android imageswitcher gallery 根据数据库内图片名字进行查看/删除

layout/imageswitch.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <ImageSwitcher
        android:id="@+id/arc_hf_img_switcher"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true" />

    <LinearLayout
        android:id="@+id/linearLayout1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:gravity="center" >

        <Gallery
            android:id="@+id/arc_hf_img_gallery"
            android:layout_width="fill_parent"
            android:layout_height="60dp"
            android:layout_weight="1"
            android:background="#55000000"
            android:gravity="center_vertical"
            android:spacing="16dp" />

        <Button
            android:id="@+id/arc_hf_img_btnDel"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginRight="30dp"
            android:text="@string/arc_hf_img_btnDel" />

        <Button
            android:id="@+id/arc_hf_img_btnBack"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginRight="30dp"
            android:text="@string/arc_hf_img_btnBack" />
    </LinearLayout>

</RelativeLayout>

ImgSwitch.java

public class ImgSwitch extends Activity implements OnItemSelectedListener,
        ViewFactory {
    private final String DATABASE_PATH = Environment
            .getExternalStorageDirectory().getAbsolutePath() + "/hfdatabase";
    private final String DATABASE_FILENAME = "hf_database.db";
    private final String TABLE_NAME = "HF_IMG_THEME";
    private final String strImgPath = Environment.getExternalStorageDirectory()
            .toString() + "/dlion/";// 存放照片的文件夹
    private SQLiteDatabase db;
    private ImageSwitcher is;
    private Gallery gallery;
    private Bitmap[] bitmaps;
    private int[] _ids;
    private String[] imgNames;
    private int parentId;
    public int gPosition = 0;
    private int isPosition = 0;
    private Button btnDel;
    private Button btnBack;

    // 返回键监听，添加关闭数据库功能。
    public void onBackPressed() {
        super.onBackPressed();
        db.close();
        finish();
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.imageswitch);
        db = openDatabase();
        parentId = this.getIntent().getIntExtra("parentId", 0);

        gallery = (Gallery) findViewById(R.id.arc_hf_img_gallery);
        is = (ImageSwitcher) findViewById(R.id.arc_hf_img_switcher);
        is.setFactory(this);

        is.setInAnimation(AnimationUtils.loadAnimation(this,
                android.R.anim.fade_in));
        is.setOutAnimation(AnimationUtils.loadAnimation(this,
                android.R.anim.fade_out));

        btnDel = (Button) findViewById(R.id.arc_hf_img_btnDel);
        btnBack = (Button) findViewById(R.id.arc_hf_img_btnBack);
        btnDel.setOnClickListener(new btnListener());
        btnBack.setOnClickListener(new btnListener());

        initImgs();
    }

    // 按键监听
    class btnListener implements OnClickListener {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            switch (v.getId()) {
            case R.id.arc_hf_img_btnBack:
                db.close();
                finish();
                break;
            case R.id.arc_hf_img_btnDel:
                db.delete(TABLE_NAME, "_id=" + _ids[gPosition], null);
                File file = new File(imgNames[gPosition]);
                file.delete();
                Toast.makeText(ImgSwitch.this, imgNames[gPosition] + "删除成功",
                        Toast.LENGTH_SHORT).show();
                initImgs();
                break;
            default:
                break;
            }
        }

    }

    // 初始化图片视图
    private void initImgs() {
        Cursor cursorImgName = db.query(TABLE_NAME, null, "parentId = "
                + parentId, null, null, null, null);
        bitmaps = new Bitmap[cursorImgName.getCount()];
        imgNames = new String[cursorImgName.getCount()];
        _ids = new int[cursorImgName.getCount()];

        // 优化内存
        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inSampleSize = 20;
        for (int i = 0; i < cursorImgName.getCount(); i++) {
            cursorImgName.moveToNext();
            
            // 保存图片组名字、ID、完整路径
            imgNames[i] = strImgPath
                    + cursorImgName.getString(cursorImgName
                            .getColumnIndex("imgName"));
            _ids[i] = cursorImgName.getInt(cursorImgName.getColumnIndex("_id"));
            bitmaps[i] = BitmapFactory.decodeFile(imgNames[i], options);
        }
        gallery.setAdapter(new ImageAdapter(this));
        gallery.setOnItemSelectedListener(this);
        if (gPosition == cursorImgName.getCount()
                && cursorImgName.getCount() >= 1) {
            is.setImageURI(Uri.parse(imgNames[isPosition - 1]));
        } else if (cursorImgName.getCount() == 0) { // 没有图片时，取消删除键监听
            btnDel.setEnabled(false);
        }
    }

    @Override
    public View makeView() {
        // TODO Auto-generated method stub
        ImageView i = new ImageView(this);
        i.setBackgroundColor(0xFF000000);
        i.setScaleType(ImageView.ScaleType.FIT_CENTER);
        i.setLayoutParams(new ImageSwitcher.LayoutParams(
                LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
        return i;
    }

    // 覆写baseadapter类
    public class ImageAdapter extends BaseAdapter {
        private Context mContext;

        public ImageAdapter(Context c) {
            mContext = c;
        }

        @Override
        public int getCount() {
            // TODO Auto-generated method stub
            return bitmaps.length;
        }

        @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(int position, View convertView, ViewGroup parent) {
            // TODO Auto-generated method stub
            gPosition = position;
            ImageView i = new ImageView(mContext);

            i.setImageBitmap(bitmaps[position]);
            i.setAdjustViewBounds(true);
            i.setLayoutParams(new Gallery.LayoutParams(
                    LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
            return i;
        }
    }

    @Override
    public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2,
            long arg3) {
        // TODO Auto-generated method stub
        isPosition = arg2;
        is.setImageURI(Uri.parse(imgNames[arg2]));
    }

    @Override
    public void onNothingSelected(AdapterView<?> arg0) {
        // TODO Auto-generated method stub

    }

    // 初始化数据库
    private SQLiteDatabase openDatabase() {
        try {
            String databaseFilename = DATABASE_PATH + "/" + DATABASE_FILENAME;
            File dir = new File(DATABASE_PATH);
            if (!dir.exists())
                dir.mkdir();

            if (!(new File(databaseFilename)).exists()) {
                InputStream is = getResources().openRawResource(
                        R.raw.hf_database);
                FileOutputStream fos = new FileOutputStream(databaseFilename);
                byte[] buffer = new byte[8192];
                int count = 0;
                // 开始复制hf_database.db文件
                while ((count = is.read(buffer)) > 0) {
                    fos.write(buffer, 0, count);
                }
            }

            db = SQLiteDatabase.openOrCreateDatabase(databaseFilename, null);
            return db;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

}