Android 控件之Gallery图片集

Gallery是Android中的图片库控件。先看效果，爽一番

一、简介

在中心锁定，水平显示列表的项。

二、实例

1.布局文件

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

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
    <Gallery android:id="@+id/gallery1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center_vertical"
        android:spacing="16dp"
    />
</LinearLayout>

</LinearLayout>

2.属性文件

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="TogglePrefAttrs">
        <attr name="android:preferenceLayoutChild" />
    </declare-styleable>
    
    <!-- These are the attributes that we want to retrieve from the theme
         in view/Gallery1.java -->
    <declare-styleable name="Gallery1">
        <attr name="android:galleryItemBackground" />
    </declare-styleable>
    
     <declare-styleable name="LabelView">
        <attr name="text" format="string" />
        <attr name="textColor" format="color" />
        <attr name="textSize" format="dimension" />
    </declare-styleable>
</resources>

3.代码

/**
 * 
 */
package wjq.WidgetDemo;

import android.R.layout;
import android.app.Activity;
import android.content.Context;
import android.content.res.TypedArray;
import android.database.Cursor;
import android.os.Bundle;
import android.provider.Contacts.People;
import android.view.ContextMenu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.view.ContextMenu.ContextMenuInfo;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageView;
import android.widget.SimpleCursorAdapter;
import android.widget.SpinnerAdapter;
import android.widget.Toast;
import android.widget.AdapterView.AdapterContextMenuInfo;

public class GalleryDemo extends Activity {
    private Gallery gallery;
    private Gallery gallery1;
    /*
     * (non-Javadoc)
     * 
     * @see android.app.Activity#onCreate(android.os.Bundle)
     */
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.gallerypage);
        gallery = (Gallery) findViewById(R.id.gallery);
        gallery.setAdapter(new ImageAdapter(this));
  
        registerForContextMenu(gallery);
  
        Cursor c = getContentResolver().query(People.CONTENT_URI, null, null, null, null);
        startManagingCursor(c);
         
        SpinnerAdapter adapter = new SimpleCursorAdapter(this,
        // Use a template that displays a text view
                android.R.layout.simple_gallery_item,
                // Give the cursor to the list adatper
                c,
                // Map the NAME column in the people database to...
                new String[] {People.NAME},
                // The "text1" view defined in the XML template
                new int[] { android.R.id.text1 });
        gallery1= (Gallery) findViewById(R.id.gallery1);
        gallery1.setAdapter(adapter);
    }

    @Override
    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
        menu.add("Action");
    }

    @Override
    public boolean onContextItemSelected(MenuItem item) {
        AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();
        Toast.makeText(this, "Longpress: " + info.position, Toast.LENGTH_SHORT).show();
        return true;
    }
 
    public class ImageAdapter extends BaseAdapter {
        int mGalleryItemBackground;
        private Context mContext;
        private Integer[] mImageIds = { R.drawable.b, R.drawable.c, R.drawable.d, R.drawable.f, R.drawable.g };
        public ImageAdapter(Context context) {
            mContext = context;
            TypedArray a = obtainStyledAttributes(R.styleable.Gallery1);
            mGalleryItemBackground = a.getResourceId(R.styleable.Gallery1_android_galleryItemBackground, 0);
            a.recycle();
        }

        @Override
        public int getCount() {
            return mImageIds.length;
        }

        @Override
        public Object getItem(int position) {
            return position;
        }

        @Override
        public long getItemId(int position) {
            return position;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            ImageView i = new ImageView(mContext);
            i.setImageResource(mImageIds[position]);
            i.setScaleType(ImageView.ScaleType.FIT_XY);
            i.setLayoutParams(new Gallery.LayoutParams(300, 400));
            // The preferred Gallery item background
            i.setBackgroundResource(mGalleryItemBackground);
            return i;
        }
    }

}