//開啟外部app，新視窗開啟
private void doStartApplicationWithPackageName(String packagename) {
        // 通過包名獲取此APP詳細資訊，包括Activities、services、versioncode、name等等
PackageInfo packageinfo = null;
        try {
            packageinfo = getPackageManager().getPackageInfo(packagename, 0);
} catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
 
}
        if (packageinfo == null) {
            BDToast.showToast(getText(R.string.app_not_found).toString());
            return;
}

        Intent resolveIntent = getPackageManager().getLaunchIntentForPackage(packagename);// 這裡的packname就是從上面得到的目標apk的包名
startActivity(resolveIntent);// 啟動目標應用}

//開啟外部app，嵌入舊視窗中
 
private void doStartApplicationWithPackageName(String packagename) {
    // 通過包名獲取此APP詳細資訊，包括Activities、services、versioncode、name等等
PackageInfo packageinfo = null;
    try {
        packageinfo = getPackageManager().getPackageInfo(packagename, 0);
} catch (PackageManager.NameNotFoundException e) {
        e.printStackTrace();
 
}
    if (packageinfo == null) {
        BDToast.showToast(getText(R.string.app_not_found).toString());
        return;
}
    // 建立一個類別為CATEGORY_LAUNCHER的該包名的Intent
Intent resolveIntent = new Intent(Intent.ACTION_MAIN, null);
resolveIntent.addCategory(Intent.CATEGORY_LAUNCHER);
resolveIntent.setPackage(packageinfo.packageName);
// 通過getPackageManager()的queryIntentActivities方法遍歷
List<ResolveInfo> resolveinfoList = getPackageManager()
            .queryIntentActivities(resolveIntent, 0);
ResolveInfo resolveinfo = resolveinfoList.iterator().next();
    if (resolveinfo != null) {
        // packagename = 引數packname
String packageName = resolveinfo.activityInfo.packageName;
// 這個就是我們要找的該APP的LAUNCHER的Activity[組織形式：packagename.mainActivityname]
String className = resolveinfo.activityInfo.name;
// LAUNCHER Intent
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_LAUNCHER);
// 設定ComponentName引數1:packagename引數2:MainActivity路徑
ComponentName cn = new ComponentName(packageName, className);
intent.setComponent(cn);
startActivity(intent);
}
}