blocks|key|2319067|text|getch+()函数返回箭头键(和其他一些特殊键)的两个键代码，如FatalError的注释中所述。它首先返回0+(0x00)或224+(0xE0)，然后返回标识所按键的代码。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2319068|对于箭头键，它首先返回224，然后返回72+(向上)、80+(向下)、75+(左)和77+(右)。如果按下数字键盘箭头键(在NumLock关闭的情况下)，则getch+()首先返回0，而不是224。|2319069|请注意，getch+()没有以任何方式标准化，并且这些代码可能因编译器而异。这些代码由Windows上的MinGW和Visual+C%2B%2B返回。|2319070|要查看getch+()对各种键的操作，一个方便的程序是：|2319071|#include+<stdio.h>
#include+<conio.h>

int+main+()
{
++++int+ch;

++++while+((ch+=+_getch())+!=+27)+/*+27+=+Esc+key+*/
++++{
++++++++printf("%25d",+ch);
++++++++if+(ch+==+0+%7C%7C+ch+==+224)
++++++++++++printf+(",+%25d",+_getch+());+
++++++++printf("\n");
++++}

++++printf("ESC+%25d\n",+ch);

++++return+(0);
}|code-block|syntax|javascript|2319072|这适用于MinGW和可视化C%2B%2B。这些编译器使用名称_getch+()而不是getch+()来表示它是一个非标准函数。|2319073|所以，你可以这样做：|2319074|ch+=+_getch+();
if+(ch+==+0+%7C%7C+ch+==+224)
{
++++switch+(_getch+())
++++{
++++++++case+72:
++++++++++++/*+Code+for+up+arrow+handling+*/
++++++++++++break;

++++++++case+80:
++++++++++++/*+Code+for+down+arrow+handling+*/
++++++++++++break;

++++++++/*+...+etc+...+*/
++++}
}|2319075|entityMap^0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|V|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|W|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|X|8|@]|9|@]|A|$]]|$1|H|3|I|5|J|7|Y|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|Z|8|@]|9|@]|A|$]]|$1|O|3|P|5|6|7|10|8|@]|9|@]|A|$]]|$1|Q|3|R|5|J|7|11|8|@]|9|@]|A|$K|L]]|$1|S|3|-4|5|6|7|12|8|@]|9|@]|A|$]]]|T|$]]

getch () function returns two keycodes for arrow keys (and some other special keys), as mentioned in the comment by FatalError. It returns either 0 (0x00) or 224 (0xE0) first, and then returns a code identifying the key that was pressed.

For the arrow keys, it returns 224 first followed by 72 (up), 80 (down), 75 (left) and 77 (right). If the num-pad arrow keys (with NumLock off) are pressed, getch () returns 0 first instead of 224.

Please note that getch () is not standardized in any way, and these codes might vary from compiler to compiler. These codes are returned by MinGW and Visual C++ on Windows.

A handy program to see the action of getch () for various keys is:

<pre><code>#include &lt;stdio.h&gt;
#include &lt;conio.h&gt;

int main ()
{
 int ch;

 while ((ch = _getch()) != 27) /* 27 = Esc key */
 {
 printf("%d", ch);
 if (ch == 0 || ch == 224)
 printf (", %d", _getch ()); 
 printf("\n");
 }

 printf("ESC %d\n", ch);

 return (0);
}
</code></pre>

This works for MinGW and Visual C++. These compilers use the name _getch () instead of getch () to indicate that it is a non-standard function.

So, you may do something like:

<pre><code>ch = _getch ();
if (ch == 0 || ch == 224)
{
 switch (_getch ())
 {
 case 72:
 /* Code for up arrow handling */
 break;

 case 80:
 /* Code for down arrow handling */
 break;

