WindowsForm实现警告消息框

警告消息框主要是用来向用户户展示诸如警告、异常、完成和提示消息。一般实现的效果就是从系统窗口右下角弹出，然后加上些简单的显示和消失的动画。

创建警告框窗口

首先我们创建一个警告框窗口(Form)，将窗口设置为无边框(FormBoderStyle=None)，添加上图片和内容显示控件

创建好警告框后，我们先让他能够从窗口右下角显示出来,

    public partial class AlertMessageForm : Form
    {
        public AlertMessageForm()
        {
            InitializeComponent();
        }

        private int x, y;

        public void Show(string message)
        {
            this.StartPosition = FormStartPosition.Manual;
            this.x = Screen.PrimaryScreen.WorkingArea.Width - this.Width;
            this.y = Screen.PrimaryScreen.WorkingArea.Height - this.Height;
            this.Location = new Point(x, y);
            labelContent.Text = message;
            this.Show();
        }
    }

警告框显示和关闭动画

添加一个计时器，通过时钟控制窗口背景渐入和淡出

    // 警告框的行为（显示，停留，退出）
    public enum AlertFormAction
    {
        Start,
        Wait,
        Close
    }

    public partial class AlertMessageForm : Form
    {
        public AlertMessageForm()
        {
            InitializeComponent();
        }

        private int x, y;
        private AlertFormAction action;

        private void timer1_Tick(object sender, EventArgs e)
        {
            switch (action)
            {
                case AlertFormAction.Start:
                    timer1.Interval = 50;//警告显示的时间
                    this.Opacity += 0.1;
                    if (this.Opacity == 1.0)
                    {
                        action = AlertFormAction.Wait;
                    }
                    break;
                case AlertFormAction.Wait:
                    timer1.Interval = 3000;//警告框停留时间
                    action = AlertFormAction.Close;
                    break;
                case AlertFormAction.Close:
                    timer1.Interval = 50;//警告退出的时间
                    this.Opacity -= 0.1;
                    if (this.Opacity == 0.0)
                    {
                        this.Close();
                    }
                    break;
                default:
                    break;
            }
        }

        public void Show(string message)
        {
            //设置窗口启始位置
            this.StartPosition = FormStartPosition.Manual;
            this.x = Screen.PrimaryScreen.WorkingArea.Width - this.Width;
            this.y = Screen.PrimaryScreen.WorkingArea.Height - this.Height;
            this.Location = new Point(x, y);

            labelContent.Text = message;
            this.Opacity = 0.0;

            this.Show();

            action = AlertFormAction.Start;
            //启动时钟
            timer1.Start();
        }
    }

处理多种不同类型的警告框

添加AlertType枚举，让警告框显示不同类型的消息，根据消息类型变换不同的消息主题颜色,并未Show方法添加警告框类型参数

   public enum AlertType
   {
       Info,
       Success,
       Warning,
       Error
   }

  // 设置警告框主题
  private void SetAlertTheme(AlertType type)
  {
      switch (type)
      {
          case AlertType.Info:
              this.pictureBox1.Image = Properties.Resources.info;
              this.BackColor = Color.RoyalBlue;
              break;
          case AlertType.Success:
              this.pictureBox1.Image = Properties.Resources.success;
              this.BackColor = Color.SeaGreen;
              break;
          case AlertType.Warning:
              this.pictureBox1.Image = Properties.Resources.warning;
              this.BackColor = Color.DarkOrange;
              break;
          case AlertType.Error:
              this.pictureBox1.Image = Properties.Resources.error;
              this.BackColor = Color.DarkRed;
              break;
          default:
              break;
      }
  }

  // 显示警告框
  public void Show(string message, AlertType type){
    // ...
    SetAlertTheme(type);
  }
      

处理多个警告框重叠问题

当然，完成上面的处理是不够的，当有多个消息的时候，消息框会重叠在一起；多个消息时，需要将消息窗口按一定的规则排列，这里我们设置每个消息窗口间隔一定的距离

        public void Show(string message, AlertType type)
        {
            // 设置窗口启始位置
            this.StartPosition = FormStartPosition.Manual;

            // 设置程序每个打开的消息窗口的位置，超过10个就不做处理，这个可以根据自己的需求设定
            string fname;
            for (int i = 1; i < 10; i++)
            {
                fname = "alert" + i.ToString();
                AlertMessageForm alert = (AlertMessageForm)Application.OpenForms[fname];
                if (alert == null)
                {
                    this.Name = fname;
                    this.x = Screen.PrimaryScreen.WorkingArea.Width - this.Width;
                    this.y = Screen.PrimaryScreen.WorkingArea.Height - this.Height * i - 5 * i;
                    this.Location = new Point(x, y);
                    break;
                }
            }

            labelContent.Text = message;
            this.Opacity = 0.0;
            SetAlertTheme(type);
            this.Show();

            action = AlertFormAction.Start;
            //启动时钟
            timer1.Start();
        }

