您的活动类不扩展ListActivity。因此错误 3 和 4
您应该AsyncTask用于网络相关操作。您不能在主 ui 线程上运行网络相关操作。
您应该对图像使用延迟加载。但是对于示例，我使用了位图的 ArrayList 作为缩略图。您可能会遇到内存泄漏。所以使用延迟加载。根据您的要求修改以下内容。
例子：
public class MainActivity extends Activity {
Button b;
ListView lv;
ArrayList<String> msg = new ArrayList<String>();
ArrayList<String> title = new ArrayList<String>();
ArrayList<Bitmap> thumb = new ArrayList<Bitmap>();
ProgressDialog pd;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
lv= (ListView) findViewById(R.id.lv);
pd = new ProgressDialog(MainActivity.this);
pd.setTitle("Loading..");
b= (Button) findViewById(R.id.button1);
b.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
new TheTask().execute();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public void getData()
{
HttpClient httpclient = new DefaultHttpClient();
httpclient.getParams().setParameter(CoreProtocolPNames.PROTOCOL_VERSION, HttpVersion.HTTP_1_1);
HttpGet request = new HttpGet("https://gdata.youtube.com/feeds/api/videos?q=random&max-results=50&v=2&alt=jsonc");
// HttpGet request = new HttpGet("http://gdata.youtube.com/feeds/api/users/mbbangalore/uploads?v=2&alt=jsonc");
try
{
HttpResponse response = httpclient.execute(request);
HttpEntity resEntity = response.getEntity();
String _response=EntityUtils.toString(resEntity); // content will be consume only once
JSONObject json = new JSONObject(_response);
JSONArray jsonArray = json.getJSONObject("data").getJSONArray("items");
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObject = jsonArray.getJSONObject(i);
String title1 = jsonObject.getString("title");
title.add(title1);
String thumbUrl = jsonObject.getJSONObject("thumbnail").getString("sqDefault");
URL url1 = new URL(thumbUrl);
Bitmap bmp = BitmapFactory.decodeStream(url1.openConnection().getInputStream());
thumb.add(bmp);
String url;
try {
url = jsonObject.getJSONObject("player").getString("default");
msg.add(url);
} catch (JSONException ignore) {
}
}
}
catch(Exception e1)
{
e1.printStackTrace();
}
httpclient.getConnectionManager().shutdown();
}
class TheTask extends AsyncTask<Void,Void,Void>
{
@Override
protected void onPostExecute(Void result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
pd.dismiss();
YouTubeAdapter you = new YouTubeAdapter(MainActivity.this,msg,title,thumb);
lv.setAdapter(you);
}
@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
pd.show();
}
@Override
protected Void doInBackground(Void... params) {
// TODO Auto-generated method stub
getData();
return null;
}
}
}
activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<ListView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/lv"
android:layout_above="@+id/button1"
/>
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:text="Button" />
</RelativeLayout>
YouTube 适配器
public class YouTubeAdapter extends BaseAdapter{
Context mContext;
Intent intent;
LayoutInflater mInflater;
ArrayList<String> mVideo= new ArrayList<String>();
ArrayList<String> mTitle= new ArrayList<String>();
ArrayList<Bitmap> mThumb= new ArrayList<Bitmap>();
public YouTubeAdapter(Context context,ArrayList<String> a,ArrayList title,ArrayList thumb) {
mContext=context;
mVideo=a;
mTitle = title;
mThumb= thumb;
mInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return mVideo.size();
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public View getView(final int position, View arg1, ViewGroup arg2) {
ViewHolder vh;
if(arg1==null)
{
arg1=mInflater.inflate(R.layout.video, null);
vh= new ViewHolder();
vh.tv=(TextView)arg1.findViewById(R.id.tvv);
vh.iv=(ImageView)arg1.findViewById(R.id.ivv);
arg1.setTag(vh);
}
else
{
vh= (ViewHolder)arg1.getTag();
}
vh.tv.setText(mTitle.get(position));
vh.iv.setImageBitmap(mThumb.get(position));
return arg1;
}
static class ViewHolder
{
TextView tv;
ImageView iv;
}
}
视频.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
>
<TextView
android:id="@+id/tvv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:textColor="#000000"
android:textSize="13dp" />
<ImageView
android:id="@+id/ivv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
</LinearLayout>
快照
