SunnyUI的Button支持换行

private string _text;
        // 重写 Text 属性
        [Editor("System.ComponentModel.Design.MultilineStringEditor, System.Design, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a", typeof(UITypeEditor))]
        public override string Text
        {
            get { return _text; }
            set
            {
                if (_text != value)
                {
                    _text = value;
                    Invalidate();
                }
            }
        }

public static void DrawString(this Graphics g, string str, Font font, Color color, Size size, Padding padding, ContentAlignment align)
        {
            if (str.IsNullOrEmpty()) return;
            SizeF sf = g.MeasureString(str, font);
            using (Brush br = color.Brush())
            {
                StringFormat stringFormat = new StringFormat
                {
                    Alignment = StringAlignment.Center,
                    LineAlignment = StringAlignment.Center
                };
                stringFormat.FormatFlags = StringFormatFlags.LineLimit;

                switch (align)
                {
                    case ContentAlignment.MiddleCenter:
                        //g.DrawString(str, font, br, padding.Left + (size.Width - sf.Width - padding.Left - padding.Right) / 2.0f,
                        //    padding.Top + (size.Height - sf.Height - padding.Top - padding.Bottom) / 2.0f,stringFormat);
                        RectangleF rect = new RectangleF(0, 0, size.Width, size.Height);
                        g.DrawString(str, font, br, rect, stringFormat);
                        break;

                    case ContentAlignment.TopLeft:
                        g.DrawString(str, font, br, padding.Left, padding.Top);
                        break;

                    case ContentAlignment.TopCenter:
                        g.DrawString(str, font, br, padding.Left + (size.Width - sf.Width - padding.Left - padding.Right) / 2.0f, padding.Top);
                        break;

                    case ContentAlignment.TopRight:
                        g.DrawString(str, font, br, size.Width - sf.Width - padding.Right, padding.Top);
                        break;

                    case ContentAlignment.MiddleLeft:
                        g.DrawString(str, font, br, padding.Left, padding.Top + (size.Height - sf.Height - padding.Top - padding.Bottom) / 2.0f);
                        break;

                    case ContentAlignment.MiddleRight:
                        g.DrawString(str, font, br, size.Width - sf.Width - padding.Right, padding.Top + (size.Height - sf.Height - padding.Top - padding.Bottom) / 2.0f);
                        break;

                    case ContentAlignment.BottomLeft:
                        g.DrawString(str, font, br, padding.Left, size.Height - sf.Height - padding.Bottom);
                        break;

                    case ContentAlignment.BottomCenter:
                        g.DrawString(str, font, br, padding.Left + (size.Width - sf.Width - padding.Left - padding.Right) / 2.0f, size.Height - sf.Height - padding.Bottom);
                        break;

                    case ContentAlignment.BottomRight:
                        g.DrawString(str, font, br, size.Width - sf.Width - padding.Right, size.Height - sf.Height - padding.Bottom);
                        break;
                }
            }
        }