Android：如何在ListView中显示来自Web的图像？我有以下代码来显示ImageView中URL的图像：
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import android.app.ListActivity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.widget.ImageView;
public class HttpImgDownload extends ListActivity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Bitmap bitmap =
// DownloadImage(
// "http://www.streetcar.org/mim/cable/images/cable-01.jpg");
DownloadImage(
"http://s.twimg.com/a/1258674567/images/default_profile_3_normal.png");
ImageView img = (ImageView) findViewById(R.id.img);
img.setImageBitmap(bitmap);
}
private InputStream OpenHttpConnection(String urlString)
throws IOException
{
InputStream in = null;
int response = -1;
URL url = new URL(urlString);
URLConnection conn = url.openConnection();
if (!(conn instanceof HttpURLConnection))
throw new IOException("Not an HTTP connection");
try{
HttpURLConnection httpConn = (HttpURLConnection) conn;
httpConn.setAllowUserInteraction(false);
httpConn.setInstanceFollowRedirects(true);
httpConn.setRequestMethod("GET");
httpConn.connect();
response = httpConn.getResponseCode();
if (response == HttpURLConnection.HTTP_OK) {
in = httpConn.getInputStream();
}
}
catch (Exception ex)
{
throw new IOException("Error connecting");
}
return in;
}
private Bitmap DownloadImage(String URL)
{
Bitmap bitmap = null;
InputStream in = null;
try {
in = OpenHttpConnection(URL);
bitmap = BitmapFactory.decodeStream(in);
in.close();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
return bitmap;
}
}
现在我如何在列表视图中以数组形式显示图像？以下是我想要显示图像的方式：http://sites.google.com/site/androideyecontact/_/rsrc/1238086823282/Home/android-eye-contact-lite/eye_contact-list_view_3.png?height=420&width=279
这就是我想出的：
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import android.app.Activity;
import android.os.Bundle;
import android.app.ListActivity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.view.View;
import android.view.ViewGroup;
import android.view.LayoutInflater;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
public class ImageFromWeb extends ListActivity {
/** Called when the activity is first created. */
TextView selection;
Bitmap bitmap;
String[] items={"lorem", "ipsum", "dolor", "sit", "amet",
"consectetuer", "adipiscing", "elit", "morbi", "vel",
"ligula", "vitae", "arcu", "aliquet", "mollis",
"etiam", "vel", "erat", "placerat", "ante",
"porttitor", "sodales", "pellentesque", "augue",
"purus"};
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.main);
bitmap =
DownloadImage(
"http://www.streetcar.org/mim/cable/images/cable-01.jpg");
//DownloadImage(
// "http://s.twimg.com/a/1258674567/images/default_profile_3_normal.png");
//ImageView img = (ImageView) findViewById(R.id.img);
//icon.setImageBitmap(bitmap);
//icon
// ImageView icon=(ImageView)row.findViewById(R.id.icon);
//setListAdapter(new IconicAdapter());
//selection=(TextView)findViewById(R.id.selection);
}
private InputStream OpenHttpConnection(String urlString)
throws IOException
{
InputStream in = null;
int response = -1;
URL url = new URL(urlString);
URLConnection conn = url.openConnection();
if (!(conn instanceof HttpURLConnection))
throw new IOException("Not an HTTP connection");
try{
HttpURLConnection httpConn = (HttpURLConnection) conn;
httpConn.setAllowUserInteraction(false);
httpConn.setInstanceFollowRedirects(true);
httpConn.setRequestMethod("GET");
httpConn.connect();
response = httpConn.getResponseCode();
if (response == HttpURLConnection.HTTP_OK) {
in = httpConn.getInputStream();
}
}
catch (Exception ex)
{
throw new IOException("Error connecting");
}
return in;
}
private Bitmap DownloadImage(String URL)
{
Bitmap bitmap = null;
InputStream in = null;
try {
in = OpenHttpConnection(URL);
bitmap = BitmapFactory.decodeStream(in);
in.close();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
return bitmap;
}
public void onListItemClick(ListView parent, View v,
int position, long id) {
selection.setText(items[position]);
}
class IconicAdapter extends ArrayAdapter {
IconicAdapter() {
super(ImageFromWeb.this, R.layout.row, items);
}
public View getView(int position, View convertView,
ViewGroup parent) {
LayoutInflater inflater=getLayoutInflater();
View row=inflater.inflate(R.layout.row, parent, false);
TextView label=(TextView)row.findViewById(R.id.label);
label.setText(items[position]);
ImageView icon=(ImageView)row.findViewById(R.id.icon);
//if (items[position].length()>4) {
//icon.setImageResource(R.drawable.delete);
//icon.setI
icon.setImageBitmap(bitmap);
//}
//else {
//icon.setImageResource(R.drawable.ok);
//}
return(row);
}
}
}
main.xml中
<TextView
android:id="@+id/selection"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>
<ListView
android:id="@android:id/list"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:drawSelectorOnTop="false"
>
row.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
>
<ImageView
android:id="@+id/icon"
android:layout_width="22px"
android:paddingLeft="2px"
android:paddingRight="2px"
android:paddingTop="2px"
android:layout_height="wrap_content"
/>
<TextView
android:id="@+id/label"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="40sp"
/>
</LinearLayout>
但图像不会从网络上显示。这段代码的顺序有问题。有人可以解决它吗？