Android如何自定义dialog

package com.example.aqua.myapplicationtesthttp;

import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.text.Layout;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;

/**
 * Created by Aqua on 2015/12/15.
 */
public class PopUpView extends Dialog {

    public PopUpView(Context context) {
        super(context);
 }

    public PopUpView(Context context, int theme) {
        super(context, theme);
 }

    public static class Builder {
        private Context context;
        private String message;
        private String positiveButtonText;
        private DialogInterface.OnClickListener positiveButtonClickListener;

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

        public Builder setMessage(String message) {
            this.message = message;
            return this;
 }

        public Builder setPositiveButton(int positiveButtonText,
 DialogInterface.OnClickListener listener) {
            this.positiveButtonText = (String) context
 .getText(positiveButtonText);
            this.positiveButtonClickListener = listener;
            return this;
 }

        public Builder setPositiveButton(DialogInterface.OnClickListener listener) {
            this.positiveButtonClickListener = listener;
            return this;
 }

        public PopUpView create() {
            LayoutInflater inflater = (LayoutInflater) context
 .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

 // instantiate the dialog with the custom Theme
 final PopUpView dialog = new PopUpView(context);
 dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
 View layout = inflater.inflate(R.layout.popupview, null);
//            ViewGroup.LayoutParams pp = new ViewGroup.LayoutParams(500,300);//使用此处修改Dialog的宽和高
 ViewGroup.LayoutParams pp = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
 dialog.addContentView(layout, pp);
 dialog.setCancelable(false);//使dialog不会消失

 //修改Dialog的宽度和高度
 Window window = dialog.getWindow();
 WindowManager.LayoutParams lp = window.getAttributes();
 lp.alpha = 0.7f;
 lp.width = 500;
 lp.height = 300;
 window.setAttributes(lp);

 // set the confirm button
 if (positiveButtonClickListener != null) {
                ((Button) layout.findViewById(R.id.btn))
                        .setOnClickListener(new View.OnClickListener() {
                            public void onClick(View v) {
                                positiveButtonClickListener.onClick(dialog,
 DialogInterface.BUTTON_POSITIVE);
 }
                        });
 }

            // set the content message
 if (message != null) {
                ((TextView) layout.findViewById(R.id.msg)).setText(message);
 }

           // dialog.setContentView(layout);切忌不需要这一句
 return dialog;
 }

    }
}