Activity的基类

public class BaseAcitivity extends Activity {

private AlertDialog alertDialog;

public void showLoadingDialog() {

alertDialog = new AlertDialog.Builder(this).create();

alertDialog.getWindow().setBackgroundDrawable(new ColorDrawable());

alertDialog.setCancelable(false);

alertDialog.show();

alertDialog.setContentView(R.layout.loading_alert);

alertDialog.setCanceledOnTouchOutside(false);

}

public void dismissLoadingDialog() {

if (null != alertDialog && alertDialog.isShowing()) {

alertDialog.dismiss();

}

}

}

XML：loading_alert

android:layout_width="match_parent"

android:layout_height="match_parent"

android:background="@android:color/transparent">

style="@style/AppTheme.NoActionBar"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_centerHorizontal="true"

android:layout_centerVertical="true"

android:layout_gravity="center_horizontal" />

在styles.xml中添加

false

true