我已经设计了应用程序，我已经使用mulitiselectgridview进行图像选择。我的要求是我想限制用户选择最多8张图片，意味着每当用户试图查询第9个元素时它应该显示警告消息为弹出窗口，即可以选择最多8张图像，并且应该自动取消选中第9张图像。
public class MultiImagePicActivity extends Activity {
GridView mGrid;
private String[] arrPath,modifiedArrayPath;
private int ids[];
private int count;
int selectCount;
Activity act=this;
List<String> imagepaths;
int maximageselection;
//int sel=0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//now get Intent Extras
imagepaths=new ArrayList<String>();
imagepaths.clear();
loadApps();
setContentView(R.layout.grid_1);
mGrid = (GridView) findViewById(R.id.myGrid);
mGrid.setAdapter(new ImageAdapterxtends());
mGrid.setChoiceMode(GridView.CHOICE_MODE_MULTIPLE_MODAL);
mGrid.setMultiChoiceModeListener(new MultiChoiceModeListener());
}
private void loadApps() {
final String[] columns = { MediaStore.Images.Media.DATA, MediaStore.Images.Media._ID };
final String orderBy = MediaStore.Images.Media._ID;
Cursor imagecursor = getContentResolver().query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, columns, null, null, orderBy);
int image_column_index = imagecursor.getColumnIndex(MediaStore.Images.Media._ID);
this.count = imagecursor.getCount();
this.arrPath = new String[this.count];
ids = new int[count];
for (int i = 0; i <this.count; i++) {
imagecursor.moveToPosition(i);
ids[i] = imagecursor.getInt(image_column_index);
int dataColumnIndex = imagecursor.getColumnIndex(MediaStore.Images.Media.DATA);
arrPath[i] = imagecursor.getString(dataColumnIndex);
}
imagecursor.close();
}
@Override
public void onBackPressed() {
setResult(Activity.RESULT_CANCELED);
super.onBackPressed();
}
public class ImageAdapterxtends extends BaseAdapter{
CheckableLayout l;
ImageView i;
@Override
public int getCount() {
// TODO Auto-generated method stub
return arrPath.length;
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return arrPath[position];
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
if (convertView == null) {
i = new ImageView(MultiImagePicActivity.this);
i.setScaleType(ImageView.ScaleType.FIT_CENTER);
i.setLayoutParams(new ViewGroup.LayoutParams(50, 50));
l = new CheckableLayout(MultiImagePicActivity.this);
l.setLayoutParams(new GridView.LayoutParams(
GridView.LayoutParams.WRAP_CONTENT,
GridView.LayoutParams.WRAP_CONTENT));
l.addView(i);
} else {
l = (CheckableLayout) convertView;
i = (ImageView) l.getChildAt(0);
}
// Bitmap bmp = Utility.getResizedBitmap(BitmapFactory.decodeFile(arrPath[position]), 50, 50);
// i.setImageBitmap(bmp);
try {
setBitmap(i, ids[position]);
} catch (Throwable e) {
}
return l;
}
}
private void setBitmap(final ImageView iv,final int id) {
new AsyncTask<Void, Void, Bitmap>() {
Bitmap myBitmap;
@Override
protected Bitmap doInBackground(Void... params) {
return MediaStore.Images.Thumbnails.getThumbnail(getApplicationContext().getContentResolver(), id, MediaStore.Images.Thumbnails.MICRO_KIND, null);
}
@Override
protected void onPostExecute(Bitmap result) {
super.onPostExecute(result);
//iv.setImageBitmap(result);
setMyBitmap(result);
}
public final void setMyBitmap(Bitmap bitmap) {
if (this.myBitmap != null) {
this.myBitmap.recycle();
}
this.myBitmap = bitmap;
iv.getLayoutParams().height = 100;
iv.getLayoutParams().width = 100;
iv.setImageBitmap(myBitmap);
}
}.execute();
}
public class CheckableLayout extends FrameLayout implements Checkable {
private boolean mChecked;
public CheckableLayout(Context context) {
super(context);
}
public void setChecked(boolean checked) {
mChecked = checked;
setForeground(checked ? getResources().getDrawable(R.drawable.tr) : null);
}
public boolean isChecked() {
return mChecked;
}
public void toggle() {
//sel--;
selectCount--;
setChecked(!mChecked);
}
}
public class MultiChoiceModeListener implements
GridView.MultiChoiceModeListener {
public boolean onCreateActionMode(ActionMode mode, Menu menu) {
// Inflate the menu for the CAB
MenuInflater inflater = mode.getMenuInflater();
inflater.inflate(R.menu.context_menu, menu);
//return true;
mode.setTitle("Select Items");
mode.setSubtitle("One item selected");
return true;
}
public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
return true;
}
public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
// Respond to clicks on the actions in the CAB
switch (item.getItemId()) {
case R.id.menu_ok:
Intent i = new Intent();
modifiedArrayPath=imagepaths.toArray(new String[imagepaths.size()]);
i.putExtra("selectedImagepath", modifiedArrayPath);
//i.putExtra("data", selectedPath);
setResult(Activity.RESULT_OK, i);
//Toast.makeText(getApplicationContext(),String.valueOf(a),Toast.LENGTH_LONG).show();
//TODO do your stuff here
//mode.finish(); // Action picked, so close the CAB
act.finish();
return true;
default:
return false;
}
}
public void onDestroyActionMode(ActionMode mode) {
Toast.makeText(getApplicationContext(), "text", 1);
}
public void onItemCheckedStateChanged(ActionMode mode, int position,
long id, boolean checked) {
selectCount = mGrid.getCheckedItemCount();
if(checked){
imagepaths.add(arrPath[position]);
if(selectCount>8){
imagepaths.remove(arrPath[position]);
new AlertDialog.Builder(MultiImagePicActivity.this)
.setTitle("Restriction")
.setMessage("Max 8 images are allowed!!!")
.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// continue with delete
//finish();
dialog.dismiss();
}
})
.setIcon(android.R.drawable.ic_dialog_alert)
.show();
selectCount=maximageselection;
}
switch (selectCount) {
case 1:
mode.setSubtitle("One item selected");
break;
default:
mode.setSubtitle("" + selectCount + " items selected");
break;
}
}
else
imagepaths.remove(arrPath[position]);
}
}
}