Question

控制台程序用键盘操作字符移动的小程序，请高手指点一下啊

小弟才学C++不久，不太会些程序，今天试试写了一个用键盘操作字符移动的小程序，完全控制台的，在VC++6.0下写的，弄了半天，总算可以运行了，但是很多问题，主要是我设置了一个边框范围，就是长宽各为30米的，就是想移动到边框的时候移不过去，但是实际移动到边框的时候，字符就停在那里了，回不来了，不能动了，想了半天，实在是不知道怎么解决，请高手指点一下啊，下面是代码，小弟才学不久，写的很乱，而且为了省事就用的是面向过程的方法写的，没有用类封装在一个函数里面，所以4段if语句基本是复制粘贴的，请高手看着别嫌烦啊，呵呵，先谢过了~~~~~
代码：
#include<iostream>
#include<windows.h>
using namespace std;
main()
{
int x=4;
int y=4;
HANDLE hand;
hand=GetStdHandle(STD_OUTPUT_HANDLE);
int colour=200;
int len=2;
COORD point;
point.X=x;
point.Y=y;
char *string="■";
FillConsoleOutputAttribute(hand,colour,len,point,NULL);
WriteConsoleOutputCharacter(hand,string,len,point,NULL);

INPUT_RECORD keyRec;
DWORD res;
HANDLE hnd;
hnd=GetStdHandle(STD_INPUT_HANDLE);
for(;;)
{
ReadConsoleInput(hnd,&keyRec,1,&res);
if(keyRec.EventType==KEY_EVENT)
{
if(keyRec.Event.KeyEvent.wVirtualKeyCode==65)
{
if(point.X<30&&point.X>2&&point.Y>2&&point.Y<30)
{
FillConsoleOutputAttribute(hand,1,len,point,NULL);
WriteConsoleOutputCharacter(hand," ",len,point,NULL);
point.X-=1;
FillConsoleOutputAttribute(hand,colour,len,point,NULL);
WriteConsoleOutputCharacter(hand,string,len,point,NULL);
}
else point.X+=1;
}
if(keyRec.Event.KeyEvent.wVirtualKeyCode==68)
{
if(point.X<30&&point.X>2&&point.Y>2&&point.Y<30)
{
FillConsoleOutputAttribute(hand,1,len,point,NULL);
WriteConsoleOutputCharacter(hand," ",len,point,NULL);
point.X+=1;
FillConsoleOutputAttribute(hand,colour,len,point,NULL);
WriteConsoleOutputCharacter(hand,string,len,point,NULL);
}
else point.X-=1;
}if(keyRec.Event.KeyEvent.wVirtualKeyCode==87)
{
if(point.X<30&&point.X>2&&point.Y>2&&point.Y<30)
{
FillConsoleOutputAttribute(hand,1,len,point,NULL);
WriteConsoleOutputCharacter(hand," ",len,point,NULL);
point.Y-=1;
FillConsoleOutputAttribute(hand,colour,len,point,NULL);
WriteConsoleOutputCharacter(hand,string,len,point,NULL);
}
else point.Y+=1;
}
if(keyRec.Event.KeyEvent.wVirtualKeyCode==83)
{
if(point.X<30&&point.X>2&&point.Y>2&&point.Y<30)
{
FillConsoleOutputAttribute(hand,1,len,point,NULL);
WriteConsoleOutputCharacter(hand," ",len,point,NULL);
point.Y+=1;
FillConsoleOutputAttribute(hand,colour,len,point,NULL);
WriteConsoleOutputCharacter(hand,string,len,point,NULL);
}
else point.Y-=1;
}
}
}