鼠标悬停警告框处理

想要警告框停留的时间长一些，一中方式是直接设置警告框停留的时间长一些，另一种方式是通过判断鼠标在警告框窗口是否悬停，所以可以通过鼠标的悬停和离开事件进行处理

        private void AlertMessageForm_MouseMove(object sender, MouseEventArgs e)
        {
            this.Opacity = 1.0;
            timer1.Interval = int.MaxValue;//警告框停留时间
            action = AlertFormAction.Close;
        }

        private void AlertMessageForm_MouseLeave(object sender, EventArgs e)
        {
            this.Opacity = 1.0;
            timer1.Interval = 3000;//警告框停留时间
            action = AlertFormAction.Close;
        }

警告框的完整代码

    public enum AlertType
    {
        Info,
        Success,
        Warning,
        Error
    }

    public enum AlertFormAction
    {
        Start,
        Wait,
        Close
    }

    public partial class AlertMessageForm : Form
    {
        public AlertMessageForm()
        {
            InitializeComponent();
        }

        private int x, y;
        private AlertFormAction action;

        private void timer1_Tick(object sender, EventArgs e)
        {
            switch (action)
            {
                case AlertFormAction.Start:
                    timer1.Interval = 50;//警告显示的时间
                    this.Opacity += 0.1;
                    if (this.Opacity == 1.0)
                    {
                        action = AlertFormAction.Wait;
                    }
                    break;
                case AlertFormAction.Wait:
                    timer1.Interval = 3000;//警告框停留时间
                    action = AlertFormAction.Close;
                    break;
                case AlertFormAction.Close:
                    timer1.Interval = 50;//警告关闭的时间
                    this.Opacity -= 0.1;
                    if (this.Opacity == 0.0)
                    {
                        this.Close();
                    }
                    break;
                default:
                    break;
            }
        }

        public void Show(string message, AlertType type)
        {
            // 设置窗口启始位置
            this.StartPosition = FormStartPosition.Manual;

            // 设置程序每个打开的消息窗口的位置，超过10个就不做处理，这个可以根据自己的需求设定
            string fname;
            for (int i = 1; i < 10; i++)
            {
                fname = "alert" + i.ToString();
                AlertMessageForm alert = (AlertMessageForm)Application.OpenForms[fname];
                if (alert == null)
                {
                    this.Name = fname;
                    this.x = Screen.PrimaryScreen.WorkingArea.Width - this.Width;
                    this.y = Screen.PrimaryScreen.WorkingArea.Height - this.Height * i - 5 * i;
                    this.Location = new Point(x, y);
                    break;
                }
            }

            labelContent.Text = message;
            this.Opacity = 0.0;
            SetAlertTheme(type);
            this.Show();

            action = AlertFormAction.Start;
            //启动时钟
            timer1.Start();
        }

        private void AlertMessageForm_MouseMove(object sender, MouseEventArgs e)
        {
            this.Opacity = 1.0;
            timer1.Interval = int.MaxValue;//警告框停留时间
            action = AlertFormAction.Close;
        }

        private void AlertMessageForm_MouseLeave(object sender, EventArgs e)
        {
            this.Opacity = 1.0;
            timer1.Interval = 3000;//警告框停留时间
            action = AlertFormAction.Close;
        }

        private void buttonClose_Click(object sender, EventArgs e)
        {
            // 注销鼠标事件
            this.MouseLeave-= new System.EventHandler(this.AlertMessageForm_MouseLeave);
            this.MouseMove -= new System.Windows.Forms.MouseEventHandler(this.AlertMessageForm_MouseMove);

            timer1.Interval = 50;//警告关闭的时间
            this.Opacity -= 0.1;
            if (this.Opacity == 0.0)
            {
                this.Close();
            }
        }

        // 设置警告框主题
        private void SetAlertTheme(AlertType type)
        {
            switch (type)
            {
                case AlertType.Info:
                    this.pictureBox1.Image = Properties.Resources.info;
                    this.BackColor = Color.RoyalBlue;
                    break;
                case AlertType.Success:
                    this.pictureBox1.Image = Properties.Resources.success;
                    this.BackColor = Color.SeaGreen;
                    break;
                case AlertType.Warning:
                    this.pictureBox1.Image = Properties.Resources.warning;
                    this.BackColor = Color.DarkOrange;
                    break;
                case AlertType.Error:
                    this.pictureBox1.Image = Properties.Resources.error;
                    this.BackColor = Color.DarkRed;
                    break;
                default:
                    break;
            }
        }
    }