Question

像往常一样，我担心我会因此而陷入困境。

我已经成功修改了一个教程，从SDCard上的文件夹中获取一组图像，以便在GridView中显示

我尝试做的是允许用户选择一个设置为壁纸。

我的问题是，我知道图片的文件夹位置必须已经收到才能显示我无法弄清楚如何获取它然后将其设置为壁纸。

我已经包含了我的多次尝试中的一小部分，但是当我尝试从galleryitem.xml文件访问ImageView时，它会抛出所有类型的错误，主要是NullPointers。

 public class MyWallpapers extends Activity {


private boolean[] thumbnailsselection;
private String[] arrPath;
private ImageAdapter imageAdapter;

ImageView Selected;


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.wallpaper_view_activity);


    getFromSdcard();
    GridView imagegrid = (GridView) findViewById(R.id.PhoneImageGrid);
    imageAdapter = new ImageAdapter();
    imagegrid.setAdapter(imageAdapter);


    final ImageView Selected = (ImageView) findViewById(R.id.thumbImage);
      Selected.setOnClickListener(new OnClickListener() {

          public void onClick(View v) {


              //need to get the position of the file and set it as wallpaper when the user clicks the image

              Context context = this.getAbsolutePath();
              Bitmap mBitmap = BitmapFactory.decodeResource(getResources(),
                      mImageIds[pos]);
              context.setWallpaper(context);

          }
      });
  }



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

        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;


}
    }

这是我在wallpaper_view_activity.xml中的GridView

<?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:layout_above="@+id/button1"
    android:columnWidth="90dp"
    android:gravity="center"
    android:horizontalSpacing="10dp"
    android:numColumns="auto_fit"
    android:stretchMode="columnWidth"
    android:verticalSpacing="10dp" />

最后是galleryitem.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" />

对此的任何帮助都将一如既往地非常感谢

Answer 1

ImageLocation = listFile[position].getAbsolutePath();

                            BitmapFactory.Options options = new BitmapFactory.Options();
                            options.inPreferredConfig = Bitmap.Config.ARGB_8888;
                            Bitmap bitmap = BitmapFactory.decodeFile(ImageLocation, options);


                            WallpaperManager myWallpaperManager 
                            = WallpaperManager.getInstance(getApplicationContext());
                            try {
                                myWallpaperManager.setBitmap(bitmap);
                                Toast.makeText(MyWallpapers.this, "Wallpaper Set", Toast.LENGTH_SHORT).show();
                            } catch (IOException e) {
                                Toast.makeText(MyWallpapers.this, "Error", Toast.LENGTH_SHORT).show();
                                e.printStackTrace();
                            }

Android从gridview图像设置壁纸

1 个答案: