我正在从服务器加载图像以及文本并在gridview中显示它们，我正在使用基础适配器来填充网格。以下是适配器的代码：
package com.erc.test;
import java.util.ArrayList;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;
public class CustomGrid2 extends BaseAdapter{
private Context mContext;
private final ArrayList<String> web;
private final ArrayList<String> Imageid;
public CustomGrid2(Context c,ArrayList<String> web, ArrayList<String> imageId ) {
mContext = c;
this.Imageid = imageId;
this.web = web;
}
public void removeItem(int position){
web.remove(position);
Imageid.remove(position);
notifyDataSetChanged();
}
public void clearitems(){
web.clear();
Imageid.clear();
notifyDataSetChanged();
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return web.size();
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return null;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
///////////////////////////////////
View grid;
if (convertView == null) { // if it's not recycled, initialize some attributes
LayoutInflater inflater = (LayoutInflater) mContext.getSystemService( Context.LAYOUT_INFLATER_SERVICE );
grid = inflater.inflate(R.layout.grid_single, parent, false);
} else {
grid = (View) convertView;
}
TextView text = (TextView)grid.findViewById(R.id.textView1);
text.setText(web.get(position));
RoundedImageView image = (RoundedImageView)grid.findViewById(R.id.grid_image);
image.setPlaceholderImage(R.drawable.ic_launcher);
image.setImageUrl(Imageid.get(position));
// image.setImageDrawable();
return grid;
////////////////////////////////////////////////////
}
}
在我的主要课程中，我正在做以下事情：
package com.erc.test;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.util.ArrayList;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.content.Intent;
import android.graphics.drawable.Drawable;
import android.net.ParseException;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.StrictMode;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.GridView;
import android.widget.ProgressBar;
import android.widget.Toast;
public class Categories extends Activity {
HttpResponse response;
HttpEntity entity;
HttpClient httpclient;
HttpPost httppost;
GridView grid;
ProgressBar pb;
CustomGrid2 adapter;
Drawable[] dd=null;
ArrayList<String> actorsList;
ArrayList<String> title;
JSONArray jarray;
ArrayList<String> namearray= new ArrayList<String>();
ArrayList<Drawable> imagearray= new ArrayList<Drawable>();
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.categories);
grid=(GridView)findViewById(R.id.gridView1);
pb=(ProgressBar)findViewById(R.id.progressBar1);
actorsList = new ArrayList<String>();
title = new ArrayList<String>();
new ProgressTask().execute();
}
class ProgressTask extends AsyncTask <Void,Void,Void>
{
@Override
protected void onPreExecute()
{
pb.setVisibility(View.VISIBLE);
}
@Override
protected Void doInBackground(Void... arg0) {
// TODO Auto-generated method stub
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
try {
//------------------>>
HttpGet httppost = new HttpGet("http://www.page.com/folder/file.php?userid=2&client=android&sandbox=0&language=en&format=json");
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response = httpclient.execute(httppost);
// StatusLine stat = response.getStatusLine();
int status = response.getStatusLine().getStatusCode();
if (status == 200) {
HttpEntity entity = response.getEntity();
String data = EntityUtils.toString(entity);
JSONObject jsono = new JSONObject(data);
jarray = jsono.getJSONArray("categories");
}
//------------------>>
} catch (ParseException e1) {
// Toast.makeText(getBaseContext(), e1.toString(),Toast.LENGTH_LONG).show();
// e1.printStackTrace();
} catch (IOException e) {
// e.printStackTrace();
//Toast.makeText(getBaseContext(), e.toString(),Toast.LENGTH_LONG).show();
} catch (JSONException e) {
// e.printStackTrace();
//Toast.makeText(getBaseContext(), e.toString(),Toast.LENGTH_LONG).show();
}
return null;
}
@Override
protected void onPostExecute(Void result)
{
try
{
for (int i = 0; i < jarray.length(); i++) {
JSONObject object = jarray.getJSONObject(i);
// Actors actor = new Actors();
actorsList.add(object.getString("picture").replace("https","http"));
title.add(object.getString("name"));}
}
catch(Exception ex)
{
Toast.makeText(getBaseContext(), ex.toString(),Toast.LENGTH_LONG).show();
}
// Log.d("title is",object.getString("image"));
