How C # Implements a simple instance of the loading hint control

This article through the instance code to introduce the C # implementation simple loading hint control function, the code is very simple, has the reference value, needs the friend reference next

Draw a Circle control yourself

Using system;using system.collections.generic;using system.componentmodel;using system.data;using System.Drawing; Using system.drawing.drawing2d;using system.linq;using system.text;using system.threading.tasks;using System.windows.forms;namespace exerciseuiprj.controls{public partial class Loadcontrol:control {Color Begincolor    = Color.Blue;    Color endcolor = color.red;    int wid = 10;    int curindex = 0;    Timer timer;    int instervel = 200;    String loadstr = "Loading ....";      Public LoadControl () {InitializeComponent (); SetStyle (Controlstyles.userpaint | Controlstyles.allpaintinginwmpaint|      Controlstyles.optimizeddoublebuffer, True); This.      MinimumSize = new Size (40, 80); if (!      DesignMode) {Start ();        }} public void Start () {if (timer = = NULL) {timer = new timer (); Timer.        Interval = Instervel; Timer.      Tick + = Timer_tick; } timer.    Enabled = true; } public void Stop () {if (Timer! = NULL) {timer.      Enabled = false;      }} void Timer_tick (object sender, EventArgs e) {curindex++; Curindex = Curindex >= wid?      0:curindex;    Refresh (); }//Calculate various circle-related point GetPoint (double D, double R, point center) {int x = (int) (R * Math.Cos (d * math.pi/180      .0));      int y = (int) (R * Math.sin (d * math.pi/180.0)); return new Point (center. x + x, center.    Y-Y);      } GraphicsPath GetPath (point A, point B) {point C, D, E, F;      int h = 2;      Vertical (A, B, H, out C, out D);      Vertical (b, A, h, out E, out F);      GraphicsPath path = new GraphicsPath (); Path.      Addpolygon (new point[] {c, D, E, f}); Path.      Closeallfigures ();    return path; } bool Vertical (Point Pointa, point pointb, Double R, out Point Pointc, out point pointd) {POINTC = new Point (      );      Pointd = new Point ();  try {//(X-XA) ^2+ (y-ya) ^2=r*r distance formula//(X-XA) * (XB-XA) + (Y-ya) * (Yb-ya) =0 Vertical      The solution to the equation is two points for the point var cx = Pointa. X-(POINTB. Y-pointa.        Y) * R/distance (Pointa, POINTB); var cy = Pointa. Y + (POINTB. X-pointa.        X) * R/distance (Pointa, POINTB); var dx = Pointa. X + (POINTB. Y-pointa.        Y) * R/distance (Pointa, POINTB); var dy = Pointa. Y-(POINTB. X-pointa.        X) * R/distance (Pointa, POINTB);        POINTC = new Point ((int) CX, (int) CY);        Pointd = new Point ((int) dx, (int) dy);      return true;      } catch {//if a, b two points coincident will error, then return false to false;      }} double Distance (double xa, double ya, double xb, double yb) {double L;      L = Math.sqrt (Math.pow (XA-XB, 2) + Math.pow (YA-YB, 2));    return L; } Double Distance (point PA, point Pb) {return Distance (Pa. X, Pa. Y, PB. X, PB.    Y);      } GraphicsPath GetPath (double D, Double R, point c) {var p1 = GetPoint (d, r/2.0, C);      var P2 = getpoint (d, R, c);    Return GetPath (P1, p2); }//Gradient gradient color[] GetcoloRS () {int dr = (int) ((ENDCOLOR.R-BEGINCOLOR.R)/(double) wid);      int dg = (int) ((ENDCOLOR.G-BEGINCOLOR.G)/(double) wid);      int db = (int) ((endcolor.b-begincolor.b)/(double) wid);      list<color> colors = new list<color> (); for (int i = 0; i < wid; i++) {colors.      ADD (Color.FromArgb (BEGINCOLOR.R + dr * I, BEGINCOLOR.G + dg * I, BEGINCOLOR.B + db * i)); } return colors.    ToArray ();      }//Draw circle void DrawRect (Graphics g) {int r = (int) (size.height/2.0);      Point Center = new Point (R, R);      var colors = getcolors ();      int findex = Curindex;        for (int i = 0; i < wid; i++) {Double d = (360.0/wid) * i;        var p = GetPath (d, R, center);        int CIndex = Findex + i; CIndex = CIndex >= wid?        Cindex-wid:cindex;      G.fillpath (New SolidBrush (Colors[cindex]), p);    }}//Draw the String void drawstring (Graphics g) {if (size.height >= size.width) return;  Rectangle rect = new Rectangle (new Point (size.height, 0), New Size (Size.width-size.height, size.height));      StringFormat SF = new StringFormat (); sf.      Alignment = Stringalignment.center; sf.      LineAlignment = Stringalignment.center;    g.DrawString (Loadstr, Font, Brushes.black, RECT,SF); } protected override void OnPaint (PaintEventArgs pe) {base.      OnPaint (PE); Graphics g = pe.      Graphics;      G.smoothingmode = smoothingmode.highquality;      G.pixeloffsetmode = pixeloffsetmode.highquality;      DrawRect (g);    DrawString (g); } protected override void Onsizechanged (EventArgs e) {base.      Onsizechanged (e);      if (Size.Height > size.width) {size = new Size (size.height, size.height); }    }  }}

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