TextView)convertView.findViewById(R.id.text1);
date1.setText(""+c.getString(c.getColumnIndex(Data.E_DATE)));
text1.setText(""+c.getString(c.getColumnIndex(Data.E_TEXT)));
case 2:
TextView date2=(TextView)convertView.findViewById(R.id.date2);
TextView text2=(TextView)convertView.findViewById(R.id.text2);
date2.setText(""+c.getString(c.getColumnIndex(Data.E_DATE)));
text2.setText(""+c.getString(c.getColumnIndex(Data.E_TEXT)));
case 3:
TextView date3=(TextView)convertView.findViewById(R.id.date3);
TextView text3=(TextView)convertView.findViewById(R.id.text3);
date3.setText(""+c.getString(c.getColumnIndex(Data.E_DATE)));
text3.setText(""+c.getString(c.getColumnIndex(Data.E_TEXT)));
}
return convertView;
}
@Override
public int getItemViewType(int position) {
int type = 0;
int returnInt = 0;
Cursor c= getCursor();
c.moveToPosition(position);
type= c.getInt(c.getColumnIndex(Data.E_TYPE));
switch (type){
case Data.RECEIVED_READ:
returnInt=3;
case Data.RECEIVED_UNREAD:
returnInt= 2;
case Data.SENT_COMPLETED:
returnInt= 1;
case Data.SENT_PROGRESS:
returnInt= 0;
default:
returnInt=0;
}
return returnInt;
}
@Override
public int getViewTypeCount() {
return 4;
}
}