Toggle Enhance pointer precision

We are basically creating a control panel applet. We need to toggle "Enhance pointer precision" in Mouse Properties. To do so we need to call `SystemParametersInfo` with `SPI_GETMOUSE`. It has an array of 3 elements as its third parameter. I'm new to PInvoke and I've tried many signatures but so far no luck. Here is what I've tried for the signature: ``` [DllImport("user32.dll", SetLastError = true)] [return: MarshalAs(UnmanagedType.Bool)] static extern bool SystemParametersInfo(uint uiAction, uint uiParam, [MarshalAs(UnmanagedType.LPArray)] ref long[] vparam, SPIF fWinIni); static extern bool SystemParametersInfo(uint uiAction, uint uiParam, ref long[] vparam, SPIF fWinIni); ``` None of the above worked for me and here's the exception I'm getting: `System.AccessViolationException`: Attempted to read or write protected memory. This is often an indication that other memory is corrupt. While searching I came up with this which is in VB. Solution: Thanks to GWLlosa's answer and this one I came up with the solution: ``` [DllImport("user32.dll", EntryPoint = "SystemParametersInfo", SetLastError = true)] public static extern bool SystemParametersInfoGet(uint action, uint param, IntPtr vparam, SPIF fWinIni); public const UInt32 SPI_GETMOUSE = 0x0003; [DllImport("user32.dll", EntryPoint = "SystemParametersInfo", SetLastError = true)] public static extern bool SystemParametersInfoSet(uint action, uint param, IntPtr vparam, SPIF fWinIni); public const UInt32 SPI_SETMOUSE = 0x0004; public static bool ToggleEnhancePointerPrecision(bool b) { int[] mouseParams = new int[3]; // Get the current values. SystemParametersInfoGet(SPI_GETMOUSE, 0, GCHandle.Alloc(mouseParams, GCHandleType.Pinned).AddrOfPinnedObject(), 0); // Modify the acceleration value as directed. mouseParams[2] = b ? 1 : 0; // Update the system setting. return SystemParametersInfoSet(SPI_SETMOUSE, 0, GCHandle.Alloc(mouseParams, GCHandleType.Pinned).AddrOfPinnedObject(), SPIF.SPIF_SENDCHANGE); } ``` Also this documentation proved to be helpful.