一、通过Intent消息机制发送消息，调用系统应用进行，实现apk的安装/卸载 。 
（1） 调用系统的安装应用，让系统自动进行apk的安装 

String fileName = "/data/data/com.zlc.ipanel.operate/FileOperate.apk";
  Uri uri = Uri.fromFile(new File(fileName));
  Intent intent = new Intent(Intent.ACTION_VIEW);
  intent.setDataAndType(uri, "application/vnd.android.package-archive");
  startActivity(intent);

    上诉安装不仅可以安装新的apk（从无到有），也可以用于更新旧的apk（版本更新），在进行版本更新的时候，必须保证两个apk的签名是一致的。 
    如果是一般应用，安装到data/分区下面，新的apk会替换旧的apk。 
    如果是系统应用，一般安装到system/app下面，更新之后， system/app/下的旧apk仍然存在，系统会将新的apk被复制到data/app下。虽然同时存在两新旧apk，但运行时系统选择data分区的新apk运行， 如果执行卸载则是删除data分区的apk，再次启动程序运行的是system目录下旧的apk。 
（2）启动系统的卸载应用，让系统自动卸载apk 

//通过程序的包名创建URI
Uri packageURI = Uri.parse("package:com.zlc.ipanel");
//创建Intent意图
Intent intent = new Intent(Intent.ACTION_DELETE,packageURI);
//执行卸载程序
startActivity(intent);

与apk安装不同的是，Intent消息这里改了：ACTION_DELETE，apk安装使用的是（ACTION_VIEW）

二、通过调用系统提供的接口packageManager对apk进行卸载、安装、获取权限等（静默安装）
（1）需要平台签名（写个Android.mk在源码下编译最省事，当然网上也有很多其他方法，比如：singapk命令行签名）
（2）由于调用的是未公开的API，所以需要引入源码（仅仅做一个马甲，不参与编译）
（3）在AndroidManifest.xml添加安装apk的权限
    <uses-permission android:name="android.permission.INSTALL_PACKAGES" />
（4） 如果升级失败出现 Unable to open zip ‘/data/FileOperate.apk‘: Permission denied，说明是权限不够，有可能当前apk只有（-rw-------）权限，通过Runtime.exec方法修改权限之后再进行升级是可以成功 的。

PackageManager pm = this.getPackageManager();
  File file = new File("/data/data/com.zlc.ipanel.operate/FileOperate.apk");
  pm.installPackage(Uri.fromFile(file), null,
    PackageManager.INSTALL_REPLACE_EXISTING, "com.zlc.ipanel");

（5）下面举一个例子通过Eclipse来实现静默安装/卸载。
    1）按照我们上面讲的静默安装需求一步步实现我们的操作。首先准备马甲（静默安装需要调用的接口）
    由于调用了系统未公开的接口，而这些接口有些是通过aidl实现的，下面我们把需要的马甲修改一下。
    PackageManager.java

/*
* Copyright (C) 2006 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 android.content.pm;

import android.content.Context;
import android.net.Uri;

/**
* Class for retrieving various kinds of information related to the application
* packages that are currently installed on the device.
*
* You can find this class through {@link Context#getPackageManager}.
*/
public abstract class PackageManager {

    /**
     * Flag parameter for {@link #installPackage} to indicate that you want to replace an already
     * installed package, if one exists.
     * @hide
     */
    public static final int INSTALL_REPLACE_EXISTING = 0x00000002;

    /**
     * @hide
     *
     * Install a package. Since this may take a little while, the result will
     * be posted back to the given observer.  An installation will fail if the calling context
     * lacks the {@link android.Manifest.permission#INSTALL_PACKAGES} permission, if the
     * package named in the package file‘s manifest is already installed, or if there‘s no space
     * available on the device.
     *
     * @param packageURI The location of the package file to install.  This can be a ‘file:‘ or a
     * ‘content:‘ URI.
     * @param observer An observer callback to get notified when the package installation is
     * complete. {@link IPackageInstallObserver#packageInstalled(String, int)} will be
     * called when that happens.  observer may be null to indicate that no callback is desired.
     * @param flags - possible values: {@link #INSTALL_FORWARD_LOCK},
     * {@link #INSTALL_REPLACE_EXISTING}, {@link #INSTALL_ALLOW_TEST}.
     * @param installerPackageName Optional package name of the application that is performing the
     * installation. This identifies which market the package came from.
     */
    public abstract void installPackage(
            Uri packageURI, IPackageInstallObserver observer, int flags,
            String installerPackageName);

