Question

嗯，首先尝试的是一个易于制作的纺车（gif）。之后，我找到了一个动态生成轮子的代码，但在这两种情况下都无法完全透明。

根据我设置为父级（窗体或面板）的内容以及我在方向盘上的位置，旋转只是透明的一半。

我使用C＃express（VS 2008）。

我想要的只是一个漂亮的轮子在窗体中心，当BG正在做某事时激活，但完全透明，所以我可以调整窗体大小。

谢谢，

更新：我研究了一些可以画出旋转轮的代码。几乎没有工作，除了OnPantBackground（）需要为空以后面绘制，但在这种情况下，由于启用了ControlStyles.OptimizedDoubleBuffer而绘制了一个黑色矩形。

有什么建议吗？谢谢。

using System;
using System.Drawing;
using System.Windows.Forms;
using System.ComponentModel;
using System.Drawing.Drawing2D;

namespace WinFormsControls
{
    /// <summary>
    /// A label that can be transparent.
    /// </summary>
    public class TransparentLabel : Control
    {
        // Constants =========================================================
        private const double NumberOfDegreesInCircle = 360;
        private const double NumberOfDegreesInHalfCircle = NumberOfDegreesInCircle / 2;
        private const int DefaultInnerCircleRadius = 8;
        private const int DefaultOuterCircleRadius = 10;
        private const int DefaultNumberOfSpoke = 10;
        private const int DefaultSpokeThickness = 4;
        private readonly Color DefaultColor = Color.DarkGray;

        private const int MacOSXInnerCircleRadius = 5;
        private const int MacOSXOuterCircleRadius = 11;
        private const int MacOSXNumberOfSpoke = 12;
        private const int MacOSXSpokeThickness = 2;

        private const int FireFoxInnerCircleRadius = 6;
        private const int FireFoxOuterCircleRadius = 7;
        private const int FireFoxNumberOfSpoke = 9;
        private const int FireFoxSpokeThickness = 4;

        private const int IE7InnerCircleRadius = 8;
        private const int IE7OuterCircleRadius = 9;
        private const int IE7NumberOfSpoke = 24;
        private const int IE7SpokeThickness = 4;

        // Enumeration =======================================================
        public enum StylePresets
        {
            MacOSX,
            Firefox,
            IE7,
            Custom
        }

        // Attributes ========================================================
        private Timer m_Timer;
        private bool m_IsTimerActive;
        private int m_NumberOfSpoke;
        private int m_SpokeThickness;
        private int m_ProgressValue;
        private int m_OuterCircleRadius;
        private int m_InnerCircleRadius;
        private PointF m_CenterPoint;
        private Color m_Color;
        private Color[] m_Colors;
        private double[] m_Angles;
        private StylePresets m_StylePreset;

        // Properties ========================================================
        /// <summary>
        /// Gets or sets the lightest color of the circle.
        /// </summary>
        /// <value>The lightest color of the circle.</value>
        [TypeConverter("System.Drawing.ColorConverter"),
         Category("LoadingCircle"),
         Description("Sets the color of spoke.")]
        public Color Color
        {
            get
            {
                return m_Color;
            }
            set
            {
                m_Color = value;

                GenerateColorsPallet();
                Invalidate();
            }
        }

        /// <summary>
        /// Gets or sets the outer circle radius.
        /// </summary>
        /// <value>The outer circle radius.</value>
        [System.ComponentModel.Description("Gets or sets the radius of outer circle."),
         System.ComponentModel.Category("LoadingCircle")]
        public int OuterCircleRadius
        {
            get
            {
                if (m_OuterCircleRadius == 0)
                    m_OuterCircleRadius = DefaultOuterCircleRadius;

                return m_OuterCircleRadius;
            }
            set
            {
                m_OuterCircleRadius = value;
                Invalidate();
            }
        }

        /// <summary>
        /// Gets or sets the inner circle radius.
        /// </summary>
        /// <value>The inner circle radius.</value>
        [System.ComponentModel.Description("Gets or sets the radius of inner circle."),
         System.ComponentModel.Category("LoadingCircle")]
        public int InnerCircleRadius
        {
            get
            {
                if (m_InnerCircleRadius == 0)
                    m_InnerCircleRadius = DefaultInnerCircleRadius;

                return m_InnerCircleRadius;
            }
            set
            {
                m_InnerCircleRadius = value;
                Invalidate();
            }
        }

