“100 Best App Inventor Tutorial Videos”

This is a machine generated list of App Inventor tutorial videos. I have no idea which ones are the best (some appear to be out of date, for AI version 1) but you might find these links of use:

Link updated March 24, 2017 – try this one:

100 Best AppInventor Tutorial Videos | Meta-Guide.com.

 

Total MIT App Inventor registered users reaches 2.7 million

The total number of MIT App Inventor registered users has reached 2.7 million.

My guess is the number went up, in part, due to the “Hour of Code” project in December, which provided young students with very brief introductions to many types of programming.

Using the Spinner Control for Selecting Items

When your app needs the user to select an item from a list of choices, use the Spinner control.

Suppose we have a really simple restaurant menu that provides a choice of tacos and drinks. Our customer may select a Chicken, Beef or Vegan taco from an interface that looks like this:

Spinner-Screen

Touching the Chicken Taco item on the screen displays a set of options – select a desired item from the list:

SpinnerScreenshotThe Designer View

Continue reading Using the Spinner Control for Selecting Items

Updated: Writing and Reading Text Files Using App Inventor

This post is a major update to a previous post on reading and writing text files using App Inventor. This revision includes information on how to locate the text files you create in your App Inventor apps, plus how to transfer those files from your smart phone or tablet to your computer.

An earlier blog post described how to store data using TinyDB so that an app’s data can persist between uses of the program, or even to share data between screens in a program.

Another way to save data is to write the data to a file on your Android device. App Inventor has introduced a File control that lets us write text data to a file and then read it back, later. As we will see, the File control is not the easiest thing to use but with some work, the control can be used to store data from our program into a file.

Once data is in a file, you could, hypothetically, transfer the file from an Android to device to another computer. Because Android stores the files in a way that they may not be readily accessible – or even visible – we need to use some simple tricks to find the file and transfer the file to a computer.

Update: To learn more about text files and transferring data in the CSV file format, check out Volume 3 of “App Inventor 2 Databases and Files” – thanks!

Continue reading Updated: Writing and Reading Text Files Using App Inventor

Update: Reading and writing text files with App Inventor

I previously posted a short tutorial on writing to and reading from text files stored on an Android device, using an App Inventor app.

Unfortunately, as some comments noted, the file being created seems to disappear – the data is written and can be read back – but the file is no where to be found on the phone!

After some research, I now know where the file is – and also how to copy the file from the phone (or tablet) to your personal computer.  While the solution to finding and saving the file to your computer is ultimately easy, I need to update the tutorial and explain some things about the Android file system. You will also need to install a free app on your phone in order to copy the file to your computer.

I have posted an updated tutorial that explains the details and shows how to store your files in the right location, how to find them (they are hidden from most views), and how to copy them to your personal computer.

App Inventor Alert: Problems loading projects?

From the MIT App Inventor web site:

Summary: We have been having problems with storing “assets” image, sounds and other objects that you upload to your projects. We are working with Google to resolve these problems as soon as possible.

Things to be aware of:

If we fail to read an asset when you load your project, we substitute a zero-length file. Be careful exporting your projects, as assets may be missing from the “.aia” file exported. Make sure you keep a local copy of your assets on your own computer.

We have been making modifications to the system to mitigate the worst of the problems. In particular we will never serve up a missing asset to the “buildserver” when you package an App. This ensure that if you successfully package an App, the resulting APK is valid. If we fail to read an asset, you will get a “Build Failed” message. If this happens, just keep trying the build. It may work the second or third time around. If it never seems to work, you can remove your assets from your project and upload them again. This may help.

via Problems loading projects?.

December 8-14 is Computer Science Education Week

The Computer Science Education Week coincides with the “Hour of Code” initiative. This example lesson is based on MIT’s Scratch (which is similar to App Inventor).

There are 33 introductory tutorials available for the “Hour of Code” project (teachers may optionally create their own as well).

One of the official tutorial opportunities is based on App Inventor.

Use caution in interpreting the hype over “Hour of Code”. It’s a primitive introduction to some limited programming concepts; many of the tutorials have limited association with computer science. If your expectations are set appropriately, its fine.

Google expected to introduce new Java compiler

The upcoming Jack & Jill compilers in Android | Saikoa.

Most Android apps are written in the Java programming language. Google’s Android software development system converts “source code” (a text file) written in Java, into the code that runs on the Android device.

In many programming language systems, source code is converted into the “machine instructions” of the processor. The processor does not speak “Java” but speaks its own language. A program called a “compiler” converts the original program source code into the “machine language” of the processor.

Many programs for Windows, for example, have been converted into the individual instructions that are processed by an Intel or AMD processor. The “compiler” converts the program source code into a .exe file that contains the machine language instructions of the Intel and AMD processor.

But what if you wanted your program to run on a hardware device that has a Qualcomm or ARM processor?

Continue reading Google expected to introduce new Java compiler

The quick and easy way to write Android Apps