简单的画布操作

最新推荐文章于 2024-01-22 19:59:30 发布

原创最新推荐文章于 2024-01-22 19:59:30 发布 · 204 阅读

0 ·

CC 4.0 BY-SA版权

本文介绍了一个自定义Android视图类PointView，演示了如何使用Canvas和Paint类来绘制文本、路径等基本图形元素。文章通过具体实例展示了不同绘图方法的应用场景。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

public class PointView extends View{
    public PointView(Context context) {
        super(context);
    }

    public PointView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    public PointView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        Paint paint=new Paint();
        paint.setColor(Color.BLUE);
        //只有边框
        paint.setStyle(Paint.Style.STROKE);
        //锯齿
        paint.setAntiAlias(true);
        //边框宽度
        paint.setStrokeWidth(2);
        //一个点
        //canvas.drawPoint(200,200,paint);
        //多个点
        //float[] pts={100,100,200,200,300,300};
       // canvas.drawPoints(pts,paint);
        //一条线
        //canvas.drawLine(100,100,300,300,paint);
        //矩形
        // Rect rect=new Rect(100,100,500,500);
        //canvas.drawRect(rect,paint);
        //椭圆
        /*RectF rectf=new RectF(100,100,500,300);
        canvas.drawOval(rectf,paint);*/
        //圆弧
       /* RectF recf=new RectF(100,100,700,700);
        canvas.drawArc(recf,0,60,false,paint);*/
        String text = "我是祖国的花朵";
        paint.setTextSize(20);
        canvas.drawText(text,100,30,paint);
         Path path = new Path();
        //Path.Direction.CCW逆时针...CW顺时针
        path.addCircle(300,300,200, Path.Direction.CW);
        canvas.drawTextOnPath(text,path,0,0,paint);
    }
}