Shuttle uses custompaint to paint basic shapes

Preface

Last one First time to know Flutter Drawing components for — CustomPaint We introduced CustomPaint The basic concept and use of , You can see CustomPaint Actually sum Front-end Canvas It's basically the same , Actually the front end Canvas Supported drawing methods CustomPaint All support , After all CustomPaint It's also based on Canvas Realized . In this article we will introduce CustomPaint Drawing basic graphics .

Draw a rectangle

Drawing a rectangle is relatively simple , The method is defined as follows ：

void drawRect(Rect rect, Paint paint)

among rect To draw a rectangle ,paint That is, the brush configuration object . For example, we want to draw a width horizontally in the middle 200 x 120 The rectangular , You can use the following code ：

canvas.drawColor(Color(0xFFF1F1F1), BlendMode.color);
var center = size / 2;
//  Draw a rectangle 
var paint = Paint()..color = Color(0xFF2080E5);
paint.strokeWidth = 2.0;
canvas.drawRect(
  Rect.fromLTWH(center.width - 100, 60, 200, 120),