android通过代码的形式来实现应用程序的方法

注意：
intent.setdataandtype(uri.fromfile(file), "application/vnd.android.package-archive");这一句话中,第一个参数是要安装的apk的路径,第二个参数是apk所对应的类型。可以砸tomcat的安装目录下的conf目录下的web.xml中找到
程序运行截图：

 代码实现如下：
1、main.xml

<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    <button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="安装"
        android:onclick="install"
        />
    <button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="卸载"
        android:onclick="uninstall"
        />
</linearlayout>

2、mainactivity

package com.njupt.install;
import java.io.file;
import android.net.uri;
import android.os.bundle;
import android.os.environment;
import android.app.activity;
import android.content.intent;
import android.view.menu;
import android.view.view;
public class mainactivity extends activity {
 @override
 protected void oncreate(bundle savedinstancestate) {
  super.oncreate(savedinstancestate);
  setcontentview(r.layout.main);
 }
 public void install(view v){
  intent intent = new intent();
  intent.setaction(intent.action_view);
  file file = new file(environment.getexternalstoragedirectory(),"htmlui1.apk");
  intent.setdataandtype(uri.fromfile(file), "application/vnd.android.package-archive");
  startactivity(intent);
 }
 public void uninstall(view v){
  intent intent = new intent();
     intent.setaction(intent.action_delete);
     intent.setdata(uri.parse("package:com.njupt.htmlui1"));
  startactivity(intent);
 }
 @override
 public boolean oncreateoptionsmenu(menu menu) {
  // inflate the menu; this adds items to the action bar if it is present.
  getmenuinflater().inflate(r.menu.main, menu);
  return true;
 }
}