WPF 利用子線程彈出子窗體的研究

　　一般來說子線程都是用來處理數據的，主窗體用來實現展現，但是有些時候我們希望子窗體實現等待效果，遮擋主窗體並使主窗體邏輯正常進行，這個業務需求雖然不多，但是正好我們用到了，於是我打算把研究成果寫在這了。稍后我會上傳我的代碼，包含測試程序以及之前兩邊博文談到的控件，這里我還實現了一個類似雷達掃描的等待窗體，大家可以稍后查看。

　　實際上這里只有兩個難點需要處理，一個就是如何讓子窗體遮擋主窗體並位於主窗體中間，另一個就是委托及跨線程訪問UI界面。為了方便調用，我在這里寫了一個靜態的子線程窗體管理類DialogWindowsManager。

1.遮擋主窗體

　　大家都知道，showDialog方法就是最好的遮擋效果，但是由於它是線程阻塞的，因此每當我們想到這里的時候會有一個誤區，認為調用showDialog一定會阻塞前台界面，其實這里的阻塞只是阻塞調用方法所在的線程，並不是一定會阻塞主線程，因此在子線程中調用showDialog方法即可達到效果。實際測試時發現遮擋效果確實有了，可惜每次showDialog的時候窗體會滿屏幕亂飛，好吧，最好的方法當然是設置onwer，不過我一直沒嘗試成功，因為主窗體與子窗體一直處於兩個線程中，最后我通過一個算法將位置計算出來之后賦值給了子窗體。代碼如下：

/// <summary>
        /// 打開等待窗體線程
        /// </summary>
        public static void ShowWaitingForm(Window onwer) {
            double[] d = new double[2];
            d[0] = onwer.Top + onwer.Height / 2 - 50;
            d[1] = onwer.Left + onwer.Width / 2 - 50;
            if (WaitingFormThread == null)
            {
                WaitingFormThread = new Thread(new ParameterizedThreadStart(showWaitingForm));
                WaitingFormThread.SetApartmentState(ApartmentState.STA);
                WaitingFormThread.Start(d);
            }
            else {
                CloseWaitingForm();
                ShowWaitingForm(onwer);
            }
        }

2.跨線程訪問

　　這里不得不說WPF還是很給力的，因為它提供了Dispatcher來獲取當前要更新的線程，這里網上資料很多，我就不多做解釋了，直接上代碼：

/// <summary>
        /// 設置進度條百分比
        /// </summary>
        /// <param name="d">百分比</param>
        public static void setProgrssFormPercent(double d) {
            if (cf != null) {
                cf.Dispatcher.BeginInvoke(new Action(() => { if (cf != null) { cf.setPercent(d); } }));
                Thread.Sleep(50);
            }
        }

3.注意事項

　　子線程也是UI線程，因此線程一定要設置為ApartmentState.STA狀態。

完成的線程管理代碼如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Windows;

namespace MyUserControlLibrary
{
    public static class DialogWindowsManager
    {
        #region 屬性

        /// <summary>
        /// 等待窗體處理線程
        /// </summary>
        static Thread WaitingFormThread;
        /// <summary>
        /// 進度條進程
        /// </summary>
        static Thread CircleProgressFormThread;

        /// <summary>
        /// 等待進度條進程
        /// </summary>
        static Thread WaitingAndProgressFormThread;

        /// <summary>
        /// 進度條窗體
        /// </summary>
        static CircleProgressForm cf;
        /// <summary>
        /// 等待進度條
        /// </summary>
        static WaitingAndProgressForm wpf;
        #endregion

        #region 私有方法

        /// <summary>
        /// 打開等待窗體方法
        /// </summary>
        private static void showWaitingForm(object o)
        {
            double[] d = (double[])o;
            WaitingForm wf = new WaitingForm();
            wf.WindowStartupLocation = WindowStartupLocation.Manual;
            wf.Top = d[0];
            wf.Left = d[1];
            wf.ShowDialog();
        }

        /// <summary>
        /// 打開進度條窗體方法
        /// </summary>
        /// <param name="o">顯示位置集合 double[] 0-Top 1-Left</param>
        private static void showCircleProgressForm(object o)
        {
            double[] d = (double[])o;
            cf = new CircleProgressForm();
            cf.WindowStartupLocation = WindowStartupLocation.Manual;
            cf.Top = d[0];
            cf.Left = d[1];
            cf.ShowDialog();
        }

