C # simple loading prompt control,

C # simple loading prompt control,

Draw a circle control by 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 the Point getPoint (double d, double r, Point center) of various circles {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 Gra PhicsPath (); 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 // obtain two points for solving the equation: 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 and B overlap, an error is returned, and false return 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);} // calculate gradient Color [] getColors () {int dr = (int) (endColor. r-beginColor. r)/(doub Le) 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 ();} // circled void drawRect (Graphics g) {int r = (int) (Size. height/2.0); Point c Enter = 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 );}}}}