 /* ... etc ... */
 }
}
</code></pre>

blocks|key|2133926|text|按下一个箭头键，getch会将三个值推入缓冲区：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2133927|2133928|'\033'|unordered-list-item|2133929|'['|2133930|'A'，'B'、'C'或'D'|2133931|2133932|所以代码应该是这样的：|2133933|if+(getch()+==+'\033')+{+//+if+the+first+value+is+esc
++++getch();+//+skip+the+[
++++switch(getch())+{+//+the+real+value
++++++++case+'A':
++++++++++++//+code+for+arrow+up
++++++++++++break;
++++++++case+'B':
++++++++++++//+code+for+arrow+down
++++++++++++break;
++++++++case+'C':
++++++++++++//+code+for+arrow+right
++++++++++++break;
++++++++case+'D':
++++++++++++//+code+for+arrow+left
++++++++++++break;
++++}
}|code-block|syntax|javascript|2133934|entityMap^0|8|5|0|0|0|6|0|0|3|0|0|3|4|3|8|3|C|3|0|0|0|0^^$0|@$1|2|3|4|5|6|7|X|8|@$9|Y|A|Z|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|10|8|@]|D|@]|E|$]]|$1|G|3|H|5|I|7|11|8|@$9|12|A|13|B|C]]|D|@]|E|$]]|$1|J|3|K|5|I|7|14|8|@$9|15|A|16|B|C]]|D|@]|E|$]]|$1|L|3|M|5|I|7|17|8|@$9|18|A|19|B|C]|$9|1A|A|1B|B|C]|$9|1C|A|1D|B|C]|$9|1E|A|1F|B|C]]|D|@]|E|$]]|$1|N|3|-4|5|6|7|1G|8|@]|D|@]|E|$]]|$1|O|3|P|5|6|7|1H|8|@]|D|@]|E|$]]|$1|Q|3|R|5|S|7|1I|8|@]|D|@]|E|$T|U]]|$1|V|3|-4|5|6|7|1J|8|@]|D|@]|E|$]]]|W|$]]

By pressing one arrow key <code>getch</code> will push three values into the buffer:

<ul>
<li><code>'\033'</code></li>
<li><code>'['</code></li>
<li><code>'A'</code>, <code>'B'</code>, <code>'C'</code> or <code>'D'</code></li>
</ul>

So the code will be something like this:

<pre><code>if (getch() == '\033') { // if the first value is esc
 getch(); // skip the [
 switch(getch()) { // the real value
 case 'A':
 // code for arrow up
 break;
 case 'B':
 // code for arrow down
 break;
 case 'C':
 // code for arrow right
 break;
 case 'D':
 // code for arrow left
 break;
 }
}
</code></pre>

blocks|key|2133959|text|所以，经过一番努力，我奇迹般地解决了这个烦人的问题！我试图模仿一个linux终端，但在它保存命令历史的部分卡住了，可以通过按向上或向下箭头键来访问。我发现ncurses+lib很难理解，学习起来也很慢。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2133960|char+ch+=+0,+k+=+0;
while(1)
{
++ch+=+getch();
++if(ch+==+27)++++++++++++++++++//+if+ch+is+the+escape+sequence+with+num+code+27,+k+turns+1+to+signal+the+next
++++k+=+1;
++if(ch+==+91+&&+k+==+1)+++++++//+if+the+previous+char+was+27,+and+the+current+91,+k+turns+2+for+further+use
++++k+=+2;
++if(ch+==+65+&&+k+==+2)+++++++//+finally,+if+the+last+char+of+the+sequence+matches,+you've+got+a+key+!
++++printf("You+pressed+the+up+arrow+key+!!\n");
++if(ch+==+66+&&+k+==+2)+++++++++++++++++++++++++++++
++++printf("You+pressed+the+down+arrow+key+!!\n");
++if(ch+!=+27+&&+ch+!=+91)++++++//+if+ch+isn't+either+of+the+two,+the+key+pressed+isn't+up/down+so+reset+k
++++k+=+0;
++printf("%25c+-+%25d",+ch,+ch);++++//+prints+out+the+char+and+it's+int+code|code-block|syntax|javascript|2133961|这有点大胆，但它解释了很多东西。祝你好运！|2133962|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

So, after alot of struggle, I miraculously solved this everannoying issue !
I was trying to mimic a linux terminal and got stuck at the part where it keeps a command history which can be accessed by pressing up or down arrow keys. I found ncurses lib to be painfuly hard to comprehend and slow to learn.

