Winform等待窗口的实现（附源代码）

在开发Winform程序的时候，经常会用到等待窗口（如网络通讯、数据库连接等需要一定时间来执行的操作），这样可以给用户提供更好的体验。

         等待窗口的主要功能是一边执行需要等待的操作，一边显示一个等待界面。当执行完毕时等待界面消失。用户可以提前取消操作，还可以设置操作的最大等待时间，若超过指定时间仍没完成操作可结束当前操作。等待窗口的操作处理内容可用λ表达式，在后面的应用实例中可看到使用方法。

         实现界面如下图：

 

         等待界面主要包含的部分：

• 等待图片；
• 等待消息文字("正在处理数据，请稍后...")：可自定义；
• 计时器：可设置不显示；
• 取消返回按钮：可设置不显示；
• 另外等待窗口显示和关闭的时候都有渐变的一个简单特效，等待窗口的颜色是在一定范围内随即的。

等待窗口实现代码：

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

namespace WinForm_Test
{
    public partial class frmWaitingBox : Form
    {
        #region Properties
        private int _MaxWaitTime;
        private int _WaitTime;
        private bool _CancelEnable;
        private IAsyncResult _AsyncResult;
        private EventHandler<EventArgs> _Method;
        private bool _IsShown = true;
        private readonly int _EffectCount = 10;
        private readonly int _EffectTime = 500;
        /// <summary>
        /// 控制界面显示的特性
        /// </summary>
        private Timer _Timer;
        public string Message { get; private set; }
        public int TimeSpan { get; set; }
        public bool FormEffectEnable { get; set; }
        #endregion

        #region frmWaitingBox
        public frmWaitingBox(EventHandler<EventArgs> method,int maxWaitTime,string waitMessage,bool cancelEnable,bool timerVisable)
        {
            maxWaitTime *= 1000;
            Initialize(method, maxWaitTime,waitMessage, cancelEnable, timerVisable);
        }
        public frmWaitingBox(EventHandler<EventArgs> method)
        {
            int maxWaitTime=60*1000;
            string waitMessage = "正在处理数据，请稍后...";
            bool cancelEnable=true;
            bool timerVisable=true;
            Initialize(method, maxWaitTime,waitMessage, cancelEnable, timerVisable);
        }
        public frmWaitingBox(EventHandler<EventArgs> method, string waitMessage)
        {
            int maxWaitTime = 60 * 1000;
            bool cancelEnable = true;
            bool timerVisable = true;
            Initialize(method, maxWaitTime, waitMessage, cancelEnable, timerVisable);
        }
        public frmWaitingBox(EventHandler<EventArgs> method, bool cancelEnable, bool timerVisable)
        {
            int maxWaitTime = 60*1000;
            string waitMessage = "正在处理数据，请稍后...";
            Initialize(method, maxWaitTime,waitMessage, cancelEnable, timerVisable);
        }
        #endregion

        #region Initialize
        private void Initialize(EventHandler<EventArgs> method, int maxWaitTime,string waitMessage,bool cancelEnable, bool timerVisable)
        {
            InitializeComponent();
            //initialize form
            this.FormBorderStyle = FormBorderStyle.None;
            this.StartPosition = FormStartPosition.CenterParent;
            this.ShowInTaskbar = false;
            Color[] c = GetRandColor();
            this.panel1.BackColor = c[0];
            this.BackColor = c[1];
            this.labMessage.Text = waitMessage;
            _Timer = new Timer();
            _Timer.Interval = _EffectTime/_EffectCount;
            _Timer.Tick += _Timer_Tick;
            this.Opacity = 0;
            FormEffectEnable = true;
            //para
            TimeSpan = 500;
            Message = string.Empty;
            _CancelEnable = cancelEnable;
            _MaxWaitTime = maxWaitTime;
            _WaitTime = 0;
            _Method = method;
            this.pictureBoxCancel.Visible = _CancelEnable;
            this.labTimer.Visible = timerVisable;
            this.timer1.Interval = TimeSpan;
            this.timer1.Start();
        }
        #endregion

        #region Color
        private Color[] GetRandColor()
        {
            int rMax = 248;
            int rMin = 204;
            int gMax = 250;
            int gMin = 215;
            int bMax = 250;
            int bMin = 240;
            Random r = new Random(DateTime.Now.Millisecond);
            int r1 = r.Next(rMin, rMax);
            int r2 = r1 + 5;
            int g1 = r.Next(gMin, gMax);
            int g2 = g1 + 5;
            int b1 = r.Next(bMin, bMax);
            int b2 = b1 + 5;
            Color c1 = Color.FromArgb(r1, g1, b1);
            Color c2 = Color.FromArgb(r2, g2, b2);
            Color[] c = { c1, c2 };
            return c;
        }
        #endregion

        #region Events
        private void btnCancel_Click(object sender, EventArgs e)
        {
            this.Message = "您结束了当前操作！";
            this.Close();
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            _WaitTime += TimeSpan;
            this.labTimer.Text = string.Format("{0}秒", _WaitTime / 1000);
            if (!this._AsyncResult.IsCompleted)
            {
                if (_WaitTime > _MaxWaitTime)
                {
                    Message = string.Format("处理数据超时{0}秒，结束当前操作！", _MaxWaitTime / 1000);
                    this.Close();
                }
            }
            else
            {
                this.Message = string.Empty;
                this.Close();
            }
            
        }

        private void frmWaitingBox_Shown(object sender, EventArgs e)
        {
            _AsyncResult = _Method.BeginInvoke(null, null, null, null);
            //Effect
            if (FormEffectEnable)
            {
                _Timer.Start();
            }
            else
                this.Opacity = 1;
        }
        private void frmWaitingBox_FormClosing(object sender, FormClosingEventArgs e)
        {
            if (FormEffectEnable)
            {
                if(this.Opacity>=1)
                    e.Cancel = true;
                _Timer.Start();
            }
        }
        private void _Timer_Tick(object sender, EventArgs e)
        {
            if (_IsShown)
            {
                if (this.Opacity >= 1)
                {
                    _Timer.Stop();
                    _IsShown = false;
                }
                this.Opacity += 1.00 / _EffectCount;
            }
            else
            {
                if (this.Opacity <= 0)
                {
                    _Timer.Stop();
                    _IsShown = true;
                    this.Close();
                }
                this.Opacity -= 1.00 / _EffectCount;
            }
        }
        #endregion

        
    }
}

应用实例代码：

           string res;
            DataTable dt=null;
            frmWaitingBox f = new frmWaitingBox((obj,args)=>
                {
                    Thread.Sleep(5000);
                    string sql = "SELECT * FROM [test].[dbo].[studentInfo]";
                    SQLHelper sqlHelper=new SQLHelper();
                    dt = sqlHelper.ExecuteSqlStr(sql,out res);
                });
            f.ShowDialog(this);

            dataGridView1.DataSource = dt;

源码下载：下载地址——（https://files.cnblogs.com/anding/WinForm_Test1.rar）