android - 如何获取拍摄日期并显示它？

Question

我有这个 Activity ，其中第一个 Activity 是显示 sdcard 中的图片并将其加载到 gridview 中。第二个 Activity 是当您单击 gridview 中的图片时，它将显示图像的完整尺寸。我想要的是我的第二个 Activity ，我还想显示被点击照片的“拍摄日期”。如何获取拍摄日期并显示。

这是我的第一个 Activity 。

public class MainActivity 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);
    }

    @Override
    public int getCount() {
        return itemList.size();
    }

    @Override
    public Object getItem(int arg0) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    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(220, 220));
            imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
            imageView.setPadding(8, 8, 8, 8);
        } else {
            imageView = (ImageView) convertView;
        }

        Bitmap bm = decodeSampledBitmapFromUri(itemList.get(position), 220,
                220);

        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;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    GridView gridview = (GridView) findViewById(R.id.gridview);
    myImageAdapter = new ImageAdapter(this);
    gridview.setAdapter(myImageAdapter);

    String ExternalStorageDirectoryPath = Environment
            .getExternalStorageDirectory().getAbsolutePath();

    String targetPath = ExternalStorageDirectoryPath + "/test/";

    Toast.makeText(getApplicationContext(), targetPath, Toast.LENGTH_LONG)
            .show();
    File targetDirector = new File(targetPath);

    File[] files = targetDirector.listFiles();
    for (File file : files) {
        myImageAdapter.add(file.getAbsolutePath());
    }
}

gridview.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View v,
                    int position, long id) {

ImageView img = myImageAdapter.getView(position, v, parent);
                img.buildDrawingCache(); 
                Bitmap bmap = img.getDrawingCache();
                Intent intent = new Intent(MainActivity.this,
                        Imageviewer.class);
                Bundle bundle = new Bundle();
                    String par=myimageadpter.getpath(position);
                             bundle.putString("imagepath", par);
                intent.putExtras(bundle);
                startActivityForResult(intent, 0);

            }
        });

这是第二个 Activity

public class ImageViewer extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);


    Bundle bundle = this.getIntent().getExtras();

    String s=bundle.getString("imagepath");
    Bitmap Imagefrompath = BitmapFactory.decodeFile(s);
            ImageView img=(ImageView) findViewById(R.id.imageView1);
            img.setImageBitmap(Imagefrompath );


}

}

Answer 1

1. 检查文件是否存在于你的路径中，
2. 尝试获取文件创建日期(如果可用)
3. 如果创建日期不可用，则转到上次修改日期。

.

File file = new File(filePath);
if(file.exists()) //Extra check, Just to validate the given path
{
    ExifInterface intf = null;
    try 
    {
        intf = new ExifInterface(filePath);
        if(intf != null)
        {
            String dateString = intf.getAttribute(ExifInterface.TAG_DATETIME);
            Log.i("PHOTO DATE", "Dated : "+ dateString); //Display dateString. You can do/use it your own way        
        }
    }
    catch (IOException e)
    {
    }
    if(intf == null)
    {
        Date lastModDate = new Date(file.lastModified());
        Log.i("PHOTO DATE", "Dated : "+ lastModDate.toString());//Dispaly lastModDate. You can do/use it your own way
    }
}