android 加载图片到gallery

/** == XML Layout ==
*
* <?xml version=\"1.0\" encoding=\"utf-8\"?>
* <LinearLayout xmlns:android=\"http://schemas.android.com/apk/res/android\"
* android:orientation=\"vertical\"
* android:layout_width=\"fill_parent\"
* android:layout_height=\"fill_parent\"
* >
* <Gallery id=\"@+id/gallery\"
* android:layout_width=\"fill_parent\"
* android:layout_height=\"wrap_content\"
* android:gravity=\"bottom\"
* />
* </LinearLayout>
*
*/

package org.anddev.android.galleryexample;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageView;

public class GalleryExample extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.main);

/* Find the gallery defined in the main.xml
* Apply a new (custom) ImageAdapter to it. */
((Gallery) findViewById(R.id.gallery))
.setAdapter(new ImageAdapter(this));
}

public class ImageAdapter extends BaseAdapter {
/** The parent context */
private Context myContext;

/** URL-Strings to some remote images. */
private String[] myRemoteImages = {
\"http://www.anddev.org/images/tiny_tutheaders/weather_forecast.png\",
\"http://www.anddev.org/images/tiny_tutheaders/cellidtogeo.png\",
\"http://www.anddev.org/images/tiny_tutheaders/droiddraw.png\"
};

/** Simple Constructor saving the \'parent\' context. */
public ImageAdapter(Context c) { this.myContext = c; }

/** Returns the amount of images we have defined. */
public int getCount() { return this.myRemoteImages.length; }

/* Use the array-Positions as unique IDs */
public Object getItem(int position) { return position; }
public long getItemId(int position) { return position; }

/** Returns a new ImageView to
* be displayed, depending on
* the position passed. */
public View getView(int position, View convertView, ViewGroup parent) {
ImageView i = new ImageView(this.myContext);

try {
/* Open a new URL and get the InputStream to load data from it. */
URL aURL = new URL(myRemoteImages[position]);
URLConnection conn = aURL.openConnection();
conn.connect();
InputStream is = conn.getInputStream();
/* Buffered is always good for a performance plus. */
BufferedInputStream bis = new BufferedInputStream(is);
/* Decode url-data to a bitmap. */
Bitmap bm = BitmapFactory.decodeStream(bis);
bis.close();
is.close();
/* Apply the Bitmap to the ImageView that will be returned. */
i.setImageBitmap(bm);
} catch (IOException e) {
i.setImageResource(R.drawable.error);
Log.e(\"DEBUGTAG\", \"Remtoe Image Exception\", e);
}

/* Image should be scaled as width/height are set. */
i.setScaleType(ImageView.ScaleType.FIT_CENTER);
/* Set the Width/Height of the ImageView. */
i.setLayoutParams(new Gallery.LayoutParams(150, 150));
return i;
}

/** Returns the size (0.0f to 1.0f) of the views
* depending on the \'offset\' to the center. */
public float getScale(boolean focused, int offset) {
/* Formula: 1 / (2 ^ offset) */
return Math.max(0, 1.0f / (float)Math.pow(2, Math.abs(offset)));
}
}
}

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