Android Development for Beginners 19

Android Development for Beginners 19In this part of my App Inventor tutorial I will answer a bunch of questions. I’ll cover how to plan an application so that you can cut down on errors and have no problem with the blocks.

I will also show how to make a Android contacts app that store lists of people. You’ll also store that information in a TinyWebDB. We will then be able to update lists of lists on other screens. All the blocks are after the video below.

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First Use Case Descriptions

Write a Description : Update List Picker

  • When the user clicks Add Contact
    • Do we have a contact to add?
    • If so, create a list that will contain the contacts info
    • Add the contact list of data to the master list
    • Update the list picker
  • When the List Picker is updated
    • Create empty string that contains the picker elements
    • Make sure the master list has contacts in it
    • Add each contacts name to the list pickers element list
    • Add the element list to the list picker

First App Inventor Contact App Blocks

Click the image below to enlarge it

Contact App Blocks 1

Second Use Case Descriptions

Write a Description : Save Data to TinyWebDB

  • Catch any web service errors
  • Get data from the web service when the app loads
  • When data is received if it is a list and it has the correct tag store the data and update the list picker
  • If the data should be updated check that it is a list and then store it in the TinyWebDB

Second App Inventor Contact App Blocks

Click the image below to enlarge it

Contact App Blocks 2

6 Responses to “Android Development for Beginners 19”

  1. Chad W. says:

    Hey derek, im planning to develop an ios social network like instagram, fb, twitter and so on. But I only know objc and cocoa porgramming. What do i need to learn to be able to do so ( I actually dont know anything about backend programming) ? Is it php and sql? Do you know how good service is?
    Thank you, love your tutorials(my favorite ones are the java android programming).

    • Derek Banas says:

      Hey Chad,

      That is a major undertaking mainly because of security. It is very hard to secure a network if people are allowed to upload to it. I cover numerous ways people break into sites in my PHP security videos.

      If I was asked to do it, I’d probably use the Zend framework which is PHP. Yes you will need to understand SQL as well. I’d try to make another site first before taking on something that big.

  2. Achraf says:

    Hollow Derek I have a problem with Android SDK Manager , I do not can Install package for this Error “Failed to create directory C:\Program Files (x86)\adt-bundle-windows-x86_64-20140321\sdk\temp” Screen Shot here

    Please help me .
    Thank you.

  3. Nathan says:

    Hey Derek!

    I am learning to code using AppInventor as part of Project Lead The Way’s Computer Science and Software Engineering high school curriculum. Your videos have been an awesome resource.

    Any chance you could send me the sequence diagram you show during the beginning of this video?

    I know you mention that it complicates the process, but I am planning on building out a more complicated app with a team, and perhaps that would be a useful exercise for us. It would be cool to have a model!

    I left my email above, and would love to chat a little bit with you about what we’re trying to accomplish and how we could best go about it.

    Thanks for all your videos!!


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