        /// <summary>
        /// Gets or sets the number of spoke.
        /// </summary>
        /// <value>The number of spoke.</value>
        [System.ComponentModel.Description("Gets or sets the number of spoke."),
        System.ComponentModel.Category("LoadingCircle")]
        public int NumberSpoke
        {
            get
            {
                if (m_NumberOfSpoke == 0)
                    m_NumberOfSpoke = DefaultNumberOfSpoke;

                return m_NumberOfSpoke;
            }
            set
            {
                if (m_NumberOfSpoke != value && m_NumberOfSpoke > 0)
                {
                    m_NumberOfSpoke = value;
                    GenerateColorsPallet();
                    GetSpokesAngles();

                    Invalidate();
                }
            }
        }

        /// <summary>
        /// Gets or sets a value indicating whether this <see cref="T:LoadingCircle"/> is active.
        /// </summary>
        /// <value><c>true</c> if active; otherwise, <c>false</c>.</value>
        [System.ComponentModel.Description("Gets or sets the number of spoke."),
        System.ComponentModel.Category("LoadingCircle")]
        public bool Active
        {
            get
            {
                return m_IsTimerActive;
            }
            set
            {
                m_IsTimerActive = value;
                ActiveTimer();
            }
        }

        /// <summary>
        /// Gets or sets the spoke thickness.
        /// </summary>
        /// <value>The spoke thickness.</value>
        [System.ComponentModel.Description("Gets or sets the thickness of a spoke."),
        System.ComponentModel.Category("LoadingCircle")]
        public int SpokeThickness
        {
            get
            {
                if (m_SpokeThickness <= 0)
                    m_SpokeThickness = DefaultSpokeThickness;

                return m_SpokeThickness;
            }
            set
            {
                m_SpokeThickness = value;
                Invalidate();
            }
        }

        /// <summary>
        /// Gets or sets the rotation speed.
        /// </summary>
        /// <value>The rotation speed.</value>
        [System.ComponentModel.Description("Gets or sets the rotation speed. Higher the slower."),
        System.ComponentModel.Category("LoadingCircle")]
        public int RotationSpeed
        {
            get
            {
                return m_Timer.Interval;
            }
            set
            {
                if (value > 0)
                    m_Timer.Interval = value;
            }
        }

        /// <summary>
        /// Quickly sets the style to one of these presets, or a custom style if desired
        /// </summary>
        /// <value>The style preset.</value>
        [Category("LoadingCircle"),
         Description("Quickly sets the style to one of these presets, or a custom style if desired"),
         DefaultValue(typeof(StylePresets), "Custom")]
        public StylePresets StylePreset
        {
            get { return m_StylePreset; }
            set
            {
                m_StylePreset = value;

                switch (m_StylePreset)
                {
                    case StylePresets.MacOSX:
                        SetCircleAppearance(MacOSXNumberOfSpoke,
                            MacOSXSpokeThickness, MacOSXInnerCircleRadius,
                            MacOSXOuterCircleRadius);
                        break;
                    case StylePresets.Firefox:
                        SetCircleAppearance(FireFoxNumberOfSpoke,
                            FireFoxSpokeThickness, FireFoxInnerCircleRadius,
                            FireFoxOuterCircleRadius);
                        break;
                    case StylePresets.IE7:
                        SetCircleAppearance(IE7NumberOfSpoke,
                            IE7SpokeThickness, IE7InnerCircleRadius,
                            IE7OuterCircleRadius);
                        break;
                    case StylePresets.Custom:
                        SetCircleAppearance(DefaultNumberOfSpoke,
                            DefaultSpokeThickness,
                            DefaultInnerCircleRadius,
                            DefaultOuterCircleRadius);
                        break;
                }
            }
        }


        /// <summary>
        /// Creates a new <see cref="TransparentLabel"/> instance.
        /// </summary>
        public TransparentLabel()
        {
            TabStop = false;

            InitializeComponent();

            SetStyle(ControlStyles.UserPaint, true);
            //SetStyle(ControlStyles.OptimizedDoubleBuffer, true);
            SetStyle(ControlStyles.ResizeRedraw, true);
            SetStyle(ControlStyles.SupportsTransparentBackColor, true);

            m_Color = DefaultColor;

            GenerateColorsPallet();
            GetSpokesAngles();
            GetControlCenterPoint();

            m_Timer = new Timer();
            m_Timer.Tick += new EventHandler(aTimer_Tick);
            ActiveTimer();

            this.Resize += new EventHandler(LoadingCircle_Resize);

            this.DoubleBuffered = true;
            this.SetStyle(ControlStyles.UserPaint |
                          ControlStyles.AllPaintingInWmPaint |
                          ControlStyles.ResizeRedraw |
                          ControlStyles.ContainerControl |
                          ControlStyles.OptimizedDoubleBuffer |
                          ControlStyles.SupportsTransparentBackColor
                          , true);


