<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:orientation="vertical"    android:gravity="center_horizontal">    <ImageView    android:layout_width="wrap_content"    android:layout_height="240dp"        android:src="@drawable/a" />    <Button        android:id="@+id/bn"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="确定" /></LinearLayout>

package com.example.dialogtheme;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;public class MainActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        Button bn=(Button) findViewById(R.id.bn);        bn.setOnClickListener(new OnClickListener(){            @Override            public void onClick(View v) {                //结束改Activity                finish();            }        });    }}