本文通過實例代碼給大家介紹了C#實現簡單的loading提示控制項功能，代碼非常簡單，具有參考借鑑價值，需要的朋友參考下吧
自己畫一個轉圈圈的控制項
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();
}
//計算各種圈圈相關
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 距離公式
//(X-xa)*(xb-xa)+(Y-ya)*(yb-ya)=0 垂直
//解方程得兩點即為所求點
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
{
//如果A,B兩點重合會報錯，那樣就返回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);
}
//算漸變色
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
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();
}
//畫圈圈
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);
}
}
//畫字符串
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);
}
}
}
}
總結
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