如何获取日期并显示它？

Question

我有这个活动，其中第一个活动是显示SD卡中的图片并将其加载到gridview中。第二项活动是当你点击gridview中的图片时，它会显示图片的全尺寸。我想要什么是我的第二个活动，我还想显示被点击的图片的'约会'。如何获取日期并显示它。

这是我的第一个活动。

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); 

      } 
     }); 

这里是第二个活动

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，如果该文件在您的路径中，
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，然后去上次修改日期。

。

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("Dated : "+ dateString.toString()); //Dispaly dateString. You can do/use it your own way   
     } 
    } 
    catch 
    { 
    } 
    if(intf == null) 
    { 
     Date lastModDate = new Date(file.lastModified()); 
     Log.i("Dated : "+ lastModDate.toString());//Dispaly lastModDate. You can do/use it your own way 
    } 
}