实现了观察者模式的用户控件。

在学习 IssueVision 过程中，提到过观察者模式的用户控件(ChartPanel?)，我按自己的设计思路也做了个不伦不类的观察者模式+用户控件，记录下来。

首先，建立一个观察者模式的接口 IObserver.cs

 

using System;
using System.Collections.Generic;
using System.Text;

namespace IssueVision
{
   public interface  IObserver  //接口声明
    {
       void NotifyDataChange(ChartData nChartData); //事件，当数据改变时
    }

    //ChartData 类，表示三类事务，open,work,close
    public class ChartData
    {
        private int n_open;
        private int n_work;
        private int n_close;
        private int n_max;

        public int open
        {
            get
            {
                return n_open;
            }
            set
            {
                n_open = value > 0 ? value : 0;
                n_max = value > n_max ? value : n_max;
            }
        }

        public int work
        {
            get
            {
                return n_work;
            }
            set
            {
                n_work = value > 0 ? value : 0;
                n_max = value > n_max ? value : n_max;
            }
        }

        public int close
        {
            get
            {
                return n_close;
            }
            set
            {
                n_close = value > 0 ? value : 0;
                n_max = value > n_max ? value : n_max;
            }
        }

        public int max
        {
            get
            {
                return n_max;
            }
            set
            {
                n_max = value > 0 ? value : 0;
            }
        }

    }
}

 

接着声明主体 ISubject.cs

using System;
using System.Collections.Generic;
using System.Text;

namespace IssueVision
{
    public interface  ISubject  //声明主体接口
    {
        // 需实现这两个，实现注册和反注册
        void Register(IObserver anObject);
        void UnRegister(IObserver anObject);
    }
}

 

现在新建一个用户控件，放上一个 lbltitle 表示标题，三个 label 分别表示 open , work , close，再放三个 progressbar 表示数量，因为懒得画条形图，所以直接用 progressbar ， 不过，用 progressbar 很难看倒是真的:(。，用户控件叫 ChartPanel.cs，代码如下

 

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Text;
using System.Windows.Forms;

namespace IssueVision.UserControls
{
    public partial class ChartPanel : UserControl , IObserver   //指定 IObserver ，表示实现它
    {
        private string m_title;
        private int n_max;
        private int n_open;
        private int n_working;
        private int n_closed;

        [Description("图表标题")]
        public string Title
        {
            get
            {
                return m_title;
            }
            set
            {
                m_title = value;
                Invalidate();
            }
        }

        [Description("最大数量")]
        public int NMAX
        {
            get
            {
                return n_max;
            }
            set
            {
                n_max = value > 0 ? value : 0;
                Invalidate();
            }
        }

        [Description("打开任务数量")]
        public int NOpen
        {
            get
            {
                return n_open;
            }
            set
            {
                n_open = value > 0 ? value : 0;
                Invalidate();
            }
        }

        [Description("进行的任务数量")]
        public int NWorking
        {
            get
            {
                return n_working;
            }
            set
            {
                n_working = value > 0 ? value : 0;
                Invalidate();
            }
        }

        [Description("关闭的任务数量")]
        public int NClosed
        {

            get
            {
                return n_closed;
            }
            set
            {
                n_closed = value > 0 ? value : 0;
                Invalidate();
            }
        }

        public void NotifyDataChange(ChartData nChartData)  //实现观察者的 NotifyDataChage，表示当接受到数据变更时应用的动作。
        {
            //
            n_max = nChartData.max;
            n_open = nChartData.open;
            n_working = nChartData.work;
            n_closed = nChartData.close;
            Invalidate();
        }

        public ChartPanel()
        {
            InitializeComponent();
        }

        private void ChartPanel_Paint(object sender, PaintEventArgs e)
        {
            this.lbTitle.Text = m_title;
            pbOpen.Minimum = 0;
            pbWorking.Minimum = 0;
            pbClosed.Minimum = 0;

            pbOpen.Maximum = n_max;
            pbWorking.Maximum = n_max;
            pbClosed.Maximum = n_max;

            pbOpen.Value = n_open > n_max ? n_max : n_open;
            pbWorking.Value = n_working > n_max ? n_max : n_working;
            pbClosed.Value = n_closed > n_max ? n_max : n_closed;
        }
    }
}

下面是设计器形成的，ChartPanel的设计代码，一并留下

 

namespace IssueVision.UserControls
{
    partial class ChartPanel
    {
        /**//// <summary> 
        /// 必需的设计器变量。
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /**//// <summary> 
        /// 清理所有正在使用的资源。
        /// </summary>
        /// <param name="disposing">如果应释放托管资源，为 true；否则为 false。</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        组件设计器生成的代码#region 组件设计器生成的代码