        }

        // Events ============================================================
        /// <summary>
        /// Handles the Resize event of the LoadingCircle control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="T:System.EventArgs"/> instance containing the event data.</param>
        void LoadingCircle_Resize(object sender, EventArgs e)
        {
            GetControlCenterPoint();
        }

        /// <summary>
        /// Handles the Tick event of the aTimer control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="T:System.EventArgs"/> instance containing the event data.</param>
        void aTimer_Tick(object sender, EventArgs e)
        {
            m_ProgressValue = ++m_ProgressValue % m_NumberOfSpoke;
            Invalidate();
        }

        /// <summary>
        /// Gets the creation parameters.
        /// </summary>
        protected override CreateParams CreateParams
        {
            get
            {
                CreateParams cp = base.CreateParams;
                cp.ExStyle |= 0x20;
                return cp;
            }
        }



        // Overridden Methods ================================================
        /// <summary>
        /// Retrieves the size of a rectangular area into which a control can be fitted.
        /// </summary>
        /// <param name="proposedSize">The custom-sized area for a control.</param>
        /// <returns>
        /// An ordered pair of type <see cref="T:System.Drawing.Size"></see> representing the width and height of a rectangle.
        /// </returns>
        public override Size GetPreferredSize(Size proposedSize)
        {
            proposedSize.Width =
                (m_OuterCircleRadius + m_SpokeThickness) * 2;

            return proposedSize;
        }

        /// <summary>
        /// Paints the background.
        /// </summary>
        /// <param name="e">E.</param>
        /// 

        protected override void OnPaintBackground(PaintEventArgs e)
        {
            // do nothing
        }

        /// <summary>
        /// Paints the control.
        /// </summary>
        /// <param name="e">E.</param>
        protected override void OnPaint(PaintEventArgs e)
        {
            //DrawText();


            if (m_NumberOfSpoke > 0)
            {
                e.Graphics.SmoothingMode = SmoothingMode.HighQuality;

                int intPosition = m_ProgressValue;
                for (int intCounter = 0; intCounter < m_NumberOfSpoke; intCounter++)
                {
                    intPosition = intPosition % m_NumberOfSpoke;
                    DrawLine(e.Graphics,
                             GetCoordinate(m_CenterPoint, m_InnerCircleRadius, m_Angles[intPosition]),
                             GetCoordinate(m_CenterPoint, m_OuterCircleRadius, m_Angles[intPosition]),
                             m_Colors[intCounter], m_SpokeThickness);
                    intPosition++;
                }
            }


            base.OnPaint(e);


        }

        /*
        protected override void WndProc(ref Message m)
        {
            base.WndProc(ref m);
            if (m.Msg == 0x000F)
            {
                DrawText();
            }
        }

        private void DrawText()
        {
            using (Graphics graphics = CreateGraphics())
            using (SolidBrush brush = new SolidBrush(ForeColor))
            {
                SizeF size = graphics.MeasureString(Text, Font);

                // first figure out the top
                float top = 0;
                switch (textAlign)
                {
                    case ContentAlignment.MiddleLeft:
                    case ContentAlignment.MiddleCenter:
                    case ContentAlignment.MiddleRight:
                        top = (Height - size.Height) / 2;
                        break;
                    case ContentAlignment.BottomLeft:
                    case ContentAlignment.BottomCenter:
                    case ContentAlignment.BottomRight:
                        top = Height - size.Height;
                        break;
                }

                float left = -1;
                switch (textAlign)
                {
                    case ContentAlignment.TopLeft:
                    case ContentAlignment.MiddleLeft:
                    case ContentAlignment.BottomLeft:
                        if (RightToLeft == RightToLeft.Yes)
                            left = Width - size.Width;
                        else
                            left = -1;
                        break;
                    case ContentAlignment.TopCenter:
                    case ContentAlignment.MiddleCenter:
                    case ContentAlignment.BottomCenter:
                        left = (Width - size.Width) / 2;
                        break;
                    case ContentAlignment.TopRight:
                    case ContentAlignment.MiddleRight:
                    case ContentAlignment.BottomRight:
                        if (RightToLeft == RightToLeft.Yes)
                            left = -1;
                        else
                            left = Width - size.Width;
                        break;
                }
                graphics.DrawString(Text, Font, brush, left, top);
            }
        }
         */
        /*
        /// <summary>
        /// Gets or sets the text associated with this control.
        /// </summary>
        /// <returns>
        /// The text associated with this control.
        /// </returns>
        public override string Text
        {
            get
            {
                return base.Text;
            }
            set
            {
                base.Text = value;
                RecreateHandle();
            }
        }

