WPF 開發的實用小工具（附原始碼）持續更新（七）根據應用首個字的首字母按鍵定位

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 在使用程序中當應用太多很難快速的找到并定位到自己所需要使用的應用，所以此次做了更新方便快速查找應用，

【update】
1、輸入應用首字的首字母定位，

鍵盤按下 KeyDown 

定義ScrollViewer 所需要滾動值 double offset = 0.0;，

定義 bool isFind = false; 如果為 True 找到就不查找控制元件，

1、通過FindChild查找ScrollViewer方便最后定位使用，

ScrollViewer scrollViewer = ControlsHelper.FindChild<ScrollViewer>(this.AppSwitchList, "PART_ScrollViewer");

2、通過FindVisualChildren查找我所定義DataTemplate下的Border，

var elementList = ControlsHelper.FindVisualChildren<Border>(this.AppSwitchList).ToList();

3、回圈 elementList 集合，判斷 Tag 不等于 null 時對 offset += element.ActualHeight ，并且相等于按下鍵盤的Key值，

if (element.Tag != null && element.Tag.ToString().Equals(_key))
4、定位到找到的第一個與Key相等的，

scrollViewer.ScrollToVerticalOffset(offset);

var _key = Win32Api.GetCharFromKey(e.Key).ToString().ToUpper();
            if (string.IsNullOrWhiteSpace(_key))
                return;
            double offset = 0.0;
            ScrollViewer scrollViewer = ControlsHelper.FindChild<ScrollViewer>(this.AppSwitchList, "PART_ScrollViewer");
            var elementList = ControlsHelper.FindVisualChildren<Border>(this.AppSwitchList).ToList();
            bool isFind = false;
            for (int i = 0; i < elementList.Count; i++)
            {
                var element = elementList[i];
                if (isFind) break;
                if (element.Tag != null)
                {
                    offset += element.ActualHeight;
                    if (element.Tag.ToString().Equals(_key))
                    {
                        offset -= element.ActualHeight;
                        scrollViewer.ScrollToVerticalOffset(offset);
                        isFind = true;
                    }
                }

            }
            this.KeyDownText.Text = _key;
            this.KeyDownPanel.Visibility = Visibility.Visible;

獲取按鍵轉譯

public enum MapType : uint
        {
            MAPVK_VK_TO_VSC = 0x0,
            MAPVK_VSC_TO_VK = 0x1,
            MAPVK_VK_TO_CHAR = 0x2,
            MAPVK_VSC_TO_VK_EX = 0x3,
        }

        [DllImport("user32.dll")]
        public static extern int ToUnicode(
            uint wVirtKey,
            uint wScanCode,
            byte[] lpKeyState,
            [Out, MarshalAs(UnmanagedType.LPWStr, SizeParamIndex = 4)]
            StringBuilder pwszBuff,
            int cchBuff,
            uint wFlags);

        [DllImport("user32.dll")]
        public static extern bool GetKeyboardState(byte[] lpKeyState);

        [DllImport("user32.dll")]
        public static extern uint MapVirtualKey(uint uCode, MapType uMapType);

        public static char GetCharFromKey(Key key)
        {
            char ch = ' ';

            int virtualKey = KeyInterop.VirtualKeyFromKey(key);
            byte[] keyboardState = new byte[256];
            GetKeyboardState(keyboardState);

            uint scanCode = MapVirtualKey((uint)virtualKey, MapType.MAPVK_VK_TO_VSC);
            StringBuilder stringBuilder = new StringBuilder(2);

            int result = ToUnicode((uint)virtualKey, scanCode, keyboardState, stringBuilder, stringBuilder.Capacity, 0);
            switch (result)
            {
                case -1:
                    break;
                case 0:
                    break;
                case 1:
                    {
                        ch = stringBuilder[0];
                        break;
                    }
                default:
                    {
                        ch = stringBuilder[0];
                        break;
                    }
            }
            return ch;
        }

 抬起后隱藏

  Thread.Sleep(300);
            this.KeyDownPanel.Visibility = Visibility.Collapsed;

 效果圖

 原始碼下載地址

 gitee

下載解壓后體驗

標籤：.NET技术

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