<pre><code>char ch = 0, k = 0;
while(1)
{
 ch = getch();
 if(ch == 27) // if ch is the escape sequence with num code 27, k turns 1 to signal the next
 k = 1;
 if(ch == 91 &amp;&amp; k == 1) // if the previous char was 27, and the current 91, k turns 2 for further use
 k = 2;
 if(ch == 65 &amp;&amp; k == 2) // finally, if the last char of the sequence matches, you've got a key !
 printf("You pressed the up arrow key !!\n");
 if(ch == 66 &amp;&amp; k == 2) 
 printf("You pressed the down arrow key !!\n");
 if(ch != 27 &amp;&amp; ch != 91) // if ch isn't either of the two, the key pressed isn't up/down so reset k
 k = 0;
 printf("%c - %d", ch, ch); // prints out the char and it's int code
</code></pre>

It's kind of bold but it explains alot. Good luck !

blocks|key|2134005|text|实际上，要读取箭头键，需要读取其扫描码。以下是通过按箭头键(而不是释放键)生成的扫描码|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2134006|num+Lock关闭时的|2134007|blockquote|2134008|2134009|2134010|2134011|Left+E0+4B+|unordered-list-item|2134012|Right+E0+4D+|2134013|Up+E0+48+|2134014|Down+E0+50|2134015|2134016|当数字锁定在这些键上时，这些键的前面带有E0+2A|offset|length|style|BOLD|2134017|2134018|2134019|字节E0为-32|2134020|字节48为72向上|2134021|字节50为向下80|2134022|2134023|user_var=getch()；if(user_var+==+-32)+{+user_var=getch()；switch(user_var)+{案例72:+cur_sel--；if+(cur_sel==0)+cur_sel=4；break；案例80:+cur_sel%2B%2B；if(cur_sel==5)+cur_sel=1；break；}+}|2134024|在上面的代码中，我假设程序员只想移动4行。|2134025|entityMap^0|0|0|0|0|0|0|0|0|0|0|0|K|5|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|1D|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|1E|8|@]|9|@]|A|$]]|$1|D|3|-4|5|E|7|1F|8|@]|9|@]|A|$]]|$1|F|3|-4|5|6|7|1G|8|@]|9|@]|A|$]]|$1|G|3|-4|5|6|7|1H|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|1I|8|@]|9|@]|A|$]]|$1|I|3|J|5|K|7|1J|8|@]|9|@]|A|$]]|$1|L|3|M|5|K|7|1K|8|@]|9|@]|A|$]]|$1|N|3|O|5|K|7|1L|8|@]|9|@]|A|$]]|$1|P|3|Q|5|K|7|1M|8|@]|9|@]|A|$]]|$1|R|3|-4|5|6|7|1N|8|@]|9|@]|A|$]]|$1|S|3|T|5|6|7|1O|8|@$U|1P|V|1Q|W|X]]|9|@]|A|$]]|$1|Y|3|-4|5|6|7|1R|8|@]|9|@]|A|$]]|$1|Z|3|-4|5|6|7|1S|8|@]|9|@]|A|$]]|$1|10|3|11|5|K|7|1T|8|@]|9|@]|A|$]]|$1|12|3|13|5|K|7|1U|8|@]|9|@]|A|$]]|$1|14|3|15|5|K|7|1V|8|@]|9|@]|A|$]]|$1|16|3|-4|5|6|7|1W|8|@]|9|@]|A|$]]|$1|17|3|18|5|6|7|1X|8|@]|9|@]|A|$]]|$1|19|3|1A|5|6|7|1Y|8|@]|9|@]|A|$]]|$1|1B|3|-4|5|6|7|1Z|8|@]|9|@]|A|$]]]|1C|$]]

Actually, to read arrow keys one need to read its scan code.
Following are the scan code generated by arrow keys press (not key release)

<blockquote>
 When num Lock is off
</blockquote>

<ul>
<li>Left E0 4B </li>
<li>Right E0 4D </li>
<li>Up E0 48 </li>
<li>Down E0 50</li>
</ul>

<blockquote>
 When Num Lock is on these keys get preceded with E0 2A
</blockquote>

<ul>
<li>Byte E0 is -32</li>
<li>Byte 48 is 72 UP</li>
<li>Byte 50 is 80 DOWN

<pre><code>user_var=getch();
if(user_var == -32)
{
 user_var=getch();
 switch(user_var)
 {
 case 72:
 cur_sel--;
 if (cur_sel==0)
 cur_sel=4;
 break;
 case 80:
 cur_sel++;
 if(cur_sel==5)
 cur_sel=1;
 break;

 }
}
</code></pre></li>
</ul>

In the above code I have assumed programmer wants to move 4 lines only.

