为什么当尝试将鼠标移动 360c 度时，鼠标光标在中间卡顿

鼠标不移动鼠标指针/光标卡在中间并结结巴巴/跳舞/摇晃。

这是我用于鼠标输入的代码：

    private void ProcessInputCamera(float amount)
    {
        previousState = currentState;
        currentState = Mouse.GetState();
        MouseState currentMouseState = Mouse.GetState();
        if (currentMouseState != originalMouseState)
        {
            float xDifference = currentMouseState.X - originalMouseState.X;
            float yDifference = currentMouseState.Y - originalMouseState.Y;
            leftrightRot -= rotationSpeed * xDifference * amount;
            updownRot -= rotationSpeed * yDifference * amount;
            Mouse.SetPosition(GraphicsDevice.Viewport.Width / 2, GraphicsDevice.Viewport.Height / 2);
        }
        Vector3 moveVector = new Vector3(0, 0, 0);
        KeyboardState keyState = Keyboard.GetState();
        if (keyState.IsKeyDown(Keys.Up) || keyState.IsKeyDown(Keys.Up))
            moveVector += new Vector3(0, 0, -1);
        if (keyState.IsKeyDown(Keys.Down) || keyState.IsKeyDown(Keys.Down))
            moveVector += new Vector3(0, 0, 1);
        if (keyState.IsKeyDown(Keys.Right) || keyState.IsKeyDown(Keys.Right))
            moveVector += new Vector3(1, 0, 0);
        if (keyState.IsKeyDown(Keys.Left) || keyState.IsKeyDown(Keys.Left))
            moveVector += new Vector3(-1, 0, 0);
        if (keyState.IsKeyDown(Keys.Q))
            moveVector += new Vector3(0, 100, 0);
        if (keyState.IsKeyDown(Keys.Z))
            moveVector += new Vector3(0, -100, 0);
        AddToCameraPosition(moveVector * amount);
    }
    private void AddToCameraPosition(Vector3 vectorToAdd)
    {
        Matrix cameraRotation = Matrix.CreateRotationX(updownRot) * Matrix.CreateRotationY(leftrightRot);
        Vector3 rotatedVector = Vector3.Transform(vectorToAdd, cameraRotation);
        cameraPosition += moveSpeed * rotatedVector;
        UpdateViewMatrix(viewMatrix);
    }
    private void UpdateViewMatrix(Matrix viewMatrix)
    {
        Matrix cameraRotation = Matrix.CreateRotationX(updownRot) * Matrix.CreateRotationY(leftrightRot);
        Vector3 cameraOriginalTarget = new Vector3(0, 0, -1);
        Vector3 cameraRotatedTarget = Vector3.Transform(cameraOriginalTarget, cameraRotation);
        Vector3 cameraFinalTarget = cameraPosition + cameraRotatedTarget;
        Vector3 cameraOriginalUpVector = new Vector3(0, 1, 0);
        Vector3 cameraRotatedUpVector = Vector3.Transform(cameraOriginalUpVector, cameraRotation);
        viewMatrix = Matrix.CreateLookAt(cameraPosition, cameraFinalTarget, cameraRotatedUpVector);
    }

钥匙正在工作，他们正在旋转地形。但是使用鼠标，我希望能够像第一人称视角一样360c度改变我的视角，而不是旋转地形，也不是旋转物体，而是让我360c环顾四周。

问题是这行：

Mouse.SetPosition(GraphicsDevice.Viewport.Width / 2, GraphicsDevice.Viewport.Height / 2);

出于某种原因，使鼠标诅咒卡在中间并跳舞/摇晃/结结巴巴。如果我取消注释此行而不使用它，那么鼠标移动很流畅，但它确实移动了任何东西 360c 度，我只能定期移动鼠标光标。

问题是为什么我不能像第一人称射击游戏中那样移动鼠标 360c？

这是 mt Game1.cs 代码，包括我标记它的相机代码。 http://pastebin.com/SF3iiftq

Mouse.SetPosition(GraphicsDevice.Viewport.Width / 2, GraphicsDevice.Viewport.Height / 2);