如何在画布上动画路径 - android [英] How to animate a path on canvas - android

问题描述

是否可以将动画师附加到路径上?有没有其他方法可以在画布上绘制动画线条?我在发帖之前搜索了这个，但没有关于这个.在另外两篇文章这里和这里 有四处走动的解决方案，不适合我.

Is possible to attach an animator to a path? Is there any other way to draw on canvas animated lines? I searched this before i post , but there is nothing about this. In two other posts here and here there are walk around solutions and does not fit to me.

我在 onDraw 方法中发布了我的代码来指定我到底想要什么.

I post my code inside the onDraw method to specify what exactly I want.

paint.setStyle(Paint.Style.STROKE);
    paint.setStrokeWidth(2);
    paint.setColor(Color.BLACK);

    Path path = new Path();
    path.moveTo(10, 50);   // THIS TRANSFORMATIONS TO BE ANIMATED!!!!!!!!
    path.lineTo(40, 50);
    path.moveTo(40, 50);
    path.lineTo(50, 40);
    // and so on...


    canvas.drawPath(path, paint);

有什么想法吗????

推荐答案

您可以按时间变换画布，即:

You can transform your canvas by time, i.e:

class MyView extends View {

    int framesPerSecond = 60;
    long animationDuration = 10000; // 10 seconds

    Matrix matrix = new Matrix(); // transformation matrix

    Path path = new Path();       // your path
    Paint paint = new Paint();    // your paint

    long startTime;

    public MyView(Context context) {
        super(context);

        // start the animation:
        this.startTime = System.currentTimeMillis();
        this.postInvalidate(); 
    }

    @Override
    protected void onDraw(Canvas canvas) {

        long elapsedTime = System.currentTimeMillis() - startTime;

        matrix.postRotate(30 * elapsedTime/1000);        // rotate 30° every second
        matrix.postTranslate(100 * elapsedTime/1000, 0); // move 100 pixels to the right
        // other transformations...

        canvas.concat(matrix);        // call this before drawing on the canvas!!

        canvas.drawPath(path, paint); // draw on canvas

        if(elapsedTime < animationDuration)
            this.postInvalidateDelayed( 1000 / framesPerSecond);
    }

}

这篇关于如何在画布上动画路径 - android的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！