Android Studio Hello World

Start/All Program/Android Studio/Android Studio

I do not have a previous version … OK

Lack of permissions Android Studio likes to update often. You probably do not have the necessary permissions on the lab computers so avoid clicking on update.

Next. Maybe only the first user (me for the lab computers) sees this.

Next (again)

Finish

Finish (again)

Start a new Android Studio project

Name the application and click Next

Select a minimum SDK. Next.

Next

Choose an empty activity. Next

Finish

Close tip of the day

Click the Run App button (green arrow)

If there is a virtual device available choose it If there is a virtual device available choose it. If not, click on create New Virtual Device

Next

Select a system image

Agree to license. Next.

Finish

Select image. Next.

Finish

OK

Install and continue

Finish

After closing the emulator and running again

Go to activity_main.xml (see res/layout)

Right click on “Hello world” TextView and select Cut.

Click ON the Auto Connect (U) button

Drag a button from the palette to the layout

Change the button’s id and text

Drag from the little circle on top to the top of the container and from the circle of the right and left edge to the side of the container

Result in Text View. Constraints are important in the ConstraintLayout

Drag a TextView onto the Layout

Change the TextView’s id and text

Apply the constraints – this time connect the top of the TextView to the bottom of the Button

Result

Additional property it asked for to eliminate red

Return to MainActivity – begin to instantiate a button object

Put mouse over Button (which was red) and click Alt-Enter Put mouse over Button (which was red) and click Alt-Enter. Adds the import android.widget.Button

Start adding the button’s setOnClickListener method

Add required onClick method

Instantiate TextView object and use its setText method

Run Problem you may find: if you did not take care of the constraints, the TextView and Button may be on top of one another.