C#根據句柄改變窗體控件值

需求是這樣，有個程序界面我們需要通過自己的程序持續輸入數據，界面如圖。

可以獲得控件的句柄而用鈎子寫入值。這里需要用到spy++工具。在VS的工具下有個spy++工具，打開如下圖

通過這個工具可以獲得窗體的句柄，當然這里獲得的句柄只能用於測試，因為.net開發的程序窗體每次打開句柄都會變，都需要重新獲得。這個工具的用處在於找一個控件的前一句柄控件和后一句柄控件。

一、引用

//尋找目標進程窗口       
[DllImport("USER32.DLL")]
public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
[DllImport("USER32.DLL", EntryPoint = "FindWindowEx", SetLastError = true)]
public static extern IntPtr FindWindowEx(IntPtr hwndParent, uint hwndChildAfter,string lpszClass, string lpszWindow);
//設置進程窗口到最前       
[DllImport("USER32.DLL")]
public static extern bool SetForegroundWindow(IntPtr hWnd);
//模擬鍵盤事件         
[DllImport("USER32.DLL")]
public static extern void keybd_event(Byte bVk, Byte bScan, Int32 dwFlags, Int32 dwExtraInfo);
public delegate bool CallBack(IntPtr hwnd, int lParam);
[DllImport("USER32.DLL")]
public static extern int EnumChildWindows(IntPtr hWndParent, CallBack lpfn, int lParam);
//給CheckBox發送信息
[DllImport("USER32.DLL", EntryPoint = "SendMessage", SetLastError = true, CharSet = CharSet.Auto)]
public static extern int SendMessage(IntPtr hwnd, UInt32 wMsg, int wParam, int lParam);
//給Text發送信息
[DllImport("USER32.DLL", EntryPoint = "SendMessage")]
private static extern int SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, string lParam);
[DllImport("USER32.DLL")]
public static extern IntPtr GetWindow(IntPtr hWnd, int wCmd);

二、方法

公共方法

/// <summary>
/// 查找窗體上控件句柄
/// </summary>
/// <param name="hwnd">父窗體句柄</param>
/// <param name="lpszWindow">控件標題(Text)</param>
/// <param name="bChild">設定是否在子窗體中查找</param>
/// <returns>控件句柄，沒找到返回IntPtr.Zero</returns>
private static IntPtr FindWindowEx(IntPtr hwnd, string lpszWindow, bool bChild)
{
    IntPtr iResult = IntPtr.Zero;
    // 首先在父窗體上查找控件
    iResult = FindWindowEx(hwnd, 0, null, lpszWindow);
    // 如果找到直接返回控件句柄
    if (iResult != IntPtr.Zero) return iResult;
    // 如果設定了不在子窗體中查找
    if (!bChild) return iResult;
    // 枚舉子窗體，查找控件句柄
    int i = EnumChildWindows(
    hwnd,
    (h, l) =>
    {
        IntPtr f1 = FindWindowEx(h, 0, null, lpszWindow);
        if (f1 == IntPtr.Zero)
            return true;
        else
        {
            iResult = f1;
            return false;
        }
    },
    0);
    // 返回查找結果
    return iResult;
}

/// <summary>
/// 輸入回車
/// </summary>
private static void PrintEnter()
{
    keybd_event(Convert.ToByte(13), 0, 0, 0);
    keybd_event(Convert.ToByte(13), 0, 2, 0);
}

獲得窗體句柄

IntPtr wcHandle = FindWindow(null, "窗體名稱");
if (wcHandle != IntPtr.Zero)
{
    //設置游戲窗口到最前
    SetForegroundWindow(wcHandle);
}

獲得有Title的控件句柄

uint BM_GETCHECK = 0xF0;
uint BST_CHECKED = 0xF1;

IntPtr weightIntPtr = FindWindowEx(wcHandle, "輸入重量[&H]", true);
if (weightIntPtr != IntPtr.Zero)
{
    //獲得Checkbox值
    int i = SendMessage(weightIntPtr, BM_GETCHECK, 0, 0);
    //更改CheckBox值
    SendMessage(weightIntPtr, BST_CHECKED, 1, 0);
}

獲得沒Title的控件句柄

public enum WindowSearch
{
    GW_HWNDFIRST = 0, //同級別第一個
    GW_HWNDLAST = 1, //同級別最后一個
    GW_HWNDNEXT = 2, //同級別下一個
    GW_HWNDPREV = 3, //同級別上一個
    GW_OWNER = 4, //屬主窗口
    GW_CHILD = 5 //子窗口}獲取與指定窗口具有指定關系的窗口的句柄 
}
IntPtr waybill = GetWindow(waybillIntPtr, (int)WindowSearch.GW_HWNDNEXT);
SendMessage(waybill, WM_SETTEXT, IntPtr.Zero, waybillValue);

這里完成了我們的需求，改變了窗體中選擇框和Text文本框的值。