Skip to main content

Use of List String blocks in Sketchware android projects.

A string list is an ordered collection of strings, where user has precise control over where in list each string is added. Use of list blocks in Sketchware projects is described below.

Adding elements to list

Elements can be add to a list one by one, and they take the position as per the sequence in which they are added.
For example, if we add Google, Yahoo, Amazon, YouTube, and Android to a list, they will take positions 0, 1, 2, 3, and 4 respectively.
If a very large number of elements are to be added to the list, as in some kind of word game, then multiple more blocks can be used to add elements to the list, and the more blocks can be used in a sequence in the event where list is to be created.
The images below show an example.



An important aspect of lists is that they allow duplicate elements and they allow multiple null elements.

Using List elements in Spinner or ListView

Elements added to a list can be shown in Spinner or ListView by setting their data to the list, as shown in the images below.
  a. Use of list in ListView

  b. Use of list in Spinner


Use of individual list blocks

1. Add...to List String...
This block is used to add elements to a list, as described above.

2. Inset...at...to List String...
This block can be used to insert an element at a particular position in between a list. If an element is inserted at position 3, the previous element at position 3 will shift to position 4, and all other elements at later positions will shift to one higher position.
The blocks used in the image above will give following result.
3. Delete at...of List...
This block can be used to delete an element from a particular position in list. All elements at higher positions will then shift down by one position.

4. Get at...of List String...
This block gets an element from a particular position in list.

5. Index...in list string...
This block gets the position of an element. For example, if Yahoo is at position 1, index Yahoo in List String will return result 1.

6. List String... contains...
This block checks if a particular string is there in the list.

7. Length of List...
This block gets the number of elements in the List. It counts from 1 to the last element. Thus, length of list is one higher than the last position in list.

8. Clear List...
This block deletes elements from all positions of the list.

Comments

Popular posts from this blog

Create Music Player app in Sketchware

To create a Music Player app in sketchware, follow the steps given below. 1. Create a new project in Sketchware. 2. In VIEW area on main.xml, add a ListView  listview1  with height wrap_content, and weight 1. Add a SeekBar  seekbar1 , an ImageView  imageview1 , and three TextViews  textview1 ,  textview2 , and  textview3 , as shown in the image below. 3. Create a CustomView  mycustom.xml  and add a TextView  textview1 , and an ImageView  imageview1  in it. For listview1 select mycustom.xml as it's customView. 4. Add a MediaPlayer component  mp , a Shared Preferences component  sp:sp  and a Timer component  timer . 5. Create six More Blocks  MPcreate(pos), MPstart , and  MPpause  for the MediaPlayer and  searchFolders ,  getFileList in [filePath]  and  extra . 6. Add three number variables  n, r  and  songPosition , and five String variables  currentfile ...

Admob rewarded video Ads in Sketchware

To integrate Admob Rewarded Video Ads to a Sketchware project, follow the steps given below. Prerequisites An Android project (Sketchware project) Account in Admob Always place the test ad unit ID before placing your ad unit ID. App ID and ad unit ID can be obtained by registering the app on Admob. But for using test ads no registration is required. Do not click on your own Ads. 1. Create an android project in Sketchware. 2. Add the app to your Admob account. For your app, generate an ad unit ID for Rewarded Video Ads. 3. In Sketchware project, navigate to  Library Manager  and open Admob settings. i. Click on Add manually and add the ad unit ID generated on Admob website, or use test ad unit ID ca-app-pub-3940256099942544/5224354917. ii. If you are not using any banner or interstitial ad units, select the same ad unit ID for both banner and interstitial ads. iii. Add Test Device automatically shown by Sketchware. iv. Save it. v. Switch ON Admob and AppCompat and design. ...

Firebase auth in Sketchware for Login Activity

To create a login activity using Firebase Auth in Sketchware, follow the steps given below. This method uses Firebase authentication service for creating login. 1. In your Firebase account, go to Firebase authentication. 2. In Firebase authentication web set-up, go to SIGN-IN method, and enable Email/password and Anonymous. 3. Go to Project settings in your Firebase project and copy the Web API Key, Project ID, and App ID. 4. Paste the Project ID, App ID, and Web API Key in your project in Sketchware, in the Firebase settings. 5. On the  MainActivity  page add a File Shared preferences component  user:user  and an Intent  i . Also add a Timer  t  and a Firebase Auth  testlogin . 6. Create a new page  login.xml  with Activity called  LoginActivity . 7. In  onCreate  event of MainActivity use blocks as shown in image below. It identifies main page with  File user key page . It also checks if user is logged in to  F...