不确定为什么代码不能C++简单

试图阻止用户输入字符。这段代码在我的脑海中很有意义。我所做的第一个 if 语句按预期工作（它阻止用户输入字符）。但是，当用户做出正确的选择时，开关将直接进入默认情况。在我输入错误处理 if 语句之前，开关工作正常。为帮助干杯

void Input()
{
char errorhandle;
int a;
cout << "It's " << player << "'s turn Enter where you want your shape: ";
cin >> errorhandle;
if (errorhandle < '0' || errorhandle > '9')
{
    cout << "You have not entered a number try again!" << endl;
    Input();
}
else
{
    a = (int)errorhandle;
}
switch (a)
{
case 1:
    if (board[0][0] == '1')
    {
        board[0][0] = player;
    }
    else
    {
        cout << "The place is already in use, try again!" << endl;
        Input();
    };
    break;
case 2:
    if (board[0][1] == '2')
    {
        board[0][1] = player;
    }
    else
    {
        cout << "The place is already in use, try again!" << endl;
        Input();
    };
    break;
case 3:
    if (board[0][2] == '3')
    {
        board[0][2] = player;
    }
    else
    {
        cout << "The place is already in use, try again!" << endl;
        Input();
    };
    break;
case 4:
    if (board[1][0] == '4')
    {
        board[1][0] = player;
    }
    else
    {
        cout << "The place is already in use, try again!" << endl;
        Input();
    };
    break;
case 5:
    if (board[1][1] == '5')
    {
        board[1][1] = player;
    }
    else
    {
        cout << "The place is already in use, try again!" << endl;
        Input();
    };
    break;
case 6:
    if (board[1][2] == '6')
    {
        board[1][2] = player;
    }
    else
    {
        cout << "The place is already in use, try again!" << endl;
        Input();
    };
    break;
case 7:
    if (board[2][0] == '7')
    {
        board[2][0] = player;
    }
    else
    {
        cout << "The place is already in use, try again!" << endl;
        Input();
    };
    break;
case 8:
    if (board[2][1] == '8')
    {
        board[2][1] = player;
    }
    else
    {
        cout << "The place is already in use, try again!" << endl;
        Input();
    };
    break;
case 9:
    if (board[2][2] == '9')
    {
        board[2][2] = player;
    }
    else
    {
        cout << "The place is already in use, try again!" << endl;
        Input();
    };
    break;
default:
    cout << "You have entered an invalid option, try again" << endl;
    Input();
}

}