Programming Tutorials

Android Kotlin - How to draw dotted line on a Canvas This code demonstrates how to draw a dotted line on a canvas in an Android app written in Kotlin. It utilizes an ImageView to display the line and a SeekBar to control the width of the dots. Explanation: MainActivity.kt: The onCreate method sets up the UI elements, including the ImageView and SeekBar . It calls the drawDottedLine function with the initial dot width (progress + 10) to create a bitmap with the dotted line. This bitmap is then set to the ImageView . A SeekBar.OnSeekBarChangeListener is implemented to update the dotted line whenever the user adjusts the seekbar. The listener retrieves the new progress value, generates a new bitmap with the updated dot width, and sets it back to the ImageView . drawDottedLine function: This function takes an optional dotWidth parameter (default 25f) and creates a new bitmap with a specified size and ARGB_8888 config (supports transparency). It creates a Canvas objec...