    /**
     * Attempts to delete a package.  Since this may take a little while, the result will
     * be posted back to the given observer.  A deletion will fail if the calling context
     * lacks the {@link android.Manifest.permission#DELETE_PACKAGES} permission, if the
     * named package cannot be found, or if the named package is a "system package".
     * (TODO: include pointer to documentation on "system packages")
     *
     * @param packageName The name of the package to delete
     * @param observer An observer callback to get notified when the package deletion is
     * complete. {@link android.content.pm.IPackageDeleteObserver#packageDeleted(boolean)} will be
     * called when that happens.  observer may be null to indicate that no callback is desired.
     * @param flags - possible values: {@link #DONT_DELETE_DATA}
     *
     * @hide
     */
    public abstract void deletePackage(
            String packageName, IPackageDeleteObserver observer, int flags);

}

安装成功的回调接口IPackageInstallObserver.java（修改过的马甲）

package android.content.pm;

import android.os.RemoteException;

public interface IPackageInstallObserver {
public class Stub implements IPackageInstallObserver{
  public void packageInstalled(String packageName, int returnCode)
    throws RemoteException {
   // TODO Auto-generated method stub

  }
}
}

卸载成功的回调接口IPackageDeleteObserver.java（修改过的马甲）

package android.content.pm;

public interface IPackageDeleteObserver {
public class Stub implements IPackageDeleteObserver{
  public void packageDeleted(String packageName, int returnCode) {
   // TODO Auto-generated method stub 
  }
}
}

    2）马甲准备好之后，就开始实现我们的操作逻辑。
    实现静默安装/卸载的方法，并且注册回调（无论失败成功都会返回对应值）   

 //静默安装
public static void installApkDefaul(Context context,String fileName,String pakcageName){
  Log.d(TAG, "jing mo an zhuang");
  File file = new File(fileName);
  int installFlags = 0;
  if(!file.exists())
   return;
  Log.d(TAG, "jing mo an zhuang  out");
  installFlags |= PackageManager.INSTALL_REPLACE_EXISTING; 
  PackageManager pm = context.getPackageManager();
  IPackageInstallObserver observer = new MyPakcageInstallObserver();
  pm.installPackage(Uri.fromFile(file), observer, installFlags, pakcageName);
}
//静默卸载
public static void uninstallApkDefaul(Context context,String packageName){
  PackageManager pm = context.getPackageManager();
  IPackageDeleteObserver observer = new MyPackageDeleteObserver();
        pm.deletePackage(packageName, observer, 0);
}
//静默卸载回调
private static class MyPackageDeleteObserver extends IPackageDeleteObserver.Stub{
  @Override
  public void packageDeleted(String packageName, int returnCode) {
   // TODO Auto-generated method stub
   Log.d(TAG, "returnCode = "+returnCode);//返回1代表卸载成功
  }

 }
//静默安装回调
private static class MyPakcageInstallObserver extends IPackageInstallObserver.Stub{
  @Override
  public void packageInstalled(String packageName, int returnCode)
    throws RemoteException {
   // TODO Auto-generated method stub
       Log.i(TAG, "returnCode = " + returnCode);//返回1代表安装成功 
  }
}

    3）主要的逻辑实现之后，在AndroidManifest.xml 添加安装和卸载的权限

<uses-permission android:name="android.permission.INSTALL_PACKAGES" />
<uses-permission android:name="android.permission.DELETE_PACKAGES" />

    4）运行Eclipse，生成该应用的apk，下面就要进行系统签名了。写一个脚本来来实现替换成系统签名
    使用签名包签名首先我们要去源码里面取出下面这几个文件platform.x509.pem、platform.pk8、signapk.jar
    
    脚本1.bat （和生成的apk以及上面三个文件放到同一个目录下面，一般为工程下面的bin目录）

java -jar  signapk.jar  platform.x509.pem  platform.pk8 FileUpdateControl.apk 1.apk
adb uninstall com.zlc.ipanel.operate
adb  install 1.apk

    5）当下载到系统里面的apk权限不够时（静默安装提示权限问题，有可能当前apk只有（-rw-------）权限）
    可以使用下面三种方式修改权限

    1.使用Runtime来启动一个线程修改权限

try {
   Runtime.getRuntime().exec("chmod 777 " + file.getCanonicalPath());
  } catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }

    2.写一个native接口直接通过jni调用c的接口修改权限。
    3.使用FileUtils，这个类默认是隐藏的，官方sdk中不包含这个类，所以代码如果要使用这个类，需要将工程放到android源码中编译
          FileUtils.setPermissions(f.getAbsolutePath(), FileUtils.S_IRUSR | FileUtils.S_IWUSR | FileUtils.S_IRGRP | FileUtils.S_IROTH, -1, -1) ;

三、其他apk安装的方法

    （1）通过cmd窗口 adb 命令，install / uninstall apk。
    （2）cp apk 到 system/app目录下，系统会自动安装 
    （3）直接通过代码调用pm命令执行apk的安装和卸载