new AlertDialog.Builder(v.getContext()).setMessage("msg to display!").show();

    LayoutInflater inflater = LayoutInflater.from(HistoryActivity.this);
    final View vv = inflater.inflate(R.layout.dialog_processing_tts, null);
    final AlertDialog.Builder alert = new AlertDialog.Builder(
            HistoryActivity.this);
    alert.setTitle("Delete");
    alert.setView(vv);
    alert.setCancelable(false)
            .setPositiveButton("Delete", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    databaseHelperClass.deleteHistory(list.get(position).getID());
                    list.clear();
                    setAdapterForList();

                }
            })
            .setNegativeButton("Cancel",
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int id) {
                            dialog.cancel();
                        }
                    });

    final AlertDialog dialog = alert.create();
    dialog.show();

只是当你想解散对话框时要小心——使用dialog.dismiss()。在我的第一次尝试中，我使用了遣散dialog(0)(我可能从某个地方复制)，有时它可以工作。使用系统提供的对象听起来是更安全的选择。

// Dialog box

public void dialogBox() {
    AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
    alertDialogBuilder.setMessage("Click on Image for tag");
    alertDialogBuilder.setPositiveButton("Ok",
        new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface arg0, int arg1) {
        }
    });

    alertDialogBuilder.setNegativeButton("cancel",
        new DialogInterface.OnClickListener() {

        @Override
        public void onClick(DialogInterface arg0, int arg1) {

        }
    });

    AlertDialog alertDialog = alertDialogBuilder.create();
    alertDialog.show();
}

     new AlertDialog.Builder(loginregister.this)
            .setTitle("messege")
            .setPositiveButton("ok", null)
            .setMessage( "user name : " + username + "/n" +
                            "password :" + password + "/n"  )
    .show();

public void showSimpleDialog(View view) {
    // Use the Builder class for convenient dialog construction
    AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
    builder.setCancelable(false);
    builder.setTitle("AlertDialog Title");
    builder.setMessage("Simple Dialog Message");
    builder.setPositiveButton("OK!!!", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int id) {
            //
        }
    })
    .setNegativeButton("Cancel ", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {

        }
    });

    // Create the AlertDialog object and return it
    builder.create().show();
}

也可以看看我的关于Android对话的博客，你会在这里找到所有的细节:http://www.fahmapps.com/2016/09/26/dialogs-in-android-part1/。