我想创建 infinie GridView，当我滚动时，如果在 onScroll 方法中不添加
adapter = new ImageAdapter();
grid.setAdapter(adapter);
我的应用程序与LogCat崩溃 ：
FATAL EXCEPTION: main
java.lang.IndexOutOfBoundsException: Invalid index 46, size is 46
at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:251)
at java.util.ArrayList.get(ArrayList.java:304)
at com.example.tectob6iu.MainActivity$ImageAdapter.getView(MainActivity.java:98)
at android.widget.AbsListView.obtainView(AbsListView.java:2143)
at android.widget.GridView.makeAndAddView(GridView.java:1341)
at android.widget.GridView.makeRow(GridView.java:341)
at android.widget.GridView.fillDown(GridView.java:283)
at android.widget.GridView.fillGap(GridView.java:243)
at android.widget.AbsListView.trackMotionScroll(AbsListView.java:4930)
at android.widget.AbsListView$FlingRunnable.run(AbsListView.java:4087)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
at android.view.Choreographer.doCallbacks(Choreographer.java:562)
at android.view.Choreographer.doFrame(Choreographer.java:531)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
at android.os.Handler.handleCallback(Handler.java:725)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5191)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562)
at dalvik.system.NativeStart.main(Native Method)
MainActivity.class
public class MainActivity extends Activity implements OnScrollListener{
private class ImageAdapter extends BaseAdapter {
private List<String> list;
private ImageLoader loader;
private DisplayImageOptions options;
public ImageAdapter() {
this(new ArrayList<String>());
options = new DisplayImageOptions.Builder()
.cacheInMemory()
.cacheOnDisc()
.bitmapConfig(Bitmap.Config.RGB_565)
.displayer(new FadeInBitmapDisplayer(250))
.build();
loader = ImageLoader.getInstance();
loader.init(ImageLoaderConfiguration.createDefault(MainActivity.this));
}
public void clear() {
list.clear();
notifyDataSetChanged();
}
public void add(List<String> rows) {
list.addAll(rows);
notifyDataSetChanged();
}
@Override
public int getCount() {
return list.size();
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public String getItem(int position) {
return list.get(position);
}
public View getView(int position, View view, ViewGroup container) {
if (view == null) {
view = getLayoutInflater().inflate(R.layout.grid_item, container, false);
}
ImageView image = (ImageView)view.findViewById(R.id.imageGrid);
// Bind row on your view here 97
//98
if(str.size() > 0){
loader.displayImage(str.get(position), image, options);
}
else{
image.setImageResource(R.drawable.ic_launcher);
}
return view;
}
public ImageAdapter(List<String> list) {
this.list = list;
}
}
class LoadTask extends AsyncTask<Void, Void, List<String>> {
private int page = 1;
public int addPage(int i){
return page = i;
}
@Override
protected List<String> doInBackground(Void... params) {
InputStream ips = null;
JSONObject jsonObj = null;
String json = "";
try {
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpResponse response = httpClient.execute(new HttpPost("http://iapp.gazeta.uz/fotolenta?page="+page));
ips = response.getEntity().getContent();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader bufff = new BufferedReader(new InputStreamReader(ips, "UTF-8"));
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = bufff.readLine()) != null){
sb.append(line + "\n");
}
ips.close();
json = sb.toString();
} catch (Exception e) {
e.printStackTrace();
}
try {
jsonObj = new JSONObject(json);
} catch (JSONException e) {
e.printStackTrace();
}
JSONArray array = null;
array = jsonObj.optJSONArray("img_list");
for (int i = 0; i < array.length(); i++) {
str.add(array.optJSONObject(i).optString("thumbnail"));
}
return str;
}
@Override
protected void onPostExecute(List<String> result) {
adapter.add(result);
}
}
ArrayList<String> str = new ArrayList<String>();
private GridView grid;
private ImageAdapter adapter;
private int page;
private int mVisibleThreshold = 5;
private int mCurrentPage = 0;
private int mPreviousTotal = 0;
private boolean mLoading = true;
private boolean mLastPage = false;
public void refresh(int i){
LoadTask task = new LoadTask();
task.addPage(i);
task.execute();
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
page = 1;
refresh(page);
setContentView(R.layout.main);
grid = (GridView) findViewById(R.id.grid);
adapter = new ImageAdapter();
grid.setAdapter(adapter);
grid.setOnScrollListener(this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu){
getMenuInflater().inflate(R.menu.activity_main, menu);
return super.onCreateOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item){
page ++;
refresh(page);
adapter = new ImageAdapter();
grid.setAdapter(adapter);
return super.onOptionsItemSelected(item);
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
// TODO Auto-generated method stub
if (mLoading) {
if (totalItemCount > mPreviousTotal) {
mLoading = false;
mPreviousTotal = totalItemCount;
mCurrentPage++;
// Find your own condition in order to know when you
// have finished displaying all items
if (mCurrentPage + 1 > 50) {
mLastPage = true;
}
}
}
if (!mLastPage && !mLoading &&
(totalItemCount - visibleItemCount) <= (firstVisibleItem + mVisibleThreshold)) {
page++;
refresh(page);
adapter = new ImageAdapter();
grid.setAdapter(adapter);
mLoading = true;
}
}
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
// TODO Auto-generated method stub
}
}
否则我的应用程序可以工作，但是当我滚动到结束网格视图刷新并丢失位置并且我需要再次滚动到我的最后一个位置时，如何解决这个问题？