将静态方法添加到当前的自定义类

问题描述

我有自定义进度条（是带有文本的进度条）

public enum ProgressBardisplayText
    {
        Percentage,CustomText
    }

    public class CustomProgressBar : ProgressBar
    {


        [DllImportAttribute("uxtheme.dll")]
        private static extern int SetwindowTheme(IntPtr hWnd,string appname,string idlist);

        protected override void OnHandleCreated(EventArgs e)
        {
            SetwindowTheme(this.Handle,"","");
            base.OnHandleCreated(e);
        }

        //Property to set to decide whether to print a % or Text
        public ProgressBardisplayText displayStyle { get; set; }

        //Property to hold the custom text
        public String CustomText { get; set; }

        public CustomProgressBar()
        {
            // Modify the ControlStyles flags
            //http://msdn.microsoft.com/en-us/library/system.windows.forms.controlstyles.aspx
            SetStyle(ControlStyles.UserPaint | ControlStyles.AllPaintingInWmPaint,true);
            SetStyle(ControlStyles.OptimizedDoubleBuffer,true);
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            Rectangle rect = ClientRectangle;
            Graphics g = e.Graphics;

            ProgressBarRenderer.DrawHorizontalBar(g,rect);
            rect.Inflate(-3,-3);
            if (Value > 0)
            {
                // As we doing this ourselves we need to draw the chunks on the progress bar
                Rectangle clip = new Rectangle(rect.X,rect.Y,(int)Math.Round(((float)Value / Maximum) * rect.Width),rect.Height);
                ProgressBarRenderer.DrawHorizontalChunks(g,clip);
            }

            // Set the display text (Either a % amount or our custom text
            int percent = (int)(((double)this.Value / (double)this.Maximum) * 100);
            string text = displayStyle == ProgressBardisplayText.Percentage ? percent.ToString() + '%' : CustomText;

            //string text = displayStyle == ProgressBardisplayText.Percentage ? Value.ToString() + '%' : CustomText;


            using (Font f = new Font(FontFamily.GenericSerif,10,FontStyle.Bold))
            {

                Sizef len = g.MeasureString(text,f);
                // Calculate the location of the text (the middle of progress bar)
                // Point location = new Point(Convert.ToInt32((rect.Width / 2) - (len.Width / 2)),Convert.ToInt32((rect.Height / 2) - (len.Height / 2)));
                Point location = new Point(Convert.ToInt32((Width / 2) - len.Width / 2),Convert.ToInt32((Height / 2) - len.Height / 2));
                // The commented-out code will centre the text into the highlighted area only. This will centre the text regardless of the highlighted area.
                // Draw the custom text
                g.DrawString(text,f,Brushes.Black,location);
            }

        }
    }

现在我想更改进度条的颜色，所以我看到了这个solution

所以我尝试添加到我的代码中

  [DllImport("user32.dll",CharSet = CharSet.Auto,SetLastError = false)]
  static extern IntPtr SendMessage(IntPtr hWnd,uint Msg,IntPtr w,IntPtr l);
    public static void SetState(this ProgressBar pBar,int state)
    {
        SendMessage(pBar.Handle,1040,(IntPtr)state,IntPtr.Zero);
    }

但是如您所见，此代码用于扩展方法，但是我当前的CustomProgressBar继承了ProgressBar，并且不允许使用静态类。所以把我扔了：

扩展方法必须在非通用静态类中定义

如何将此方法添加到当前类中？问候

解决方法

这是一个扩展方法，那些需要进入静态类。如果您只想使其在现有的非静态类中运行，则只需删除第一个参数上的this：

[DllImport("user32.dll",CharSet = CharSet.Auto,SetLastError = false)]
static extern IntPtr SendMessage(IntPtr hWnd,uint Msg,IntPtr w,IntPtr l);

public static void SetState(ProgressBar pBar,int state)
{
    SendMessage(pBar.Handle,1040,(IntPtr)state,IntPtr.Zero);
}

由于ProgressBar继承自该参数，因此该参数仍可以为CustomProgressBar类型。

c#c#custom-controls winforms