狂刷Android范例之4：用代码安装卸载app

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");
    }
}