Question

我有存储在SD卡中的图像，我在gridview中显示它，现在我想在gridview OnItemCLick Listener上显示全屏图像。我没有在下一个屏幕上显示全屏图像。只显示空白屏幕。

 public class MyMenu extends Activity{
    public class ImageAdapter extends BaseAdapter {
        private Context mContext;
        ArrayList<String> itemList = new ArrayList<String>();
        public ImageAdapter(Context c) {
            mContext = c; 
        }
        void add(String path){
            itemList.add(path); 
        }
        public int getCount() {
            return itemList.size();
        }
        public Object getItem(int arg0) {

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

            return position;
        }
        public View getView(int position, View convertView, ViewGroup parent) {
            ImageView imageView;
            if (convertView == null) {  // if it's not recycled, initialize some attributes
                imageView = new ImageView(mContext);
                imageView.setLayoutParams(new GridView.LayoutParams(90, 70));
                imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
                imageView.setPadding(8, 8, 8, 8);
            } else {
                imageView = (ImageView) convertView;
            }

            Bitmap bm = decodeSampledBitmapFromUri(itemList.get(position), 90, 70);
            imageView.setImageBitmap(bm);
            return imageView;
        }
        public Bitmap decodeSampledBitmapFromUri(String path, int reqWidth, int reqHeight) {

            Bitmap bm = null;
            // First decode with inJustDecodeBounds=true to check dimensions
            final BitmapFactory.Options options = new BitmapFactory.Options();
            options.inJustDecodeBounds = true;
            BitmapFactory.decodeFile(path, options);
            // Calculate inSampleSize
            options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
            // Decode bitmap with inSampleSize set
            options.inJustDecodeBounds = false;
            bm = BitmapFactory.decodeFile(path, options); 
            return bm;   
        }

        public int calculateInSampleSize(

                BitmapFactory.Options options, int reqWidth, int reqHeight) {
            // Raw height and width of image
            final int height = options.outHeight;
            final int width = options.outWidth;
            int inSampleSize = 1;

            if (height > reqHeight || width > reqWidth) {
                if (width > height) {
                    inSampleSize = Math.round((float)height / (float)reqHeight);    
                } else {
                    inSampleSize = Math.round((float)width / (float)reqWidth);    
                }   
            }
            return inSampleSize;    
        }
    }
    ImageAdapter myImageAdapter;
    private static final int CAMERA_REQUEST = 1888; 
    ImageButton camera,lib,baby,info;
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.mymenu);
        GridView gridview = (GridView) findViewById(R.id.gridview);
        gridview.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View v, int position,
                    long id) {
                Intent i5=new Intent(getApplicationContext(),FullScreenSd.class);
                i5.putExtra("id", position);
                startActivity(i5);
            }
        });
        myImageAdapter = new ImageAdapter(this);
        gridview.setAdapter(myImageAdapter);
        File folder = new File(Environment.getExternalStorageDirectory() + "/temp/");
        if (folder.exists()) {
            String ExternalStorageDirectoryPath = Environment
                    .getExternalStorageDirectory()
                    .getAbsolutePath();
            String targetPath = ExternalStorageDirectoryPath + "/temp/";
            File targetDirector = new File(targetPath);
            File[] files = targetDirector.listFiles();
            for (File file : files){
                myImageAdapter.add(file.getAbsolutePath());
            } 
        }

和接收类是，

image=(ImageView)findViewById(R.id.image);
        Intent i = getIntent();
        int resId = i.getExtras().getInt("id");
        image.setImageResource(resId);

Answer 1

i5.putExtra("id", position);

和

image.setImageResource(resId);

你到底在做什么？ position是它在gridview中的位置。你为什么把它当作身份？

Answer 2

您执行i5.putExtra("id", position);的部分是单击的元素的位置。这不是你需要的，你需要点击项目的resId。假设您已将resId存储在某个数组中，则应传递i5.putExtra("id", resIdArray[position]);

Answer 3

这个问题有四个解决方案，但前两个解决方案是正确的。

1）将位图转换为字节数组，然后传入活动。

将位图转换为字节数组： -

ByteArrayOutputStream stream = new ByteArrayOutputStream();
bmp.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[] byteArray = stream.toByteArray();

将字节数组传递给intent： -

Intent intent = new Intent(this, NextActivity.class);
intent.putExtra("picture", byteArray);
startActivity(intent);

从Bundle获取字节数组并转换为位图图像： -

Bundle extras = getIntent().getExtras();
byte[] byteArray = extras.getByteArray("picture");

Bitmap bmp = BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length);
ImageView image = (ImageView) findViewById(R.id.imageView1);

image.setImageBitmap(bmp);

2）首先将所选图像保存到内部或外部存储器中，然后将图像输入下一个活动并以全屏显示。

3）将Image Url传递给下一个活动，然后在全屏活动中再次下载图像，然后在imageview中显示。

4）将位图传递给活动。（但如果你的图像尺寸太大，那么这个解决方案就不起作用了）

显示全屏图像

3 个答案: