如何在Android中将路径绘制到视图中

Question

大家好，我想在画布上绘制简单的路径线条，应该会绘制出红色矩形和白色线条，但是它什么都没有绘制出来，我错过了什么吗？ 下面是我的代码：

Canvas canvas = new Canvas();


       Paint paint = new Paint();

       paint.setStyle(Paint.Style.FILL);
       paint.setColor(Color.RED);
       canvas.drawPaint(paint);
       Path path = new Path();
       //canvas.drawColor(Color.CYAN);

       for (int i = 5; i < 50; i++) {

           path.moveTo(4, i-1);
           path.lineTo(4, i);

       }
       path.close();

       paint.setStrokeWidth(3);
       paint.setPathEffect(null);
       paint.setColor(Color.WHITE);
       paint.setStyle(Paint.Style.STROKE);

       canvas.drawPath(path, paint);

        for (int i = 0; i < 3; i++) {
            View iview =    inflater.inflate(R.layout.linear_layout, null);
            if(i == 0){
                iview.findViewById(R.id.imageView1).setBackgroundResource(R.drawable.distspeed);
            }
            if(i == 1){
                iview.findViewById(R.id.imageView1).setBackgroundResource(R.drawable.hxmdist);
            }
            if(i == 2){
                iview.findViewById(R.id.imageView1).setBackgroundResource(R.drawable.hxmspeeed);
            }

            iview.draw(canvas);

            realViewSwitcher.addView(iview);
        }

- Csabi

---

不是我自己的问题，但我找到了解决方案，我必须创建自己的视图，在onDraw过程中，我能够绘制出路径。 - Csabi

Answer 1

我只发布可工作的代码：

修改后的活动：

for (int i = 0; i < 2; i++) {

        MyView mView = new MyView(this,i);

        realViewSwitcher.addView(mView);
        }

我的视图:

public class MyView extends View {

    public MyView(Context context, int kolki) {
        super(context);

        if (kolki == 0){
            this.setBackgroundResource(R.drawable.distspeed);
        }
        if (kolki == 1){
            this.setBackgroundResource(R.drawable.hxmdist);
        }
    }

    public void setBackgroundResource (int resid){
        super.setBackgroundResource(resid);
    } 

    public void onDraw(Canvas c){
        super.onDraw(c);
        Paint paint = new Paint();
        Path path = new Path();
        paint.setStyle(Paint.Style.FILL);
        paint.setColor(Color.TRANSPARENT);
        c.drawPaint(paint);
        for (int i = 50; i < 100; i++) {
               path.moveTo(i, i-1);
               path.lineTo(i, i);  
        }
        path.close();
        paint.setStrokeWidth(3);
        paint.setPathEffect(null);
        paint.setColor(Color.BLACK);
        paint.setStyle(Paint.Style.STROKE);
        c.drawPath(path, paint);
    }

}

- Csabi

---

不推荐在onDraw方法中分配对象，应该在构造函数中分配Paint和Path。 - Sir Codesalot