.NET饼图：如何向切片添加文本和旋转图表-.NETpiechart:howtoaddtexttoslicesandrotatechart

To add text labels, call g.DrawString.

要添加文本标签,请调用g.DrawString。

EDIT: To make the textvertical like your image, rotate the Graphics object to angle + sweep / 2, and draw your text. To make it draw downward, yopu may be able to draw it in a small width and rely on character wrapping; if that doesn't work, draw it character vy chaaracter and use g.MeasureString to figure out where to put the next character.

编辑:要使textvertical像图像一样,将Graphics对象旋转到angle + sweep / 2,然后绘制文本。为了使它向下绘制,yopu可能能够以小的宽度绘制它并依靠字符包裹;如果这不起作用,绘制字符vy chaaracter并使用g.MeasureString来确定下一个字符的放置位置。

To rotate the entire chart, call g.RotateTransform with an angle in degrees before drawing it. EDIT: like this:

要旋转整个图表,请在绘制之前以度数角度调用g.RotateTransform。编辑:像这样:

    private void DrawPieChart()
    {
        Graphics g = this.CreateGraphics();
        g.Clear(this.BackColor);
        Rectangle rect = new Rectangle(0, 0, 300, 300);
        float angle = 0;
        Random random = new Random();
        int sectors = 24;
        int sweep = 360 / sectors;

         g.RotateTransform(90);        //Rotates by 90 degrees
         for(int i=0; i<24;i++)
        {
            Color clr = Color.FromArgb(random.Next(0, 255),random.Next(0, 255), random.Next(0, 255));
            g.FillPie(new SolidBrush(clr), rect, angle, sweep);
            angle += sweep;
        }
        g.Dispose();
    }

TO animate the rotation, make a field for the angle, increment it on a timer, and pass the field to g.RotateTransform.

要为旋转设置动画,请为角度创建一个字段,在计时器上增加该字段,然后将该字段传递给g.RotateTransform。

Also, the correct way to draw things is to handle the control's Paint event, and draw using e.Graphics. Then, when you want to redraw it, call Invalidate. To prevent flickering, call this.SetStyle(ControlStyles.DoubleBuffer, true); in the constructor.

另外,绘制事物的正确方法是处理控件的Paint事件,并使用e.Graphics绘制。然后,当您想重绘它时,请调用Invalidate。要防止闪烁,请调用this.SetStyle(ControlStyles.DoubleBuffer,true);在构造函数中。