Android:ProgressDialog 未显示在适配器类中

Question

在我的应用程序中，我有一个 ListView ，每个项目都有一个按钮。如果用户单击按钮，我想执行一些 http 连接。所以我在 Adapter 类中使用 AsyncTask。现在的问题是进度对话框没有显示。

private class MyClass extends AsyncTask<Void, Long, Boolean> {
        private Context context;
        private ServerCall call = new ServerCall();
        private ProgressDialog progressDialog1;

        public MyClass(Context context) {
            this.context = context;
        }

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            try {
                progressDialog1 = ProgressDialog.show(context, "",
                        "Please wait...", true);
                progressDialog1.setIndeterminate(true);

            } catch (final Throwable th) {

            }

        }

        @Override
        protected void onProgressUpdate(Long... values) {

            super.onProgressUpdate(values);
        }

        @Override
        protected Boolean doInBackground(Void... params) {
            //some tasks

            return true;
        }

        @Override
        protected void onPostExecute(Boolean result) {
            if (mode.equalsIgnoreCase("History")) {

                Intent order = new Intent(context, ActicityA.class);
                order.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                context.startActivity(order);

            } else {
                Intent order = new Intent(context, ActivityB.class);
                order.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                context.startActivity(order);
            }

        }
    }

Answer 1

试试这个'

protected void onPreExecute() {
        dialog = new ProgressDialog(Activity.this);
        dialog.setMessage("Please wait...");
        dialog.setIndeterminate(true);
        //dialog.setCancelable(false);
        dialog.show();
    }