下载app后自动安装程序

其实很简单，只需要几行代码就好了，首先要到服务器下载apk，然后才能安装，当然不是傻子应该都知道，我这里用到的是Httputils去下载，

这里需要一些权限

<uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
    <uses-permission android:name="android.permission.INSTALL_PACKAGES"/>

直接贴代码

package com.exmple.httpxutil;

import java.io.File;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Intent;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.content.pm.Signature;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ProgressBar;

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;

public class MainActivity extends Activity {
	HttpHandler<File> h;
	private ProgressBar pa;

	@SuppressLint("SdCardPath")
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		Button button = (Button) findViewById(R.id.button);
		pa = (ProgressBar) findViewById(R.id.pro);
		Button more = (Button) findViewById(R.id.more);
		getCode();
		more.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {
				Intent ints = new Intent(MainActivity.this, NewActivity.class);
				startActivity(ints);

			}
		});
		button.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {

				HttpUtils http = new HttpUtils();
				final String path = Environment.getExternalStorageDirectory()
						.getPath();
				System.out.println(path);

				h = http.download(
						"http://101.200.142.201:8080/tqyb/baidumap.apk", path
								+ "/badumap.apk", true, true,
						new RequestCallBack<File>() {
							@Override
							public void onStart() {
								System.out.println("===");
								System.out.println("开始下载了++++++++++++++");
							}

							@Override
							public void onLoading(long total, long current,
									boolean isUploading) {
								System.out.println(total + "=====");
								System.out.println(current + "=====");
								System.out.println(isUploading + "=====");
								pa.setMax((int) total);
								pa.setProgress((int) current);
							}

							@Override
							public void onFailure(HttpException error,
									String msg) {
								System.out.println(error + "+++++++" + msg
										+ "+++++++++");

							}

							@Override
							public void onSuccess(
									ResponseInfo<File> responseInfo) {
								h.cancel();
								installApk(path + "/badumap.apk");

							}

						});

			}
		});

	}
//安装的方法
	private void installApk(String filename) {
		File file = new File(filename);
		Intent intent = new Intent();
		intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
		intent.setAction(Intent.ACTION_VIEW);
		String type = "application/vnd.android.package-archive";
		intent.setDataAndType(Uri.fromFile(file), type);
		startActivity(intent);

	}
//等到版本号的代码
	private void getCode() {

		PackageManager manager;

		PackageInfo info = null;

		manager = this.getPackageManager();

		try {

			info = manager.getPackageInfo(this.getPackageName(), 0);
			String name = info.versionName;
			int versionCode = info.versionCode;
			String packageName = info.packageName;
			Signature[] signatures = info.signatures;
			System.out.println(name + "++++++++++" + versionCode + "+++++"
					+ packageName + "========nnn" + signatures
					+ "=============");
			/*
			 * info.versionName;
			 *
			 * info.packageName;
			 *
			 * info.signatures;
			 */

		} catch (NameNotFoundException e) {

			// TODO Auto-generated catch block

			e.printStackTrace();

		}

	}

}