【Winform-自定义控件】一个自定义的进度条

0.选择基类

 public class MySlider : Control

1.设置控件的Style

　　在构造函数里添加:

        public MySlider()
        {
            //1.设置控件Style
            this.SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.OptimizedDoubleBuffer | ControlStyles.ResizeRedraw | ControlStyles.UserPaint, true);

            //9.1
        }

2.定义变量，并对一些变量进行一些默认设置

        //2.定义变量，并对一些变量进行一些默认设置
        Rectangle foreRect;
        Rectangle backRect;
        Rectangle setRect;

        Color backgroundColor = Color.White;//背景色
        Color foregroundColor = Color.Gray;//已加载颜色
        Color setRectColor = Color.Black;//控制块
        Color fontColor = Color.Black;//字体颜色

        int maximum = 100; //进度条的最大值
        int minimum = 0;  //进度条的最小值
        double myValue = 0;//当前进度值

        bool showPercent; //显示当前的百分比
        float fontSize = 9;//控件字体的大小
        FontFamily myFontFamily = new FontFamily("宋体"); //控件的字体

3.设置属性值

        //3.设置属性值
        [Category("General"), Description("Show Percent Tag"), Browsable(true)]
        public bool ShowPercentTag
        {
            get { return showPercent; }
            set
            {
                showPercent = value;
                Invalidate();
            }
        }
        [Category("General"), Description("Control's Maximum"), Browsable(true)]
        public int Maximum
        {
            get { return maximum; }
            set
            {
                maximum = value;
                Invalidate();
            }
        }
        [Category("General"), Description("Control's Minimum"), Browsable(true)]
        public int Minimum
        {
            get { return minimum; }
            set
            {
                minimum = value;
                Invalidate();
            }
        }

        [Category("General"), Description("Control's FontSize"), Browsable(true)]
        public float FontSize
        {
            get { return fontSize; }
            set
            {
                this.fontSize = value;
                Invalidate();
            }
        }
        [Category("General"), Description("Control's FontFamily"), Browsable(true)]
        public FontFamily MyFontFamily
        {
            get { return myFontFamily; }
            set
            {
                this.myFontFamily = value;
                Invalidate();
            }
        }

        [Category("Color"), Browsable(true)]
        public Color BackgroundColor
        {
            get { return backgroundColor; }
            set
            {
                this.backgroundColor = value;
                Invalidate();
            }
        }
        [Category("Color"), Browsable(true)]
        public Color ForegroundColor
        {
            get { return foregroundColor; }
            set
            {
                this.foregroundColor = value;
                Invalidate();
            }
        }
        [Category("Color"), Browsable(true)]
        public Color SetRectColor
        {
            get { return setRectColor; }
            set
            {
                this.setRectColor = value;
                Invalidate();
            }
        }
        [Category("Color"), Browsable(true)]
        public Color FontColor
        {
            get { return fontColor; }
            set
            {
                this.fontColor = value;
                Invalidate();
            }
        }

4.确定控件的位置

//4.确定控件的位置，我们根据 Width 和 Height 属性来确定矩形的位置，由于Control 类也有这两个属性，我们在前面加上new覆盖掉原有的属性
        [Category("General"), Description("Control's Width"), Browsable(true)]
        public new int Width
        {
            get { return base.Width; }
            set
            {
                base.Width = value;
                foreRect.X = backRect.X = base.Width / 20;
                backRect.Width = base.Width * 9 / 10;
                foreRect.Width = (int)(myValue / maximum * backRect.Width);
                setRect.X = (int)(myValue / maximum * (backRect.Width - backRect.Height) + foreRect.X);

                Invalidate();
            }
        }
        [Category("General"), Description("Control's Height"), Browsable(true)]
        public new int Height
        {
            get { return base.Height; }
            set
            {
                base.Height = value;
                foreRect.Height = backRect.Height = setRect.Height = setRect.Width = base.Height / 3;
                foreRect.Y = backRect.Y = setRect.Y = base.Height / 3;
                Invalidate();
            }
        }

5.Value值变化的属性

//5.Value值变化的属性。当外部为该事件添加了响应函数时，事件就会生效，否则为OnValueChanged的值为null
        protected EventHandler OnValueChanged;
        public event EventHandler ValueChanged
        {
            add
            {
                if (OnValueChanged != null)
                {
                    foreach (Delegate d in OnValueChanged.GetInvocationList())
                    {
                        if (object.ReferenceEquals(d, value)) { return; }
                    }
                }
                OnValueChanged = (EventHandler)Delegate.Combine(OnValueChanged, value);
            }
            remove
            {
                OnValueChanged = (EventHandler)Delegate.Remove(OnValueChanged, value);
            }
        }