        /// <summary>
        /// Gets or sets a value indicating whether control's elements are aligned to support locales using right-to-left fonts.
        /// </summary>
        /// <value></value>
        /// <returns>
        /// One of the <see cref="T:System.Windows.Forms.RightToLeft"/> values. The default is <see cref="F:System.Windows.Forms.RightToLeft.Inherit"/>.
        /// </returns>
        /// <exception cref="T:System.ComponentModel.InvalidEnumArgumentException">
        /// The assigned value is not one of the <see cref="T:System.Windows.Forms.RightToLeft"/> values.
        /// </exception>
        public override RightToLeft RightToLeft
        {
            get
            {
                return base.RightToLeft;
            }
            set
            {
                base.RightToLeft = value;
                RecreateHandle();
            }
        }

        /// <summary>
        /// Gets or sets the font of the text displayed by the control.
        /// </summary>
        /// <value></value>
        /// <returns>
        /// The <see cref="T:System.Drawing.Font"/> to apply to the text displayed by the control. The default is the value of the <see cref="P:System.Windows.Forms.Control.DefaultFont"/> property.
        /// </returns>
        public override Font Font
        {
            get
            {
                return base.Font;
            }
            set
            {
                base.Font = value;
                RecreateHandle();
            }
        }

        private ContentAlignment textAlign = ContentAlignment.TopLeft;
        /// <summary>
        /// Gets or sets the text alignment.
        /// </summary>
        public ContentAlignment TextAlign
        {
            get { return textAlign; }
            set
            {
                textAlign = value;
                RecreateHandle();
            }
        }
        */
        private void InitializeComponent()
        {
            this.SuspendLayout();
            this.ResumeLayout(false);

        }


        // Methods ===========================================================
        /// <summary>
        /// Darkens a specified color.
        /// </summary>
        /// <param name="_objColor">Color to darken.</param>
        /// <param name="_intPercent">The percent of darken.</param>
        /// <returns>The new color generated.</returns>
        private Color Darken(Color _objColor, int _intPercent)
        {
            int intRed = _objColor.R;
            int intGreen = _objColor.G;
            int intBlue = _objColor.B;
            return Color.FromArgb(_intPercent, Math.Min(intRed, byte.MaxValue), Math.Min(intGreen, byte.MaxValue), Math.Min(intBlue, byte.MaxValue));
        }

        /// <summary>
        /// Generates the colors pallet.
        /// </summary>
        private void GenerateColorsPallet()
        {
            m_Colors = GenerateColorsPallet(m_Color, Active, m_NumberOfSpoke);
        }

        /// <summary>
        /// Generates the colors pallet.
        /// </summary>
        /// <param name="_objColor">Color of the lightest spoke.</param>
        /// <param name="_blnShadeColor">if set to <c>true</c> the color will be shaded on X spoke.</param>
        /// <returns>An array of color used to draw the circle.</returns>
        private Color[] GenerateColorsPallet(Color _objColor, bool _blnShadeColor, int _intNbSpoke)
        {
            Color[] objColors = new Color[NumberSpoke];

            // Value is used to simulate a gradient feel... For each spoke, the 
            // color will be darken by value in intIncrement.
            byte bytIncrement = (byte)(byte.MaxValue / NumberSpoke);

            //Reset variable in case of multiple passes
            byte PERCENTAGE_OF_DARKEN = 0;

            for (int intCursor = 0; intCursor < NumberSpoke; intCursor++)
            {
                if (_blnShadeColor)
                {
                    if (intCursor == 0 || intCursor < NumberSpoke - _intNbSpoke)
                        objColors[intCursor] = _objColor;
                    else
                    {
                        // Increment alpha channel color
                        PERCENTAGE_OF_DARKEN += bytIncrement;

                        // Ensure that we don't exceed the maximum alpha
                        // channel value (255)
                        if (PERCENTAGE_OF_DARKEN > byte.MaxValue)
                            PERCENTAGE_OF_DARKEN = byte.MaxValue;

                        // Determine the spoke forecolor
                        objColors[intCursor] = Darken(_objColor, PERCENTAGE_OF_DARKEN);
                    }
                }
                else
                    objColors[intCursor] = _objColor;
            }

            return objColors;
        }

        /// <summary>
        /// Gets the control center point.
        /// </summary>
        private void GetControlCenterPoint()
        {
            m_CenterPoint = GetControlCenterPoint(this);
        }

        /// <summary>
        /// Gets the control center point.
        /// </summary>
        /// <returns>PointF object</returns>
        private PointF GetControlCenterPoint(Control _objControl)
        {
            return new PointF(_objControl.Width / 2, _objControl.Height / 2 - 1);
        }