        /**//// <summary> 
        /// 设计器支持所需的方法 - 不要
        /// 使用代码编辑器修改此方法的内容。
        /// </summary>
        private void InitializeComponent()
        {
            System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(ChartPanel));
            this.pnlTop = new System.Windows.Forms.Panel();
            this.lbTitle = new System.Windows.Forms.Label();
            this.lblOpen = new System.Windows.Forms.Label();
            this.lblWorking = new System.Windows.Forms.Label();
            this.lblclosed = new System.Windows.Forms.Label();
            this.pbOpen = new System.Windows.Forms.ProgressBar();
            this.pbWorking = new System.Windows.Forms.ProgressBar();
            this.pbClosed = new System.Windows.Forms.ProgressBar();
            this.pnlTop.SuspendLayout();
            this.SuspendLayout();
            // 
            // pnlTop
            // 
            this.pnlTop.BackgroundImage = ((System.Drawing.Image)(resources.GetObject("pnlTop.BackgroundImage")));
            this.pnlTop.Controls.Add(this.lbTitle);
            this.pnlTop.Dock = System.Windows.Forms.DockStyle.Top;
            this.pnlTop.Location = new System.Drawing.Point(0, 0);
            this.pnlTop.Name = "pnlTop";
            this.pnlTop.Size = new System.Drawing.Size(205, 16);
            this.pnlTop.TabIndex = 0;
            // 
            // lbTitle
            // 
            this.lbTitle.AutoSize = true;
            this.lbTitle.BackColor = System.Drawing.Color.Transparent;
            this.lbTitle.Dock = System.Windows.Forms.DockStyle.Fill;
            this.lbTitle.Location = new System.Drawing.Point(0, 0);
            this.lbTitle.Name = "lbTitle";
            this.lbTitle.Size = new System.Drawing.Size(77, 12);
            this.lbTitle.TabIndex = 0;
            this.lbTitle.Text = "标题标题标题";
            this.lbTitle.TextAlign = System.Drawing.ContentAlignment.MiddleCenter;
            // 
            // lblOpen
            // 
            this.lblOpen.AutoSize = true;
            this.lblOpen.Location = new System.Drawing.Point(9, 39);
            this.lblOpen.Name = "lblOpen";
            this.lblOpen.Size = new System.Drawing.Size(29, 12);
            this.lblOpen.TabIndex = 1;
            this.lblOpen.Text = "打开";
            // 
            // lblWorking
            // 
            this.lblWorking.AutoSize = true;
            this.lblWorking.Location = new System.Drawing.Point(9, 77);
            this.lblWorking.Name = "lblWorking";
            this.lblWorking.Size = new System.Drawing.Size(29, 12);
            this.lblWorking.TabIndex = 2;
            this.lblWorking.Text = "进行";
            // 
            // lblclosed
            // 
            this.lblclosed.AutoSize = true;
            this.lblclosed.Location = new System.Drawing.Point(9, 112);
            this.lblclosed.Name = "lblclosed";
            this.lblclosed.Size = new System.Drawing.Size(29, 12);
            this.lblclosed.TabIndex = 3;
            this.lblclosed.Text = "关闭";
            // 
            // pbOpen
            // 
            this.pbOpen.Location = new System.Drawing.Point(44, 28);
            this.pbOpen.Name = "pbOpen";
            this.pbOpen.Size = new System.Drawing.Size(155, 23);
            this.pbOpen.Step = 1;
            this.pbOpen.TabIndex = 4;
            // 
            // pbWorking
            // 
            this.pbWorking.Location = new System.Drawing.Point(44, 66);
            this.pbWorking.Name = "pbWorking";
            this.pbWorking.Size = new System.Drawing.Size(155, 23);
            this.pbWorking.TabIndex = 5;
            // 
            // pbClosed
            // 
            this.pbClosed.Location = new System.Drawing.Point(45, 101);
            this.pbClosed.Name = "pbClosed";
            this.pbClosed.Size = new System.Drawing.Size(154, 23);
            this.pbClosed.TabIndex = 6;
            // 
            // ChartPanel
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.Controls.Add(this.pbClosed);
            this.Controls.Add(this.pbWorking);
            this.Controls.Add(this.pbOpen);
            this.Controls.Add(this.lblclosed);
            this.Controls.Add(this.lblWorking);
            this.Controls.Add(this.lblOpen);
            this.Controls.Add(this.pnlTop);
            this.Name = "ChartPanel";
            this.Size = new System.Drawing.Size(205, 135);
            this.Paint += new System.Windows.Forms.PaintEventHandler(this.ChartPanel_Paint);
            this.pnlTop.ResumeLayout(false);
            this.pnlTop.PerformLayout();
            this.ResumeLayout(false);
            this.PerformLayout();

        }

        #endregion

        private System.Windows.Forms.Panel pnlTop;
        private System.Windows.Forms.Label lbTitle;
        private System.Windows.Forms.Label lblOpen;
        private System.Windows.Forms.Label lblWorking;
        private System.Windows.Forms.Label lblclosed;
        private System.Windows.Forms.ProgressBar pbOpen;
        private System.Windows.Forms.ProgressBar pbWorking;
        private System.Windows.Forms.ProgressBar pbClosed;
    }
}

新建一个窗体，放上刚才的用户控件 chartpanel1,放置 textbox2,3,4  ，放一个按钮。

 

    public class SubjectImpl:ISubject //被观察者的实现
    {
        protected Hashtable _observerContaind = new Hashtable();

        public void Register(IObserver anObserver)
        {
            _observerContaind.Add(anObserver,anObserver);
        }

        public void UnRegister(IObserver anObserver)
        {
            _observerContaind.Remove(anObserver);
        }

        public void NotifyObservers(ChartData n_data)
        {
            foreach (IObserver anObserver in _observerContaind.Keys)
            {
                anObserver.NotifyDataChange(n_data);
            }
        }
    }

    public class MyData :SubjectImpl
    {
        private ChartData _cd = new ChartData();

        public ChartData CD
        {
            get
            {
                return _cd;
            }
            set
            {
                _cd = value;
                base.NotifyObservers(_cd);
            }
        }

    }

 

 

        private void button1_Click(object sender, EventArgs e)
        {
            ChartData mycd=new ChartData();
            mycd.open=Convert.ToInt16(textBox2.Text);
            mycd.work=Convert.ToInt16(textBox3.Text);
            mycd.close=Convert.ToInt16(textBox4.Text);
            MyData md = new MyData();
            md.Register(chartPanel1);
            md.CD = mycd;

        }

 

 

呼，终于完了，点此 button 后，chartpanel 将会更改，不过，这么做会不会太麻烦了？

转载于:https://www.cnblogs.com/qufo/archive/2007/08/14/855595.html