绘制从点1(X1,Y1)到POINT2(X2,Y2)的箭头这样 绘制带箭头的曲线线在机器人画布
曲线我正在开发的Android在帆布的应用程序。 像应用程序自动机,我在最后绘制曲线与箭头的麻烦。指向下一个圆的 。
你能给我一个关于这个的代码或建议吗?
绘制从点1(X1,Y1)到POINT2(X2,Y2)的箭头这样 绘制带箭头的曲线线在机器人画布
曲线我正在开发的Android在帆布的应用程序。 像应用程序自动机,我在最后绘制曲线与箭头的麻烦。指向下一个圆的 。
你能给我一个关于这个的代码或建议吗?
我认为你需要的是在路径和线条画上混合绘制。声明这个方法您的onDraw里面:
private void drawOvalAndArrow(Canvas canvas){
Paint circlePaint = new Paint();
circlePaint.setStyle(Paint.Style.FILL_AND_STROKE);
circlePaint.setAntiAlias(true);
circlePaint.setStrokeWidth(2);
circlePaint.setColor(Color.CYAN);
float centerWidth = canvas.getWidth()/2; //get center x of display
float centerHeight = canvas.getHeight()/2; //get center y of display
float circleRadius = 20; //set radius
float circleDistance = 200; //set distance between both circles
//draw circles
canvas.drawCircle(centerWidth, centerHeight, circleRadius, circlePaint);
canvas.drawCircle(centerWidth+circleDistance, centerHeight, circleRadius, circlePaint);
//to draw an arrow, just lines needed, so style is only STROKE
circlePaint.setStyle(Paint.Style.STROKE);
circlePaint.setColor(Color.RED);
//create a path to draw on
Path arrowPath = new Path();
//create an invisible oval. the oval is for "behind the scenes" ,to set the path´
//area. Imagine this is an egg behind your circles. the circles are in the middle of this egg
final RectF arrowOval = new RectF();
arrowOval.set(centerWidth,
centerHeight-80,
centerWidth + circleDistance,
centerHeight+80);
//add the oval to path
arrowPath.addArc(arrowOval,-180,180);
//draw path on canvas
canvas.drawPath(arrowPath, circlePaint);
//draw arrowhead on path start
arrowPath.moveTo(centerWidth,centerHeight); //move to the center of first circle
arrowPath.lineTo(centerWidth-circleRadius, centerHeight-circleRadius);//draw the first arrowhead line to the left
arrowPath.moveTo(centerWidth,centerHeight);//move back to the center
arrowPath.lineTo(centerWidth+circleRadius, centerHeight-circleRadius);//draw the next arrowhead line to the right
//same as above on path end
arrowPath.moveTo(centerWidth+circleDistance,centerHeight);
arrowPath.lineTo((centerWidth+circleDistance)-circleRadius, centerHeight-circleRadius);
arrowPath.moveTo(centerWidth+circleDistance,centerHeight);
arrowPath.lineTo((centerWidth+circleDistance)+circleRadius, centerHeight-circleRadius);
//draw the path
canvas.drawPath(arrowPath,circlePaint);
}
这仅仅是一个坏榜样,但itshould显示从哪里开始。
我知道我应该留下评论,但评论中的代码很难阅读,所以我提出了另一个答案。 答案Opiatefuchs它基本上是正确的。但有一件事你应该注意,如果你想测试他的代码。
float centerWidth = canvas.getWidth()/2; //get center x of display
float centerHeight = canvas.getHeight()/2; //get center y of display
centerWidth和centerHeight应该像下面那样获得,否则什么都不会涂在你的屏幕上。 和circleDistance = 200对于普通手机的屏幕有点大(对于我的设备三星i9300来说,200太大,第二个圆定位在屏幕范围外,例如将其更改为更小的值80)。
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
centerWidth = w/2;
centerHeight = h/2;
}
的截图。
如果您使用的是画布,你可以使用http://developer.android.com/reference/android/graphics/Canvas.html#drawArc(android.graphics.RectF,浮球,浮球,布尔,android.graphics.Paint),但你将不得不创建辅助方法手动在圆弧的开始和结束绘制两个箭头线。 – Shellum 2013-03-13 18:14:15