// adapter = new CustomGrid2(MainActivity.this, title, actorsList);
// grid.setAdapter(adapter);
// actor.setImage(object.getString("image"));
// actorsList.add(actor);
pb.setVisibility(View.GONE);
adapter = new CustomGrid2(Categories.this, title, actorsList);
grid.setAdapter(adapter);
adapter.notifyDataSetChanged();
// grid.setOnItemClickListener(new OnItemClickListener() {
//
// @Override
// public void onItemClick(AdapterView<?> arg0, View arg1,
// int arg2, long arg3) {
// // TODO Auto-generated method stub
// String id=String.valueOf(arg2+1);
// String category_name=namearray.get(arg2);
// Intent intent = new Intent(Categories.this, Subcategories.class);
// Bundle b = new Bundle();
// b.putString("ID",id); //Your id
// b.putString("Name",category_name);
// intent.putExtras(b); //Put your id to your next Intent
// startActivity(intent);
//
// }
// });
}
}
// private static String convertStreamToString(InputStream is)
// {
//
//
// BufferedReader reader = new BufferedReader(new InputStreamReader(is));
// StringBuilder sb = new StringBuilder();
// String line = null;
// try
// {
//
// while ((line = reader.readLine()) != null) {
// sb.append(line + "\n");
// }
// }catch(IOException e)
// {
//
// }
// finally
// {
// try{
// is.close();
// }catch(IOException e)
// {
//
// }
// }return sb.toString();
//
//
//
// }
}
在下面的课程中，我给imageview一个圆形的形状，然后从url下载图像：
package com.erc.test;
import java.io.BufferedInputStream;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import org.apache.http.util.ByteArrayBuffer;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.AsyncTask;
import android.util.AttributeSet;
import android.widget.ImageView;
public class RoundedImageView extends ImageView {
private Drawable placeholder, image;
public RoundedImageView(Context context) {
super(context);
// TODO Auto-generated constructor stub
}
public RoundedImageView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public RoundedImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
protected void onDraw(Canvas canvas) {
Drawable drawable = getDrawable();
if (drawable == null) {
return;
}
if (getWidth() == 0 || getHeight() == 0) {
return;
}
Bitmap b = ((BitmapDrawable)drawable).getBitmap() ;
Bitmap bitmap = b.copy(Bitmap.Config.ARGB_8888, true);
int w = getWidth(), h = getHeight();
Bitmap roundBitmap = getCroppedBitmap(bitmap, w);
canvas.drawBitmap(roundBitmap, 0,0, null);
}
public void setPlaceholderImage(Drawable drawable) {
placeholder = drawable;
if (image == null) {
setImageDrawable(placeholder);
}
}
public void setPlaceholderImage(int resid) {
placeholder = getResources().getDrawable(resid);
if (image == null) {
setImageDrawable(placeholder);
}
}
public void setImageUrl(String url) {
DownloadTask task = new DownloadTask();
task.execute(url);
}
private class DownloadTask extends AsyncTask<String, Void, Bitmap> {
@Override
protected Bitmap doInBackground(String... params) {
String url = params[0];
try {
URLConnection conn = (new URL(url)).openConnection();
InputStream is = conn.getInputStream();
BufferedInputStream bis = new BufferedInputStream(is);
ByteArrayBuffer baf = new ByteArrayBuffer(50);
int current = 0;
while ((current=bis.read()) != -1) {
baf.append((byte)current);
}
byte[] imageData = baf.toByteArray();
return BitmapFactory.decodeByteArray(imageData, 0, imageData.length);
} catch (Exception e) {
return null;
}
}
@Override
protected void onPostExecute(Bitmap result) {
image = new BitmapDrawable(result);
if (image != null) {
setImageDrawable(image);
}
}
}
public Bitmap getCroppedBitmap(Bitmap bmp, int radius) {
Bitmap sbmp;
if(bmp.getWidth() != radius || bmp.getHeight() != radius)
sbmp = Bitmap.createScaledBitmap(bmp, radius, radius, false);
else
sbmp = bmp;
Bitmap output = Bitmap.createBitmap(sbmp.getWidth(),
sbmp.getHeight(), Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final int color = 0xffa19774;
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, sbmp.getWidth(), sbmp.getHeight());
paint.setAntiAlias(true);
paint.setFilterBitmap(true);
paint.setDither(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(Color.parseColor("#BAB399"));
canvas.drawCircle(sbmp.getWidth() / 2+0.7f, sbmp.getHeight() / 2+0.7f,
sbmp.getWidth() / 2+0.1f, paint);
paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
canvas.drawBitmap(sbmp, rect, rect, paint);
return output;
}
}
问题是当我滚动网格时图像改变位置，请问有什么帮助吗？