狂刷Android范例之4：用代码安装卸载app

说明

狂刷Android范例系列文章开张了。每篇学习一个Android范例，将一个范例单独生成一个可运行的app，并对重点源代码进行简要分析。然后提供打包好的源代码下载。

功能

这个范例用来展示如何在程序中使用Intent来安装和卸载一个apk文件到用户的手机上。
其主要使用了Intent的Action和Data属性来指明希望的操作和需要安装的apk文件路径，该apk是放在本app的asset目录中作为一个资源。

代码包在此，无需下载分：
http://download.csdn.net/detail/logicteamleader/8797651

来源

ReadAsset例子来自于Android-20的com.example.android.apis.content.InstallApk。
我进行了一点修改，主要是用上篇blog中产生的ClipboardSample.apk文件替换了原来的HelloActivity.apk，因为HelloActivity.apk在我的手机上因为版本问题不能安装。因此采用了与本程序相同版本的ClipboardSample.apk，确保本程序能够正常运行。

环境

代码运行环境：
1.ADT2014版本；
2.android:minSdkVersion=”14”；android:targetSdkVersion=”20”
3.workspace中已经生成了appcompatv7，它的版本是android-22；

代码

需要注意的类就是Intent，它的隐式调用方法。

/* * Copyright (C) 2011 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * *      http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package com.example.installapk;// Need the following import to get access to the app resources, since this// class is in a sub-package.import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import android.app.Activity;import android.content.Context;import android.content.Intent;import android.net.Uri;import android.os.Bundle;import android.util.Log;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.Toast;/** * Demonstrates using the INSTALL_PACKAGE Intent to install an application */public class InstallApk extends Activity {    static final int REQUEST_INSTALL = 1;    static final int REQUEST_UNINSTALL = 2;    static final String MY_APK_NAME ="ClipboardSample.apk";    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.install_apk);        // Watch for button clicks.        Button button = (Button)findViewById(R.id.unknown_source);        button.setOnClickListener(mUnknownSourceListener);        button = (Button)findViewById(R.id.my_source);        button.setOnClickListener(mMySourceListener);        button = (Button)findViewById(R.id.replace);        button.setOnClickListener(mReplaceListener);        button = (Button)findViewById(R.id.uninstall);        button.setOnClickListener(mUninstallListener);        button = (Button)findViewById(R.id.uninstall_result);        button.setOnClickListener(mUninstallResultListener);    }    /*      * 启动的Activity返回时的处理函数，主要是根据requestCode和resultCode进行install和uninstall成功     * 或者失败的信息展示     */    @Override    public void onActivityResult(int requestCode, int resultCode, Intent intent) {        if (requestCode == REQUEST_INSTALL) {            if (resultCode == Activity.RESULT_OK) {                Toast.makeText(this, "Install succeeded!", Toast.LENGTH_SHORT).show();            } else if (resultCode == Activity.RESULT_CANCELED) {                Toast.makeText(this, "Install canceled!", Toast.LENGTH_SHORT).show();            } else {                Toast.makeText(this, "Install Failed!", Toast.LENGTH_SHORT).show();            }        } else if (requestCode == REQUEST_UNINSTALL) {            if (resultCode == Activity.RESULT_OK) {                Toast.makeText(this, "Uninstall succeeded!", Toast.LENGTH_SHORT).show();            } else if (resultCode == Activity.RESULT_CANCELED) {                Toast.makeText(this, "Uninstall canceled!", Toast.LENGTH_SHORT).show();            } else {                Toast.makeText(this, "Uninstall Failed!", Toast.LENGTH_SHORT).show();            }        }    }    //通过设置Intent的Action为Intent.ACTION_INSTALL_PACKAGE    //来启动一个系统app进行apk文件的安装    //apk文件的uri在intent的data中设置    private OnClickListener mUnknownSourceListener = new OnClickListener() {        public void onClick(View v) {            Intent intent = new Intent(Intent.ACTION_INSTALL_PACKAGE);            intent.setData(Uri.fromFile(prepareApk(MY_APK_NAME)));            startActivity(intent);        }    };//    同上，区别是设置了一些参数，并且使用startActivityForResult启动intent，可得到返回结果    private OnClickListener mMySourceListener = new OnClickListener() {        public void onClick(View v) {            Intent intent = new Intent(Intent.ACTION_INSTALL_PACKAGE);            intent.setData(Uri.fromFile(prepareApk(MY_APK_NAME)));            intent.putExtra(Intent.EXTRA_NOT_UNKNOWN_SOURCE, true);            intent.putExtra(Intent.EXTRA_RETURN_RESULT, true);            intent.putExtra(Intent.EXTRA_INSTALLER_PACKAGE_NAME,                    getApplicationInfo().packageName);            startActivityForResult(intent, REQUEST_INSTALL);        }    };    //使用intent来替换一个apk，可得到返回结果    private OnClickListener mReplaceListener = new OnClickListener() {        public void onClick(View v) {            Intent intent = new Intent(Intent.ACTION_INSTALL_PACKAGE);            intent.setData(Uri.fromFile(prepareApk(MY_APK_NAME)));            intent.putExtra(Intent.EXTRA_NOT_UNKNOWN_SOURCE, true);            intent.putExtra(Intent.EXTRA_RETURN_RESULT, true);            intent.putExtra(Intent.EXTRA_ALLOW_REPLACE, true);            intent.putExtra(Intent.EXTRA_INSTALLER_PACKAGE_NAME,                    getApplicationInfo().packageName);            startActivityForResult(intent, REQUEST_INSTALL);        }    };    //使用intent来卸载一个app    private OnClickListener mUninstallListener = new OnClickListener() {        public void onClick(View v) {            Intent intent = new Intent(Intent.ACTION_UNINSTALL_PACKAGE);            intent.setData(Uri.parse(                    "package:com.example.clipboardsample"));            startActivity(intent);        }    };    //使用intent来卸载一个app，可得到返回结果    private OnClickListener mUninstallResultListener = new OnClickListener() {        public void onClick(View v) {            Intent intent = new Intent(Intent.ACTION_UNINSTALL_PACKAGE);            intent.setData(Uri.parse(                    "package:com.example.clipboardsample"));            intent.putExtra(Intent.EXTRA_RETURN_RESULT, true);            startActivityForResult(intent, REQUEST_UNINSTALL);        }    };    private File prepareApk(String assetName) {        // Copy the given asset out into a file so that it can be installed.        // Returns the path to the file.        byte[] buffer = new byte[8192];        InputStream is = null;        FileOutputStream fout = null;        try {            is = getAssets().open(assetName);            fout = openFileOutput("tmp.apk", Context.MODE_WORLD_READABLE);            int n;            while ((n=is.read(buffer)) >= 0) {                fout.write(buffer, 0, n);            }        } catch (IOException e) {            Log.i("InstallApk", "Failed transferring", e);        } finally {            try {                if (is != null) {                    is.close();                }            } catch (IOException e) {            }            try {                if (fout != null) {                    fout.close();                }            } catch (IOException e) {            }        }        return getFileStreamPath("tmp.apk");    }}