我有，我想实现一个图片库与一个GridView的要求。 我尝试使用您好库在Android开发者网站。但GridView控件无法正常工作。

I have a requirement in that I want to implement an image gallery with a GridView. I tried using Hello gallery on the Android developer website. But the GridView doesn't work.

推荐答案

使用该XML的布局：gallery.xml

Use this XML for Layout : gallery.xml

<?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" android:background="@drawable/bg_child">

    <FrameLayout android:id="@+id/FrameLayout01"
        android:layout_width="fill_parent" android:layout_height="fill_parent">
        <FrameLayout android:id="@+id/LinearLayout01"
            android:layout_gravity="top" android:layout_height="50dp" android:layout_width="fill_parent">
            <TextView android:id="@+id/TextView01"
                android:layout_width="wrap_content" android:layout_height="wrap_content" android:textStyle="bold" android:layout_gravity="center_vertical" android:layout_marginLeft="30dp" android:gravity="center_vertical" android:drawableLeft="@drawable/photo_frame" android:textColor="@color/grey" android:text="@string/photogallery_txt"></TextView>
            <Button android:layout_gravity="right" android:id="@+id/btnMoreInfo" android:layout_marginRight="5dp" android:layout_marginTop="5dp" android:textStyle="bold" android:background="@drawable/my_child_button" android:layout_width="100dp" android:layout_height="40dp" android:text="@string/moreinfo_txt"></Button>
        </FrameLayout>
        <GridView xmlns:android="http://schemas.android.com/apk/res/android"
            android:id="@+id/gridview" android:layout_width="fill_parent"
            android:layout_height="fill_parent" android:columnWidth="90dp"
            android:numColumns="auto_fit" android:verticalSpacing="10dp"
            android:horizontalSpacing="10dp" android:stretchMode="columnWidth"
            android:gravity="center" android:layout_gravity="bottom"
            android:layout_marginTop="50dp"></GridView>
    </FrameLayout>
</LinearLayout>

活动文件GalleryPage.java

Activity File GalleryPage.java

public class GalleryPage extends Activity {

    // private Integer[] mImageIds = {R.drawable.splash, R.drawable.splash,
    // R.drawable.splash, R.drawable.splash, R.drawable.splash,
    // R.drawable.splash, R.drawable.splash};

    private static Uri[] mUrls = null;
    private static String[] strUrls = null;
    private String[] mNames = null;
    private GridView gridview = null;
    private Cursor cc = null;
    private Button btnMoreInfo = null;
    private ProgressDialog myProgressDialog = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);

        CommonFunctions.setLanguage(getBaseContext());

        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.gallery);
        btnMoreInfo = (Button) findViewById(R.id.btnMoreInfo);
        // It have to be matched with the directory in SDCard
        cc = this.getContentResolver().query(
                MediaStore.Images.Media.EXTERNAL_CONTENT_URI, null, null, null,
                null);

        // File[] files=f.listFiles();
        if (cc != null) {

            myProgressDialog = new ProgressDialog(GalleryPage.this);
            myProgressDialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
            myProgressDialog.setMessage(getResources().getString(R.string.pls_wait_txt));
            //myProgressDialog.setIcon(R.drawable.blind);
            myProgressDialog.show();

            new Thread() {
                public void run() {
                    try {
                        cc.moveToFirst();
                        mUrls = new Uri[cc.getCount()];
                        strUrls = new String[cc.getCount()];
                        mNames = new String[cc.getCount()];
                        for (int i = 0; i < cc.getCount(); i++) {
                            cc.moveToPosition(i);
                            mUrls[i] = Uri.parse(cc.getString(1));
                            strUrls[i] = cc.getString(1);
                            mNames[i] = cc.getString(3);
                            //Log.e("mNames[i]",mNames[i]+":"+cc.getColumnCount()+ " : " +cc.getString(3));
                        }

                    } catch (Exception e) {
                    }
                    myProgressDialog.dismiss();
                }
            }.start();
         gridview = (GridView) findViewById(R.id.gridview);
         gridview.setAdapter(new ImageAdapter(this));

         gridview.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View v,
                  int position, long id) {
               Intent i = new Intent(GalleryPage.this, BigImage.class);
               Log.e("intent : ", ""+position);
               i.putExtra("imgUrls", strUrls);
               i.putExtra("position", position);
               startActivity(i);
            }
         });

        }

        btnMoreInfo.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                Intent i = new Intent(GalleryPage.this, ChildLogin.class);
                startActivity(i);
            }
        });
    }

    /**
     * This class loads the image gallery in grid view.
     *
     */
    public class ImageAdapter extends BaseAdapter {
        private Context mContext;

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

        public int getCount() {
            return cc.getCount();
        }

        public Object getItem(int position) {
            return null;
        }

        public long getItemId(int position) {
            return 0;
        }

        // create a new ImageView for each item referenced by the Adapter
        public View getView(int position, View convertView, ViewGroup parent) {
            View v = convertView;
            LayoutInflater vi = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            v = vi.inflate(R.layout.galchild, null);

            try {

                ImageView imageView = (ImageView) v.findViewById(R.id.ImageView01);
                //imageView.setScaleType(ImageView.ScaleType.FIT_XY);
                // imageView.setPadding(8, 8, 8, 8);
                Bitmap bmp = decodeURI(mUrls[position].getPath());
                //BitmapFactory.decodeFile(mUrls[position].getPath());
                imageView.setImageBitmap(bmp);
                //bmp.
                TextView txtName = (TextView) v.findViewById(R.id.TextView01);
                txtName.setText(mNames[position]);
            } catch (Exception e) {

            }
            return v;
        }
    }

    @Override
    protected void onStart() {
        // TODO Auto-generated method stub
        super.onStart();
        FlurryAgent.onStartSession(this, "***");
    }
    // @Override
    // protected void onStop() {
    // TODO Auto-generated method stub
    // super.onStop();
    // FlurryAgent.onEndSession(this);

    // }

    /**
     * This method is to scale down the image 
     */
    public Bitmap decodeURI(String filePath){

        Options options = new Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(filePath, options);

        // Only scale if we need to 
        // (16384 buffer for img processing)
        Boolean scaleByHeight = Math.abs(options.outHeight - 100) >= Math.abs(options.outWidth - 100);
        if(options.outHeight * options.outWidth * 2 >= 16384){
            // Load, scaling to smallest power of 2 that'll get it <= desired dimensions
            double sampleSize = scaleByHeight
                ? options.outHeight / 100
                : options.outWidth / 100;
            options.inSampleSize = 
                (int)Math.pow(2d, Math.floor(
                Math.log(sampleSize)/Math.log(2d)));
        }

        // Do the actual decoding
        options.inJustDecodeBounds = false;
        options.inTempStorage = new byte[512];  
        Bitmap output = BitmapFactory.decodeFile(filePath, options);

        return output;
    }
}