如何在Android中更改画布上绘画的颜色/厚度？

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.View;

public class CustomView extends View {
    private Paint paint;

    public CustomView(Context context) {
        super(context);
        init();
    }

    private void init() {
        paint = new Paint();
        paint.setColor(Color.RED); // 设置颜色为红色
        paint.setStrokeWidth(10); // 设置线条厚度为10像素
        paint.setStyle(Paint.Style.STROKE); // 设置为描边模式
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        // 绘制一条线
        canvas.drawLine(100, 100, 500, 500, paint);

        // 更改颜色和厚度
        paint.setColor(Color.BLUE); // 更改颜色为蓝色
        paint.setStrokeWidth(20); // 更改线条厚度为20像素

        // 绘制另一条线
        canvas.drawLine(100, 200, 500, 200, paint);
    }
}