我有ListView。 ListView的行中有ImageView。我已将onClick属性附加到ImageView，而我的onClick函数是
public void alarmClick(View v)
{
ImageView bell = (ImageView)v.findViewById(R.id.mEventImage);
bell.setImageResource(R.drawable.bell_on);
if(bell.getTag() == null)
{
bell.setImageResource(R.drawable.bell_on);
bell.setTag(R.drawable.bell_on);
}
else if((Integer)bell.getTag() == R.drawable.bell_on)
{
bell.setImageResource(R.drawable.bell_off);
bell.setTag(R.drawable.bell_off);
}
else
{
bell.setImageResource(R.drawable.bell_on);
bell.setTag(R.drawable.bell_on);
}
}
我正在尝试切换ImageView来源，但是当我点击ImageView当时不在屏幕上的许多其他行ImageView也会切换。这可能是因为视图在ListView中被回收。有关如何为每个唯一行做的任何建议。
适配器类
package com.example.drawer;
import java.util.ArrayList;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;
public class EventAdapter extends ArrayAdapter<EventList> {
Context context;
ArrayList<EventList> data;
int layoutResourceId;
public EventAdapter(Context context, int textViewResourceId, ArrayList<EventList> data) {
super(context, textViewResourceId, data);
this.context = context;
this.data = data;
this.layoutResourceId = textViewResourceId;
// TODO Auto-generated constructor stub
}
@Override
public View getView(int position, View convertView, ViewGroup parent)
{
View row = convertView;
EventHolder holder = null;
if(row == null)
{
LayoutInflater inflator = ((Activity)context).getLayoutInflater();
row = inflator.inflate(layoutResourceId, parent, false);
holder = new EventHolder();
holder.coord = (TextView)row.findViewById(R.id.eventCoor);
holder.icon = (ImageView)row.findViewById(R.id.icon);
holder.eventName = (TextView)row.findViewById(R.id.eventNam);
holder.location = (TextView)row.findViewById(R.id.eventLoc);
holder.time = (TextView)row.findViewById(R.id.eventTime);
row.setTag(holder);
}
else
{
holder = (EventHolder)row.getTag();
}
EventList listItem = data.get(position);
ImageHelper imageHelper = new ImageHelper();
Bitmap icon = BitmapFactory.decodeResource(context.getResources(), R.drawable.ipl);
Bitmap newIcon = imageHelper.getRoundedCornerBitmap(icon, 200);
holder.coord.setText(listItem.coord);
holder.eventName.setText(listItem.eventName);
holder.location.setText(listItem.location);
holder.time.setText(listItem.time);
holder.icon.setImageBitmap(newIcon);
holder.id = listItem.id;
holder.day = listItem.day;
//Log.d("ListView", "Executed");
return row;
}
static class EventHolder
{
ImageView icon;
TextView eventName;
TextView location;
TextView time;
TextView coord;
int id;
int day;
}
}
答案 0 :(得分：0)
是的，原因是视图被回收并且同一个ImageView将用于另一行。
你的列表项 - EventList，现在应该打开或关闭它的铃声，并在getView中适当地设置它。这意味着如果用户录制了第一个项目并设置了铃声，当其他项目重新使用该视图时，它会将其更改为关闭。
答案 1 :(得分：0)
我建议你使用Cursor Loaders并让你的Activity / Fragment实现LoaderCallbacks，使用游标是相当简单的。使用Sqlite数据库或任何其他数据库管理您的EventData，并使用ContentProvider检索您的数据
另外，让EventAdapter扩展CursorAdapter，然后覆盖以下方法： -
public class EventAdapter extends CursorAdapter {
int layoutResourceId;
public EventAdapter(Context context, int textViewResourceId)
{
super(context, textViewResourceId, data);
this.layoutResourceId = textViewResourceId;
}
static class EventHolder
{
final ImageView icon;
final ImageView bell;
final TextView eventName;
final TextView location;
final TextView time;
final TextView coord;
final int id;
final int day;
EventHolder(View view)
{
coord = (TextView)view.findViewById(R.id.eventCoor);
icon = (ImageView)view.findViewById(R.id.icon);
bell = (ImageView) view.findViewById(R.id.mEventImage);
eventName = (TextView)view.findViewById(R.id.eventNam);
location = (TextView)view.findViewById(R.id.eventLoc);
time = (TextView)view.findViewById(R.id.eventTime);
id = -1;
day = -1;
}
}
//Re use the visible views
@Override
public void bindView(View view, Context context, Cursor cursor)
{
ViewHolder holder = (ViewHolder) view.getTag();
EventList listItem = cursor.get(position);
ImageHelper imageHelper = new ImageHelper();
Bitmap icon = BitmapFactory.decodeResource(context.getResources(), R.drawable.ipl);
Bitmap newIcon = imageHelper.getRoundedCornerBitmap(icon, 200);
holder.coord.setText(listItem.coord);
holder.eventName.setText(listItem.eventName);
holder.location.setText(listItem.location);
holder.time.setText(listItem.time);
holder.icon.setImageBitmap(newIcon);
holder.id = listItem.id;
holder.day = listItem.day;
//Checking Bell State Columnview if it is OFF or ON
if(cursor.getString(YourActivity.COL_EVENTBELL_IMAGEVIEW_STATE).equals("on"))
{
holder.bell.setImageResource(R.drawable.bell_on);
}
else
{
holder.bell.setImageResource(R.drawable.bell_off);
}
}
//Create new views, all to be visible at once
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent)
{
View view = LayoutInflater.from(context).inflate(layoutResourceId, parent, false);
EventHolder holder = new EventHolder(view);
view.setTag(holder);
return view;
}
}
在你的Activity / Fragments中你可以使用听众来更新铃声的状态，你的AlarmClick（）会是这样的
public void alarmClick()
{
Cursor cursor = mEventAdapter.getCursor();
ContentValues eventValues = new ContentValues();
String event_bell_state = cursor.getString(YourActivity.COL_EVENT_BELL_IMAGEVIEW_STATE);
String event_bell_id = cursor.getString(YourActivity.COL_EVENTBELL_ID);
if(event_bell_state == "on")
{
eventValues.put(YourActivity.COL_EVENTBELL_IMAGEVIEW_STATE, "off");
}
else
{
eventValues.put(YourActivity.COL_EVENTBELL_IMAGEVIEW_STATE, "on");
}
String whereClause = YourActivity.COL_EVENTBELL_ID + " = ?";
String[] selectionArgs = new String[]{String.valueOf(event_bell_id)};
getActivity().getApplicationContext().getContentResolver().update(EventEntry.CONTENT_URI, eventValues, whereClause, selectionArgs);
mEventAdapter.notifyDataSetChanged();
getLoaderManager().restartLoader(EVENTLIST_LOADER, null, this);
}