        /// <summary>
        /// 打開進度條窗體方法
        /// </summary>
        /// <param name="o">顯示位置集合 double[] 0-Top 1-Left</param>
        private static void showWaitingAndProgressForm(object o)
        {
            object[] m = (object[])o;
            double[] d = (double[])m[0];
            wpf = new WaitingAndProgressForm();
            wpf.MainControl.ShowType = (WaitAndProgressType)m[1];
            wpf.WindowStartupLocation = WindowStartupLocation.Manual;
            wpf.Top = d[0];
            wpf.Left = d[1];
            wpf.ShowDialog();
        }

        #endregion

        #region 公有方法

        /// <summary>
        /// 打開等待窗體線程
        /// </summary>
        public static void ShowWaitingForm(Window onwer) {
            double[] d = new double[2];
            d[0] = onwer.Top + onwer.Height / 2 - 50;
            d[1] = onwer.Left + onwer.Width / 2 - 50;
            if (WaitingFormThread == null)
            {
                WaitingFormThread = new Thread(new ParameterizedThreadStart(showWaitingForm));
                WaitingFormThread.SetApartmentState(ApartmentState.STA);
                WaitingFormThread.Start(d);
            }
            else {
                CloseWaitingForm();
                ShowWaitingForm(onwer);
            }
        }

        /// <summary>
        /// 關閉等待窗體線程
        /// </summary>
        public static void CloseWaitingForm()
        {
            WaitingFormThread.Abort();
            WaitingFormThread.Join();
            WaitingFormThread.DisableComObjectEagerCleanup();
            WaitingFormThread = null;
        }

        /// <summary>
        /// 打開進度條窗體線程
        /// </summary>
        public static void ShowCircleProgressForm(Window onwer)
        {
            double[] d = new double[2];
            d[0] = onwer.Top + onwer.Height / 2 - 50;
            d[1] = onwer.Left + onwer.Width / 2 - 50;
            if (CircleProgressFormThread == null)
            {
                CircleProgressFormThread = new Thread(new ParameterizedThreadStart(showCircleProgressForm));
                CircleProgressFormThread.SetApartmentState(ApartmentState.STA);
                CircleProgressFormThread.Start(d);
                Thread.Sleep(100);
            }
            else
            {
                CloseCircleProgressForm();
                ShowCircleProgressForm(onwer);
            }
        }

        /// <summary>
        /// 設置進度條百分比
        /// </summary>
        /// <param name="d">百分比</param>
        public static void setProgrssFormPercent(double d) {
            if (cf != null) {
                cf.Dispatcher.BeginInvoke(new Action(() => { if (cf != null) { cf.setPercent(d); } }));
                Thread.Sleep(50);
            }
        }

        /// <summary>
        /// 關閉進度條窗體線程
        /// </summary>
        public static void CloseCircleProgressForm()
        {
            CircleProgressFormThread.Abort();
            CircleProgressFormThread.Join();
            CircleProgressFormThread.DisableComObjectEagerCleanup();
            CircleProgressFormThread = null;
            cf = null;
        }

        /// <summary>
        /// 打開等待進度條窗體線程
        /// </summary>
        public static void ShowWaitingAndProgressForm(Window onwer,WaitAndProgressType t)
        {
            object[] o = new object[2];
            double[] d = new double[2];
            d[0] = onwer.Top + onwer.Height / 2 - 50;
            d[1] = onwer.Left + onwer.Width / 2 - 50;
            o[0] = d;
            o[1] = t;
            if (WaitingAndProgressFormThread == null)
            {
                WaitingAndProgressFormThread = new Thread(new ParameterizedThreadStart(showWaitingAndProgressForm));
                WaitingAndProgressFormThread.SetApartmentState(ApartmentState.STA);
                WaitingAndProgressFormThread.Start(o);
                Thread.Sleep(100);
            }
            else
            {
                CloseWaitingAndProgressForm();
                ShowWaitingAndProgressForm(onwer,t);
            }
        }

        /// <summary>
        /// 設置進度條百分比
        /// </summary>
        /// <param name="d">百分比</param>
        public static void setWaitingAndProgressFormPercent(double d)
        {
            if (wpf != null)
            {
                wpf.Dispatcher.BeginInvoke(new Action(() => { if (wpf != null) { wpf.setPercent(d); } }));
                Thread.Sleep(50);
            }
        }

        /// <summary>
        /// 關閉等待進度條窗體線程
        /// </summary>
        public static void CloseWaitingAndProgressForm()
        {
            WaitingAndProgressFormThread.Abort();
            WaitingAndProgressFormThread.Join();
            WaitingAndProgressFormThread.DisableComObjectEagerCleanup();
            WaitingAndProgressFormThread = null;
            wpf = null;
        }

        #endregion
    }
}

整個解決方案我會上傳的！！

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本文系本人原創，源代碼及文章引用轉載請注明出處！！謝謝！

源碼下載地址：http://files.cnblogs.com/files/lgmbk/UserControlTest.zip