#1.下载utils项目

https://github.com/wyouflf/xUtils

#2布局文件里实现UI

<LinearLayout xmlns: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:orientation="vertical"

    tools:context=".MainActivity" >

    <EditText

        android:id="@+id/tv_path"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:text="http://down.360safe.com/inst.exe" />

    <Button

        android:layout_marginTop="10dip"

        android:layout_width="match_parent"

        android:onClick="download"

        android:layout_height="wrap_content"

        android:text="下载"

         />

    <TextView

         android:id="@+id/tv_info"

          android:layout_width="match_parent"

          android:layout_marginTop="10dip"

      	  android:layout_height="wrap_content"

      	  android:text="提示信息"

         />

</LinearLayout>

#3.在mainactivity中实现代码功能

package com.wzw.downloaddemo;

import java.io.File;

import com.lidroid.xutils.HttpUtils;

import com.lidroid.xutils.exception.HttpException;

import com.lidroid.xutils.http.HttpHandler;

import com.lidroid.xutils.http.ResponseInfo;

import com.lidroid.xutils.http.callback.RequestCallBack;

import android.os.Bundle;

import android.app.Activity;

import android.view.Menu;

import android.view.View;

import android.widget.EditText;

import android.widget.TextView;

public class MainActivity extends Activity {

	private EditText etPath;

	private TextView tvInfo;

	@Override

	protected void onCreate(Bundle savedInstanceState) {

		super.onCreate(savedInstanceState);

		setContentView(R.layout.activity_main);

		etPath=(EditText) findViewById(R.id.tv_path);

		tvInfo=(TextView) findViewById(R.id.tv_info);

	}

	public void download(View v){

		String path =etPath.getText().toString();

		HttpUtils http = new HttpUtils();

		http.download(path, "/sdcard/360.exe", true, true, new RequestCallBack<File>() {

	<span style="white-space:pre">	</span>@Override

	        public void onStart() {

	            tvInfo.setText("正在连接...");

	        }

			 @Override

		    public void onLoading(long total, long current, boolean isUploading) {

		           tvInfo.setText(current + "/" + total);

			 }

			 @Override

		     public void onFailure(HttpException error, String msg) {

		           tvInfo.setText(msg);

		      }

			@Override

			public void onSuccess(ResponseInfo<File> responseInfo) {

				// TODO Auto-generated method stub

				tvInfo.setText("downloaded:" + responseInfo.result.getPath());

			}

		});

	}

}

用Utils的话比用传统的方式要方便的多。