[Android]APK程序卸载二次确认的实现

严正声明

本人本着技术开放，思想分享的目的，撰写本文。文章仅供参考之用，请勿使之于非法或有害于社会和谐之用。

Sodino

2011-01-24

Android上能不能实现卸载时提示呢，比如卸载某某软件时，做个用户调查卸载的原因。 我以前想着是的不行的，以前的想法是： Windows上卸载时能实现此功能是因为有些程序的卸载是自己实现的，非系统操作。 但android上目前来说还不支持，系统卸载时，还没发现有啥接口可以和目标卸载程序交互。
呵呵，今天鼓捣LogCat,发现还是可以的。 实现基础是： 1.通过注册权限，能够获取LogCat的输出流的输出信息。 2.进入系统的卸载界面时，"打包安装程序(com.android.packageinstaller)"会输出如下信息
01-22 16:29:15.250: INFO/ActivityManager(147): Starting activity: Intent { act=android.intent.action.DELETE dat=package:lab.sodino.uninstallhint cmp=com.android.packageinstaller/.UninstallerActivity }
好了，有这句话就足够了。截取输出流信息，当获取字符串中包含"android.intent.action.DELETE"和"<you_package>"时，就启动卸载提示页面。
话就这么多了。接下来看效果图，上代码。

package lab.sodino.uninstallhint;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
/**
* @author Sodino E-mail:sodinoopen@hotmail.com
* @version Time：2011-1-12 上午10:09:59
*/
public class MainActivity extends Activity implements LogcatObserver {
private TextView txtInfo;
private Handler handler;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button btnScannerLogcat = (Button) findViewById(R.id.btnScanLogcat);
btnScannerLogcat.setOnClickListener(new Button.OnClickListener() {
public void onClick(View view) {
// 开启Logcat流监听
LogcatScanner.startScanLogcatInfo(MainActivity.this);
}
});
Button btnUninstallMe = (Button) findViewById(R.id.btnUninstallMe);
btnUninstallMe.setOnClickListener(new Button.OnClickListener() {
public void onClick(View view) {
// 调用应用程序信息
Intent intent = new Intent(Intent.ACTION_VIEW);
// com.android.settings/.InstalledAppDetails
intent.setClassName("com.android.settings", "com.android.settings.InstalledAppDetails");
intent.putExtra("pkg", "lab.sodino.uninstallhint");
startActivity(intent);
}
});
txtInfo = (TextView) findViewById(R.id.txtInfo);
handler = new Handler() {
public void handleMessage(Message msg) {
txtInfo.append(String.valueOf(msg.obj) + "/n");
}
};
}
public void handleNewLine(String info) {
Message msg = new Message();
msg.obj = info;
handler.sendMessage(msg);
if (info.contains("android.intent.action.DELETE") && info.contains(getPackageName())) {
// 启动删除提示
Intent intent = new Intent();
intent.setClass(this, UninstallWarningActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
}
}
}

package lab.sodino.uninstallhint;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
/**
*@author Sodino Email:sodinoopen@hotmail<br/>
*@version 2011-1-22 上午11:10:56
*/
public class LogcatScanner {
private static AndroidLogcatScanner scannerThead;
public final static void startScanLogcatInfo(LogcatObserver observer) {
if (scannerThead == null) {
scannerThead = new AndroidLogcatScanner(observer);
scannerThead.start();
LogOut.out(LogcatScanner.class, "scannerThread.start()");
}
}
static class AndroidLogcatScanner extends Thread {
private LogcatObserver observer;
public AndroidLogcatScanner(LogcatObserver observer) {
this.observer = observer;
}
public void run() {
String[] cmds = { "logcat", "-c" };
String shellCmd = "logcat";
Process process = null;
InputStream is = null;
DataInputStream dis = null;
String line = "";
Runtime runtime = Runtime.getRuntime();
try {
observer.handleNewLine(line);
int waitValue;
waitValue = runtime.exec(cmds).waitFor();
observer.handleNewLine("waitValue=" + waitValue + "/n Has do Clear logcat cache.");
process = runtime.exec(shellCmd);
is = process.getInputStream();
dis = new DataInputStream(is);
while ((line = dis.readLine()) != null) {
observer.handleNewLine(line);
}
} catch (InterruptedException e) {
e.printStackTrace();
} catch (IOException ie) {
ie.printStackTrace();
} finally {
try {
if (dis != null) {
dis.close();
}
if (is != null) {
is.close();
}
if (process != null) {
process.destroy();
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
}

package lab.sodino.uninstallhint;
/**
* @author Sodino E-mail:sodinoopen@hotmail.com
* @version Time：2011-1-22 下午03:00:54
*/
public interface LogcatObserver {
public void handleNewLine(String line);
}

package lab.sodino.uninstallhint;
import android.app.Activity;
import android.app.ActivityManager;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
/**
* @author Sodino E-mail:sodinoopen@hotmail.com
* @version Time：2011-1-12 上午10:26:09
*/
public class UninstallWarningActivity extends Activity {
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.uninstall_warning);
Button btnContinue = (Button) findViewById(R.id.btnContinue);
btnContinue.setOnClickListener(new Button.OnClickListener() {
public void onClick(View view) {
UninstallWarningActivity.this.finish();
}
});
Button btnCancel = (Button) findViewById(R.id.btnCancel);
btnCancel.setOnClickListener(new Button.OnClickListener() {
public void onClick(View view) {
UninstallWarningActivity.this.finish();
ActivityManager actMag = (ActivityManager) UninstallWarningActivity.this
.getSystemService(Context.ACTIVITY_SERVICE);
//杀掉系统的打包安装程序。
if (android.os.Build.VERSION.SDK_INT < 8) {
actMag.restartPackage("com.android.packageinstaller");
} else {
actMag.killBackgroundProcesses("com.android.packageinstaller");
}
Intent i = new Intent(Intent.ACTION_MAIN);
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
i.addCategory(Intent.CATEGORY_HOME);
startActivity(i);
}
});
}
}

最后在AndroidManifest.xml中添加上权限。