}
忘了说了，是按键盘 a s d w ，分别是 左 下 右 上

Answer 1

问题一：
其实主要是else语句弄巧成拙了。如果你希望point.X小于等于2的时候方块就不能往左移动了，那对应的当它小于2时，你不做任何处理，他不就停在那里不动了吗？
问题二：
最后要记得用CloseHandle关闭句柄
问题三：
两个函数的最后一个参数用NULL会出错，应该这样用：
DWORD written;
FillConsoleOutputAttribute(hand,colour,len,point,&written);
WriteConsoleOutputCharacter(hand,string,len,point,&written);
这种用法参考自：
http://hi.baidu.com/console_app/blog/item/30488bec119a5a4779f055df.html
其实我也看到网上有个教程里就这样用，但是在codeblocks下运行程序会出错，改过来就可以运行了
此外我加了一个输出方块当前位置的语句，你可以看出，由于■在dos窗口上占两个字节的宽度，因此即使你按一下方向键，对应坐标也会变化2个单位。
简单改了一下。我建议还是用函数实现好一点，因为这个程序中类似的代码段重复出现，使程序变得很长。
代码：
#include<iostream>
#include<iomanip>
#include<windows.h>
using namespace std;
int main()
{
int x=4;
int y=4;
HANDLE hand;
hand=GetStdHandle(STD_OUTPUT_HANDLE);
int colour=200;
int len=2;
COORD point;
point.X=x;
point.Y=y;
char *string="■";
SMALL_RECT rt = {0,0,35,35}; // 窗口尺寸
SetConsoleWindowInfo(hand,true,&rt); // 由于DOS默认只有25行，为了便于观察，把dos窗口行数调为35，这个也可以用system函数实现
DWORD written;
FillConsoleOutputAttribute(hand,colour,len,point,&written);
WriteConsoleOutputCharacter(hand,string,len,point,&written);
INPUT_RECORD keyRec;
DWORD res;
HANDLE hnd;
hnd=GetStdHandle(STD_INPUT_HANDLE);
for(;;)
{
cout<<setfill('0')<<"("<<setw(2)<<point.X<<","<<setw(2)<<point.Y<<")";
ReadConsoleInput(hnd,&keyRec,1,&res);
if(keyRec.EventType==KEY_EVENT)
{
if(keyRec.Event.KeyEvent.wVirtualKeyCode==65)
{
if(point.X>2) // 这里不用那么麻烦，因为按a时只会使X减小，下同
{
FillConsoleOutputAttribute(hand,1,len,point,&written);
WriteConsoleOutputCharacter(hand," ",len,point,&written);
point.X-=1;
FillConsoleOutputAttribute(hand,colour,len,point,&written);
WriteConsoleOutputCharacter(hand,string,len,point,&written);
}
}
if(keyRec.Event.KeyEvent.wVirtualKeyCode==68)
{
if(point.X<30)
{
FillConsoleOutputAttribute(hand,1,len,point,&written);
WriteConsoleOutputCharacter(hand," ",len,point,&written);
point.X+=1;
FillConsoleOutputAttribute(hand,colour,len,point,&written);
WriteConsoleOutputCharacter(hand,string,len,point,&written);
}

}
if(keyRec.Event.KeyEvent.wVirtualKeyCode==87)
{
if(point.Y>2)
{
FillConsoleOutputAttribute(hand,1,len,point,&written);
WriteConsoleOutputCharacter(hand," ",len,point,&written);
point.Y-=1;
FillConsoleOutputAttribute(hand,colour,len,point,&written);
WriteConsoleOutputCharacter(hand,string,len,point,&written);
}
}
if(keyRec.Event.KeyEvent.wVirtualKeyCode==83)
{
if(point.Y<30)
{
FillConsoleOutputAttribute(hand,1,len,point,&written);
WriteConsoleOutputCharacter(hand," ",len,point,&written);
point.Y+=1;
FillConsoleOutputAttribute(hand,colour,len,point,&written);
WriteConsoleOutputCharacter(hand,string,len,point,&written);
}
}
}
cout<<"\b\b\b\b\b\b\b";
}
// 最后记得关闭
CloseHandle(hand);
CloseHandle(hnd);
return 0;
}