Android 按钮上的onDraw三角形
在我创建的扩展Android 按钮上的onDraw三角形,android,android-canvas,Android,Android Canvas,在我创建的扩展按钮的类中,我重写了onDraw函数,在按钮的右侧创建一个指向中心的三角形: 相反,我得到的是: 这是我写的: Paint paint = new Paint(); @Override public void onDraw(Canvas canvas) { Paint paint = new Paint(); paint.setColor(android.graphics.Color.BLACK); canvas.drawPaint(paint);
按钮的类中,我重写了onDraw
函数,在按钮的右侧创建一个指向中心的三角形:
相反,我得到的是:
这是我写的:
Paint paint = new Paint();
@Override
public void onDraw(Canvas canvas)
{
Paint paint = new Paint();
paint.setColor(android.graphics.Color.BLACK);
canvas.drawPaint(paint);
paint.setStrokeWidth(4);
paint.setStyle(Paint.Style.FILL_AND_STROKE);
paint.setAntiAlias(true);
Point center = new Point(getWidth()/2, getHeight()/2);
Point a=new Point(getWidth(), 0);;
Point b=new Point(getWidth(), getHeight());;
paint.setColor(Color.RED);
Path path= new Path();
path.setFillType(Path.FillType.EVEN_ODD);
path.lineTo(b.x, b.y);
path.lineTo(center.x, center.y);
path.lineTo(a.x, a.y);
path.close();
canvas.drawPath(path, paint);
}
您忘记移动到初始点
差不多
path.moveTo(point1_draw.x,point1_draw.y);
在第一次lineTo()之前
因为lineTo()
需要一个“最后一点”来开始段
void lineTo(float x, float y) // Add a line from the last point to the specified point (x,y).
因此,最终,您的cod将如下所示:
Path path= new Path();
path.setFillType(Path.FillType.EVEN_ODD);
path.moveTo(a.x, a.y); // Move to a
path.lineTo(center.x, center.y); // Segment from a to center
path.lineTo(b.x, b.y); // Segment from center to b
path.close(); // Segment from b to a
canvas.drawPath(path, paint);