如何在android中显示保存在sdcard文件夹中的图像

Question

当我正在显示保存在sdcard文件夹中的图像时,我找到了以下链接.

从SDCard在gridview中显示图像.

我使用以下代码从SD卡中的指定文件夹中获取图像,但在这里我得到0计数.

MyCode.jav

    String[] projection = {MediaStore.Images.Media._ID};

    final String[] columns = { MediaStore.Images.Media.DATA,MediaStore.Images.Media._ID };
    final String orderBy = MediaStore.Images.Media._ID;
    Cursor imagecursor = managedQuery( MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
            projection, 
            MediaStore.Images.Media.DATA + " like ? ",
            new String[] {"/my_images"},  
            null);
    int image_column_index = imagecursor.getColumnIndex(MediaStore.Images.Media._ID);
    this.count = imagecursor.getCount();
    this.thumbnails = new Bitmap[this.count];
    this.arrPath = new String[this.count];
    this.thumbnailsselection = new boolean[this.count];

    for (int i = 0; i < this.count; i++) {
        imagecursor.moveToPosition(i);
        int id = imagecursor.getInt(image_column_index);
        int dataColumnIndex = imagecursor
                .getColumnIndex(MediaStore.Images.Media.DATA);
        thumbnails[i] = MediaStore.Images.Thumbnails.getThumbnail(
                getApplicationContext().getContentResolver(), id,
                MediaStore.Images.Thumbnails.MICRO_KIND, null);
        arrPath[i] = imagecursor.getString(dataColumnIndex);
    }
    imageAdapter = new ImageAdapter();
    secure_gallery_grid.setAdapter(imageAdapter);
    imagecursor.close();

但是根据以下链接,所有保存在SD卡中的图像都在显示.但在这里我想显示保存在特定文件夹中的图像,就像我在该文件夹中创建了"My_images"文件夹和保存的图像一样.我想显示该文件夹中的图像,需要按照链接显示在gridview中.

Answer 1

您可以从particualr文件夹中获取文件的路径,如下所示

获得文件路径后,您可以在gridview中显示图像

ArrayList<String> f = new ArrayList<String>();// list of file paths
File[] listFile;

public void getFromSdcard()
{
    File file= new File(android.os.Environment.getExternalStorageDirectory(),"TMyFolder");

        if (file.isDirectory())
        {
            listFile = file.listFiles();


            for (int i = 0; i < listFile.length; i++)
            {

                f.add(listFile[i].getAbsolutePath());

            }
        }
}

请记住在清单文件中添加权限

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

具有写入权限默认情况下具有读取权限.

例

main.xml中

    <?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">

<GridView
    android:id="@+id/PhoneImageGrid"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:columnWidth="90dp"
    android:gravity="center"
    android:horizontalSpacing="10dp"
    android:numColumns="auto_fit"
    android:stretchMode="columnWidth"
    android:verticalSpacing="10dp" />

   </RelativeLayout>

gelleryitem.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">
<ImageView android:id="@+id/thumbImage" android:layout_width="wrap_content"
    android:layout_height="wrap_content" android:layout_centerInParent="true" />
<CheckBox android:id="@+id/itemCheckBox" android:layout_width="wrap_content"
    android:layout_height="wrap_content" android:layout_alignParentRight="true"
    android:layout_alignParentTop="true" />
    </RelativeLayout>

AndroidCustomGalleryActivity.java

   public class AndroidCustomGalleryActivity extends Activity {
private int count;
private Bitmap[] thumbnails;
private boolean[] thumbnailsselection;
private String[] arrPath;
private ImageAdapter imageAdapter;
ArrayList<String> f = new ArrayList<String>();// list of file paths
File[] listFile;


/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    getFromSdcard();
    GridView imagegrid = (GridView) findViewById(R.id.PhoneImageGrid);
    imageAdapter = new ImageAdapter();
    imagegrid.setAdapter(imageAdapter);


}
public void getFromSdcard()
{
    File file= new File(android.os.Environment.getExternalStorageDirectory(),"MapleBear");

        if (file.isDirectory())
        {
            listFile = file.listFiles();


            for (int i = 0; i < listFile.length; i++)
            {

                f.add(listFile[i].getAbsolutePath());

            }
        }
}

public class ImageAdapter extends BaseAdapter {
    private LayoutInflater mInflater;

    public ImageAdapter() {
        mInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    public int getCount() {
        return f.size();
    }

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

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

    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        if (convertView == null) {
            holder = new ViewHolder();
            convertView = mInflater.inflate(
                    R.layout.galleryitem, null);
            holder.imageview = (ImageView) convertView.findViewById(R.id.thumbImage);

            convertView.setTag(holder);
        }
        else {
            holder = (ViewHolder) convertView.getTag();
        }


        Bitmap myBitmap = BitmapFactory.decodeFile(f.get(position));
        holder.imageview.setImageBitmap(myBitmap);
        return convertView;
    }
}
class ViewHolder {
    ImageView imageview;


}
    }

快照