<?xmlversion="1.0"encoding="utf-8"?><RelativeLayoutxmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"android:layout_width="match_parent"android:layout_height="match_parent"android:paddingBottom="@dimen/activity_vertical_margin"android:paddingLeft="@dimen/activity_horizontal_margin"android:paddingRight="@dimen/activity_horizontal_margin"android:paddingTop="@dimen/activity_vertical_margin"tools:context="com.example.liang.at.pa"><Buttonandroid:id="@+id/showProgress"android:text="click"android:layout_width="match_parent"android:layout_height="wrap_content"/></RelativeLayout>

packagecom.example.liang.at;importandroid.app.ProgressDialog;importandroid.support.v7.app.AppCompatActivity;importandroid.os.Bundle;importandroid.view.View;importandroid.widget.Button;publicclasspaextendsAppCompatActivity{@OverrideprotectedvoidonCreate(BundlesavedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.activity_pa);Buttonbt=(Button)findViewById(R.id.showProgress);bt.setOnClickListener(newView.OnClickListener(){@OverridepublicvoidonClick(Viewv){ProgressDialogprogressDialog=newProgressDialog(v.getContext());progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);progressDialog.setIcon(R.drawable.loading);progressDialog.setMessage("Loading...");progressDialog.setCancelable(false);progressDialog.show();}});}}