6.定义value属性值

//6.定义Value的值。当Value值改变的时候,重新设置矩形的进度，控制块的位置，并且重绘控件
        //注意：Value属性内如果对进度条的值进行修改，使用myValue变量，而在其他地方，则用Value属性
        [Category("General"), Description("Control's Value"), Browsable(true)]
        public double Value
        {
            get { return myValue; }
            set
            {
                if (myValue < Minimum)
                    throw new ArgumentException("小于最小值");
                if (myValue > Maximum)
                    throw new ArgumentException("超过最大值");

                myValue = value;
                foreRect.Width = (int)(myValue / maximum * backRect.Width);
                setRect.X = (int)(myValue / maximum * (backRect.Width - backRect.Height) + backRect.X);

                if ((myValue - maximum) > 0)
                {
                    foreRect.Width = backRect.Width;
                    setRect.X = backRect.Width - backRect.Height + backRect.X;
                }

                //如果添加了响应函数,则执行该函数
                if (OnValueChanged != null)
                {
                    OnValueChanged(this, EventArgs.Empty);
                }

                Invalidate();
            }
        }

7.绘制控件

        //7.绘制控件，重载OnPaint方法对控件进行绘制
        protected override void OnPaint(PaintEventArgs pe)
        {
            base.OnPaint(pe);

            DrawRect(pe.Graphics);
            DrawText(pe.Graphics);
        }

        private void DrawRect(Graphics e)
        {
            Pen pen = new Pen(this.foregroundColor);

            e.FillRectangle(new SolidBrush(this.backgroundColor), backRect);
            e.DrawRectangle(new Pen(Color.Black), backRect);

            e.FillRectangle(new SolidBrush(this.foregroundColor), foreRect);
            e.DrawRectangle(new Pen(Color.Black), foreRect);

            e.FillRectangle(new SolidBrush(this.setRectColor), setRect);
            e.DrawRectangle(new Pen(Color.Black), setRect);
        }
        private void DrawText(Graphics e)
        {
            Point point = new Point();
            point.X = this.backRect.X + this.backRect.Width * 3 / 7;
            point.Y = this.backRect.Y + this.backRect.Height / 3;

            SolidBrush brush = new SolidBrush(fontColor);
            Font font = new Font(myFontFamily, this.fontSize);
            string percent = ((int)this.myValue).ToString() + "%";

            //通过设置StringFormat可以让文字居中显示
            StringFormat format = new StringFormat();
            format.Alignment = StringAlignment.Center;
            format.LineAlignment = StringAlignment.Center;

            e.DrawString(percent, font, brush, backRect, format);
        }

8.在设计时，修改控件的大小

 //8.最后还有一个方法OnResize，在设计时，修改控件的大小会调用这个方法，比如：拖动边缘的箭头改变控件的大小时，控件也要做相应的改变时，就可以重载该方法，如果没有重载，就只有在修改完成后才更新控件，不懂的可以自己试一下 
        protected override void OnResize(EventArgs e)
        {
            base.OnResize(e);
            this.Width = Width;
            this.Height = Height;
            Invalidate();
        }

9.1响应鼠标事件

        public MySlider()
        {
            //1.设置控件Style

            //9.1.控件绘制完了，却不能操作，还要对控件进行操作
            //通过三个鼠标事件函数，让鼠标可以拖动控制条
            this.MouseDown += MySlider_MouseDown;
            this.MouseMove += MySlider_MouseMove;
            this.MouseUp += MySlider_MouseUp;
        }

9.2响应鼠标事件

        //9.2.添加三个辅助变量，添加响应函数
        Point originPoint;
        Point originsetRectPoint;
        bool setRectDown = false;

        void MySlider_MouseUp(object sender, MouseEventArgs e)
        {
            setRectDown = false;
        }
        void MySlider_MouseMove(object sender, MouseEventArgs e)
        {
            if (setRectDown)
            {
                int dd = e.Location.X - originPoint.X;

                double percent = (double)(originsetRectPoint.X + dd - this.backRect.X) / (this.backRect.Width - this.backRect.Height);
                if (percent < 0)
                {
                    this.Value = minimum;
                    this.foreRect.Width = 0;
                    this.setRect.X = backRect.X;
                }
                else if (percent > 1)
                {
                    this.Value = maximum;
                    this.foreRect.Width = this.backRect.Width;
                    this.setRect.X = backRect.X + backRect.Width - backRect.Height;
                }
                else
                {
                    this.Value = percent * maximum;
                    this.foreRect.Width = (int)(percent * this.backRect.Width);
                    this.setRect.X = originsetRectPoint.X + dd;
                }
                Invalidate();
            }
        }
        void MySlider_MouseDown(object sender, MouseEventArgs e)
        {
            if (setRect.Contains(e.Location))
            {
                this.originPoint = e.Location;
                originsetRectPoint = this.setRect.Location;
                this.setRectDown = true;
            }
        }