如何将UCHAR虚拟密钥代码转换为std::string

Question

我正在开发一个可以更改键盘设置的游戏选项。所以，我想显示玩家已经更改的密钥。我遇到了将包含虚拟密钥代码的UCHAR密钥转换为std:：string的问题。似乎GetKeyNameText()只能将UCHAR转换为字符串，因为屏幕上没有显示任何字符串。如何解决此问题？谢谢

获取键盘信息

LRESULT Game::messageHandler(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
if (initialized)    // do not process messages if not initialized
{
switch (msg)
{
case WM_KEYDOWN: case WM_SYSKEYDOWN:       // key down
input->keyDown(wParam);
return 0;
}
}
return DefWindowProc(hwnd, msg, wParam, lParam);    // let Windows handle it
}

输入类

UCHAR key;  
void Input::keyDown(WPARAM wParam)
{
// make sure key code is within buffer range
if (wParam < inputNS::KEYS_ARRAY_LEN)
{
keysDown[wParam] = true;    // update keysDown array
// key has been "pressed, erased by clear()
keysPressed[wParam] = true; // update keysPressed array
key = wParam;
}
}
UCHAR getKeyPressed() { return key; }

游戏类

注意：已跳过代码详细信息。

// Key control
UCHAR vkeyUp;
UCHAR vkeyDown;
void GameContent::update()
{
if (buttonX == 220)
{
if (buttonY == 15)
{
if (input->anyKeyPressed()) {
vkeyUp = input->getKeyPressed();
buttonX = 10;
buttonY = 15;
}   
}
else if (buttonY == 65)
{
if (input->anyKeyPressed()) {
vkeyDown = input->getKeyPressed();
buttonX = 10;
buttonY = 65;
}
}
}
button.setX(buttonX);
button.setY(buttonY);
}

void GameContent::render()
{
font.print("Move Up", 20, 20);      font.print(input->getKeyPressedString(vkeyUp), 300, 20);
font.print("Move Down", 20, 70);    font.print(input->getKeyPressedString(vkeyDown), 300, 70);
}

std::string Input::getKeyPressedString(UCHAR vkey)
{
std::string keyString;
TCHAR *lpszName = new TCHAR[256];
GetKeyNameText(vkey, lpszName, sizeof(lpszName));
keyString = *lpszName;
return keyString;
}

DirectX字体类

int TextDX::print(const std::string &str, int x, int y)
{
if (dxFont == NULL)
return 0;
// Set font position
fontRect.top = y;
fontRect.left = x;
// Rotation center
D3DXVECTOR2 rCenter = D3DXVECTOR2((float)x, (float)y);
// Setup matrix to rotate text by angle
D3DXMatrixTransformation2D(&matrix, NULL, 0.0f, NULL, &rCenter, angle, NULL);
// Apply Matrix
graphics->getSprite()->SetTransform(&matrix);
return dxFont->DrawTextA(graphics->getSprite(), str.c_str(), -1, &fontRect, DT_LEFT, color);
}

Answer 1

getKeyPressedString中的三个问题：
1)您不会再删除lpszName
在返回之前生成delete lpszName;，
或者首先使用静态缓冲区。

2)keyString = *lpszName;只分配第一个字符，而不是整个字符串
删除*。

3)GetKeyNameText可能会失败。检查返回值，并检查GetLastError
(旁注：密钥名和256不会出现ERROR_INSUFFICIENT_BUFFER)。

代码：

std::string Input::getKeyPressedString(UCHAR vkey)
{
TCHAR lpszName[256];
if(!GetKeyNameText(vkey, lpszName, sizeof(lpszName)))
{
//maybe? Or throw std::systemerror(GetLastError(), std::system_category())
return std::string("");
}
return std::string(lpszName);
}