（十五）APK的安装、卸载、分享、运行的代码

/**
         * 安装apk
         * 
         * @param file 要安装的APK文件
         */
        private void install(File file) {

            Intent intent = new Intent();
            intent.setAction(Intent.ACTION_VIEW);
            intent.setDataAndType(Uri.fromFile(file),
                    "application/vnd.android.package-archive");
            finish();
            startActivity(intent);
        }

Intent shareIntent = new Intent();
            shareIntent.setAction(Intent.ACTION_SEND);
            shareIntent.setType("text/plain");
            // 需要指定意图的数据类型
            shareIntent.putExtra(Intent.EXTRA_SUBJECT, "分享");
            shareIntent.putExtra(Intent.EXTRA_TEXT,
                    "推荐你使用一个程序" + item.getAppname());
            shareIntent = Intent.createChooser(shareIntent, "分享");
            startActivity(shareIntent);

String uristr = "package:" + packname;
                Uri uri = Uri.parse(uristr);
                Intent deleteIntent = new Intent();
                deleteIntent.setAction(Intent.ACTION_DELETE);
                deleteIntent.setData(uri);
                startActivityForResult(deleteIntent, 0);

try {
                PackageInfo info = getPackageManager().getPackageInfo(
                        packname,
                        PackageManager.GET_UNINSTALLED_PACKAGES
                                | PackageManager.GET_ACTIVITIES);
                ActivityInfo[] activityinfos = info.activities;
                if (activityinfos.length > 0) {
                    ActivityInfo startActivity = activityinfos[0];
                    Intent intent = new Intent();
                    intent.setClassName(packname, startActivity.name);
                    startActivity(intent);
                } else {
                    Toast.makeText(this, "当前应用程序无法启动", 0).show();
                }
            } catch (Exception e) {
                Toast.makeText(this, "应用程序无法启动", 0).show();
                e.printStackTrace();
            }