java - 如果包含其他数据则显示列表 AlertDialog

Question

1. 在 LoginActivity 中显示单个按钮
2. 并且想要启动 UploadActivity，如果UploadActivity 的列表包含任何其他数据，则显示警告“在 UploadActivity 中找不到图像”

简而言之，如果上传 Activity 在列表中没有数据，我只想显示警报对话框，否则启动 UploadActivity...

btnCheckUpload.setOnClickListener(new OnClickListener() {

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub


                    AlertDialog.Builder alertdialog = new AlertDialog.Builder(LoginActivity.this);
                    alertdialog.setTitle(getResources().getString(R.string.app_name));
                    alertdialog.setMessage("No Images found in UploadActivity");
                    alertdialog.setPositiveButton("OK", new DialogInterface.OnClickListener() 
                    {
                        public void onClick(DialogInterface dialog, int which) {
                            // TODO Auto-generated method stub
                            }
                        });
                    alertdialog.show();
                    }
                }
            });

UploadActivity.java:-

    public class UploadActivity extends Activity  {

            final private static int DIALOG_LOGIN = 1;
            EditText editPersonName, editPersonaEmail, editPersonTelephone, parental_email ;
            TextView editImageName ;
            String fileName;

            static ListView lstView;
            private Handler handler = new Handler();;

            static List <String> ImageList;
            String strPath;

            CheckBox chkOption3;

            TextView tv1, tv2;
            CheckBox chkOption1, chkOption2 ;

            int position ;

            static File f1;

            static String folder = null ;

            Intent i;
            Intent intent ;

            TextView textHeading1;

            static File[] files;
            static File  file ;

            static List <String> it ;

            static String textHeading = null;
            // new Class DB
            final myDBClasss myDb = new myDBClasss(this);

            @Override
            public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);      

            setContentView(R.layout.activity_upload);

            textHeading1 = (TextView) findViewById(R.id.txtEventNameDate1);
            textHeading1.setText(CameraLauncherActivity.folder);


            /*** Get Images from SDCard ***/
            ImageList = getSD();

            // ListView and imageAdapter
            lstView = (ListView) findViewById(R.id.listView1);
            lstView.setAdapter(new ImageAdapter(this));              
            }


            public static List <String> getSD()
            {
            it = new ArrayList <String>();
            String string = "/mnt/sdcard/Pictures/Awesome/";
    f1 = new File (string+ CameraLauncherActivity.folder+ "/");
            files = f1.listFiles ();

            for (int i = 0; i < files.length; i++)
            {
            file = files[i];
            Log.d("Count",file.getPath());
            it.add (file.getPath());
            }
            return it;
            }


            public class ImageAdapter extends BaseAdapter
            {
            private Context context;

            public ImageAdapter(Context c)
            {
            // TODO Auto-generated method stub
            context = c;
            }

            public int getCount() {
            // TODO Auto-generated method stub
            return ImageList.size();
            }

            public Object getItem(int position) {
            // TODO Auto-generated method stub
            return position;
            }

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

            public View getView(final int position, View convertView, ViewGroup parent) {
            // TODO Auto-generated method stub

            LayoutInflater inflater = (LayoutInflater) context
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);              

            if (convertView == null) {
            convertView = inflater.inflate(R.layout.list_upload, null);
            }              

            // ColImgName
            TextView txtName = (TextView) convertView.findViewById(R.id.ColImgName);
            strPath = ImageList.get(position).toString();

            // Get File Name
            fileName = strPath.substring( strPath.lastIndexOf('/')+1, strPath.length() );
            file = new File(strPath);
            @SuppressWarnings("unused")
            long length = file.length();
            txtName.setText(fileName);

            // Image Resource
            ImageView imageView = (ImageView) convertView.findViewById(R.id.ColImgPath);
            final BitmapFactory.Options options = new BitmapFactory.Options();

            options.inSampleSize = 8;

            Bitmap bm = BitmapFactory.decodeFile(strPath,options);
            imageView.setImageBitmap(bm);


            // ColStatus
            final ImageView txtStatus = (ImageView) convertView.findViewById(R.id.ColStatus);
            txtStatus.setImageResource(R.drawable.bullet_button);

            // progressBar
            final ProgressBar progress = (ProgressBar) convertView.findViewById(R.id.progressBar);
            progress.setVisibility(View.GONE);

            //btnUpload
            final ImageButton btnUpload = (ImageButton) convertView.findViewById(R.id.btnUpload);
            btnUpload.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
            // Upload
            btnUpload.setEnabled(false);

            startUpload(position);
            }
            });


            return convertView;

            }      
    }

Answer 1

lstView.getChildCount() 将返回组中 child 的数量。这是您查看的。因此存储您的 ImageAdapter 的引用然后使用 adapter.getcount();

您还可以检查您的 ImageList 大小。

代替

if (UploadActivity.lstView.getChildCount() > 0)

使用

if (imageList.size) > 0)

或者if (adapter.getcount() > 0)