        /// <summary>
        /// Draws the line with GDI+.
        /// </summary>
        /// <param name="_objGraphics">The Graphics object.</param>
        /// <param name="_objPointOne">The point one.</param>
        /// <param name="_objPointTwo">The point two.</param>
        /// <param name="_objColor">Color of the spoke.</param>
        /// <param name="_intLineThickness">The thickness of spoke.</param>
        private void DrawLine(Graphics _objGraphics, PointF _objPointOne, PointF _objPointTwo,
                              Color _objColor, int _intLineThickness)
        {
            using (Pen objPen = new Pen(new SolidBrush(_objColor), _intLineThickness))
            {
                objPen.StartCap = LineCap.Round;
                objPen.EndCap = LineCap.Round;
                _objGraphics.DrawLine(objPen, _objPointOne, _objPointTwo);
            }
        }

        /// <summary>
        /// Gets the coordinate.
        /// </summary>
        /// <param name="_objCircleCenter">The Circle center.</param>
        /// <param name="_intRadius">The radius.</param>
        /// <param name="_dblAngle">The angle.</param>
        /// <returns></returns>
        private PointF GetCoordinate(PointF _objCircleCenter, int _intRadius, double _dblAngle)
        {
            double dblAngle = Math.PI * _dblAngle / NumberOfDegreesInHalfCircle;

            return new PointF(_objCircleCenter.X + _intRadius * (float)Math.Cos(dblAngle),
                              _objCircleCenter.Y + _intRadius * (float)Math.Sin(dblAngle));
        }

        /// <summary>
        /// Gets the spokes angles.
        /// </summary>
        private void GetSpokesAngles()
        {
            m_Angles = GetSpokesAngles(NumberSpoke);
        }

        /// <summary>
        /// Gets the spoke angles.
        /// </summary>
        /// <param name="_shtNumberSpoke">The number spoke.</param>
        /// <returns>An array of angle.</returns>
        private double[] GetSpokesAngles(int _intNumberSpoke)
        {
            double[] Angles = new double[_intNumberSpoke];
            double dblAngle = (double)NumberOfDegreesInCircle / _intNumberSpoke;

            for (int shtCounter = 0; shtCounter < _intNumberSpoke; shtCounter++)
                Angles[shtCounter] = (shtCounter == 0 ? dblAngle : Angles[shtCounter - 1] + dblAngle);

            return Angles;
        }

        /// <summary>
        /// Actives the timer.
        /// </summary>
        private void ActiveTimer()
        {
            if (m_IsTimerActive)
            {
                m_Timer.Start();
            }
            else
            {
                m_Timer.Stop();
                m_ProgressValue = 0;
            }

            GenerateColorsPallet();
            Invalidate();
        }

        /// <summary>
        /// Sets the circle appearance.
        /// </summary>
        /// <param name="numberSpoke">The number spoke.</param>
        /// <param name="spokeThickness">The spoke thickness.</param>
        /// <param name="innerCircleRadius">The inner circle radius.</param>
        /// <param name="outerCircleRadius">The outer circle radius.</param>
        public void SetCircleAppearance(int numberSpoke, int spokeThickness,
            int innerCircleRadius, int outerCircleRadius)
        {
            NumberSpoke = numberSpoke;
            SpokeThickness = spokeThickness;
            InnerCircleRadius = innerCircleRadius;
            OuterCircleRadius = outerCircleRadius;

            Invalidate();
        } 




    }
}

Answer 1

很抱歉回答我自己的帖子，但经过测试很多项目后，修改没有成功，我终于找到一个几乎完全透明的

https://www.codeproject.com/Articles/27185/WYSIWYG-Progress-Circle-for-NET-Framework-C

那家伙在大约10年前做得非常出色，至少旋转的内部部分被复制并在OnPaint中重新绘制，因此在RichTextBox控件上非常好透明，其他所有项目都失败了：）

唯一的小问题是圆圈痕迹，不要将bmp复制到后面，所以总会有彗星效应，但我可以忍受！比其他解决方案更令人愉快的效果，包括很少的stackoverflow。

万一有人需要！

Answer 2

哇，这看起来非常复杂。我不太了解wpf，但在iOS上我们通常会加载一个具有我们所需的确切属性的图像（这里是透明背景），然后旋转图像以产生旋转效果。

您只需要很少的逻辑就可以使其显示/消失和旋转。对于一个非常基本的微调器，您可以在几秒钟内创建并使用该类。

至少是我想要的路线，而不是编写300行代码来手动处理微调器：p

c＃透明纺车（或gif）只是透明的一半

2 个答案: