ActionBarSherlock design

ActionBarSherlock is a framework for Android to implement an ActionBar before Android version 3.0, where there is a native ActionBar.

Example of action bar with its own design under Android 2.3.3

In addition, you can use many functions,even the native ActionBar makes not possible, You can get the best an overview through the installation of the Sample App on an Android device.

One difficulty of the framework is in the individualization of design, This is possible without the very difficult Online style generator for ActionBarSherlock. With this amount of time can be save, absolutely to recommend!

Enabled search box in action bar


Comparison of Augmented Reality Framework for Android

project nameMixingDroidARAndARvuforiawiktitudeandroid-augment-reality-framework
total ratingBCDA-BF
project urlMixingDroidARAndARvuforiawiktitudeandroid-augment-reality-framework
licenceGNU GPL v3GNU GPL v3GNU GPL v3Anonymous Data collection by Qualcomm,
Attribution License, the logo must be shown ether in loading, splash or credit screen license
not free, 599€ per App PricingApache License 2.0
version0.9.2??1.5.9.?initial version
latest build22.08.2012??22.02.2012?01.12.2011
tested Devices/Android Versionokno informationgoodvery good?
tested Devices URLLinkLinkAndroid 2.2 and newer, iOS 4 & 5.?
getting startedLinkLinkLinkLink?
Sample VideoLink
sample appLinkLinkLinkLink and Link
special featuresespecially for 3D Objects (with commercial licence)for ios and androidruns in webview (like phonegap), easy implementation for android, ios etc but performance issues may occur, very good customizable
conclusionactive community and steady buildsfew documentation and no information about tested devicesprojects is not maintained any morevery good documentation and device support, critical licence and complex intital setupnot free and few informations on the website, might have performance issues but easy to implement with HTML5project is not maintained any more


I chose Mixing decided, which gecodet well, but less well documented is. Is it very easy to own data or Wikipedia to put data on the camera and simultaneously view the same data as on Google Maps markers.

Vuforia to appear for the development of Android / iPhone solutions of suitable Kanditat be, However, when required under the license, that user data to the Qualcomm server are sent and the user must be informed:

Excerpt from the license of Vuforia

“You must inform end-users of your application that certain types of anonymous usage data is collected by the Vuforia SDK and sent back to Qualcomm servers.”

“(i) the collection by QUALCOMM and/or its affiliates of Statistics from the Software (including but not limited to: (a) information about the end users’ Such devices have device unique identifier, make, model, operating system name and version and kernel version, (b) information about our Software used to create your software or augmented reality end user application such as the SDK version and device profile, and (c) information about your software or augmented reality application and its use such as settings (e.g., camera resolution settings, configuration settings), start and stop dates and times, camera on/off events, target image obtained/lost events, and other general usage information (collectively “Statistics”)).”

Android automatic error reports from users with ACRA

A handy library for Android apps is Acra (Application Crash Report for Android), so can register to an error on the phone of a user sending the message as:

  • Google Docs spreadsheet (default)
  • Email
  • own HTTP POST Server Script
  • any other possible processing by implementing your own “report senders”

In case of a Crahs can meet the user in the following ways with the error:

  • Silent (default): ACRA actions are not visible. The crash report is sent and then the default android crash system does its job (Force Close dialog)
  • Toast: When the crash occurs, ACRA displays a toast and simultaneously sends the report.
  • Notification: An optional toast is displayed on application crash, but the report is not sent immediately. A status bar notification is published warning the user that he should send a report. When selected, the notification displays a dialog asking for the authorization to send the report, with an optional user comment.
  • Dialogue: since 4.3.0b1, experimental, allows to display a crash dialog without the need of a status bar notification.

Installation more…

Amazon S3 Android SDK Error: RequestTimeTooSkewed

If an error message:

Status Code 403, AWS Request ID:.... RequestTimeTooSkewed The difference between the request time and the current time is too large. 

Manually place it helps the clock on the phone, Amazon otherwise because of a too old request originates and blocks, when the time differs by more than 15minutes from the Amazon Time.

Unfortunately there is no other solution to support Amazon page: siehe Thread.

Android Failed to fetch URL, reason: Connection to refused

When the error message Failed to fetch URL, reason: Connection to refused has helped me following:

Test the XML Web

when the page is displayed in the browser without problems (it is because text, no error message), you have to take the following steps:

Configure the firewall

  • Disable Firewall, or. Except for SDK Manager.exe add (that was it for me)

Force enable https

  • start the sdk manager (not from Eclipse!): C:\Program Files (x86)\Android\android-sdk\SDK Manager.exe
  • Tools/Options
  • check: force https:// ….

Installing SDK packages

Thus, the SDK files are installed correctly, must SDK Manager.exe be started as administrator: Right-click on the file and Run as administrator.

Android App in the Google Play Market set Windows7

If one wants to put his hard ercodete app in the Google Play Market has to perform a few simple steps. In comparison to the recording process in the Apple App Store, these mainly involve little effort.

  1. Creating a Developer Accounts for Play Market. There must be a one-time fee of 25$ be paid, however, necessarily with a Google Checkout account, the one with a credit card (e.g.: Visa) must connect.
  2. The apk must be provided with a valid certificate, otherwise it returns an error message: 
Google Play akzeptiert keine mit dem Debug-Zertifikat signierten APK-Dateien. Erstellen Sie ein neues Zertifikat, das mindestens 50 Jahre gültig ist.

Certify the App with a valid certificate


Part 2: Clean Code – correct and incorrect comments

According to the book (Chapter 4):  “Clean Code – Refactoring, Patterns, Testing and techniques for clean code” of Robert C. Martin.

“Comment not bad code – write to him.”

(Brian W. Kernighan und P.J. Plaugher)


Comments can be both, helpful and hindering:

  • hindrance, if you are outdated and incorrect information supply
  • disturbing, if you are too long and unnecessarily
  • helpful, if you are well placed

The use of comments “our inability to balancing, clear to us in our code to express”(S.85). Before writing a comment, one should consider before, whether the code can not be further written expressive.


Huawei Ideos X3 USB Debugging Tutorial

The Huawei Ideos X3 (U8510 Blaze) is the very affordable entry level Android phone for programmers and students (< 100€).

Always begin with the USB driver will be installed. These are stored on the phone. A very good guide can be found here. Alternatively, you can also easily download the driver and install: Download.

To activate the USB debugging when Huwaei Ideos X3, must be chosen following number to get into the hidden menu:


20120430-220205.jpgThen the Project Menu>3. Background setting->2. Log setting

->Log level setting, verbose select.

->Log switch, Log on select

Then the Project Menu>3. Background setting->6. Dump & Log Select

  • Open Dump & Log
  • Changing log switch
  • Open Sleep Log

Your Huawei Ideos X3 is ready debugging information and detailed error messages to their IDE (Eclipse) to send.

To Testing for high-end Android devices: Read: Samsung S2 Galayx Debugging.

Mobile developers Recommendation: Samsung Galaxy Nexus mit Android 4.0

Developers Tablet Recommendation:&nbsp;Samsung Galaxy tab 2 mit Android 4.0

Part 1: Clean Code – Rules for good, clean code

To write clean code and easy to understand the ultimate goal is a good IT Projet. Much depends on:

  • Maintainability
  • Training time for other programmers, means fast, what do individual functions
  • Robustness to changes
  • Testability, everything falls together, with small changes, can quickly stable updates are
  • Popularity with other programmers e.g.: bei Open Source Projekten, as a negative example is called XT-Commerce

The highly recommended standard work on the subject is “Clean Code – Refactoring, Patterns, Testing and techniques for clean code” of Robert C. Martin. In this article, chapter 1 to 3 treated.

Meaningful names

The name of a variable, Function or class should declare immediately, why you exist, what it does and how it is used. If a variable requires a Comment, It expresses not its purpose.


int d //Anzahl vergangener Tage
besser ist:
int daysSinceCreation;

Pronounceable name use

No constructs with unclear abbreviations as: int daSiCre instead of daysSinceCreation.

Searchable name use

Modern IDEs make searching easy, but it's no, when you have to look for the letters e and a control variable is swamped by results.

Variable names with a letter must only be used as local variables in short methods.