blocks|key|496103|text|keypad将允许用户终端的键盘允许将功能键解释为单个值(即，无转义序列)。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|496104|如手册页中所述：|496105|496106|键盘选项启用用户终端的键盘。如果启用(bf为TRUE)，用户可以按下功能键(如箭头键)，wgetch将返回表示该功能键的单个值，就像在KEY_LEFT中一样。如果禁用(bf为FALSE)，curses不会特殊对待功能键，程序必须自己解释转义序列。如果终端中的小键盘可以打开(发送)和关闭(在本地工作)，则打开此选项会在调用wgetch时打开终端小键盘。键盘的默认值为false。|blockquote|496107|496108|entityMap|0|LINK|mutability|MUTABLE|url|https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwiyh4CDh9rJAhUGWh4KHVaFALoQFggdMAA&url=http%253A%252F%252Ftldp.org%252FHOWTO%252FNCURSES-Programming-HOWTO%252Finit.html&usg=AFQjCNEO9S-SfKuuqnZmD7w8ZGK2gotXFw&sig2=5-TU9M0f2JcQW80oblYoOw^0|0|6|0|6|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@$9|X|A|Y|1|Z]]|E|$]]|$1|F|3|G|5|6|7|10|8|@]|D|@]|E|$]]|$1|H|3|-4|5|6|7|11|8|@]|D|@]|E|$]]|$1|I|3|J|5|K|7|12|8|@]|D|@]|E|$]]|$1|L|3|-4|5|6|7|13|8|@]|D|@]|E|$]]|$1|M|3|-4|5|6|7|14|8|@]|D|@]|E|$]]]|N|$O|$5|P|Q|R|E|$S|T]]]]

The <a href="https://www.google.com/url?sa=t&amp;rct=j&amp;q=&amp;esrc=s&amp;source=web&amp;cd=1&amp;cad=rja&amp;uact=8&amp;ved=0ahUKEwiyh4CDh9rJAhUGWh4KHVaFALoQFggdMAA&amp;url=http%3A%2F%2Ftldp.org%2FHOWTO%2FNCURSES-Programming-HOWTO%2Finit.html&amp;usg=AFQjCNEO9S-SfKuuqnZmD7w8ZGK2gotXFw&amp;sig2=5-TU9M0f2JcQW80oblYoOw" rel="nofollow"><code>keypad</code></a> will allow the keyboard of the user's terminal to allow for function keys to be interpreted as a single value (i.e. no escape sequence).

As stated in the man page:

<blockquote>
 The keypad option enables the keypad of the user's terminal. If
 enabled (bf is TRUE), the user can press a function key (such as an
 arrow key) and wgetch returns a single value representing the function
 key, as in KEY_LEFT. If disabled (bf is FALSE), curses does not treat
 function keys specially and the program has to interpret the escape
 sequences itself. If the keypad in the terminal can be turned on (made
 to transmit) and off (made to work locally), turning on this option
 causes the terminal keypad to be turned on when wgetch is called. The
 default value for keypad is false.
</blockquote>

blocks|key|496122|text|有关使用带有工作代码和ncurses初始化的ncurses的解决方案，请参见getchar()+returns+the+same+value+(27)+for+up+and+down+arrow+keys|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|496123|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/15306463/getchar-returns-the-same-value-27-for-up-and-down-arrow-keys^0|M|7|12|1S|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@$9|O|A|P|B|C]]|D|@$9|Q|A|R|1|S]]|E|$]]|$1|F|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|G|$H|$5|I|J|K|E|$L|M]]]]

for a solution that uses <code>ncurses</code> with working code and initialization of ncurses see <a href="https://stackoverflow.com/questions/15306463/getchar-returns-the-same-value-27-for-up-and-down-arrow-keys">getchar() returns the same value (27) for up and down arrow keys</a>

blocks|key|1299619|text|我已经使用getch编写了一个函数来获取箭头代码。这是一个快速的解决方案，但是函数将根据箭头键返回一个ASCII代码:向上：-10向下：-11向右：-12向左：-13|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1299620|此外，使用此功能，您将能够区分退出触摸和箭头键。但您必须按ESC+2次才能激活ESC键。|1299621|代码如下：|1299622|char+getch_hotkey_upgrade(void)
{
++char+ch+=+0,ch_test[3]+=+{0,0,0};

++++ch_test[0]=getch();

++++if(ch_test[0]+==+27)
++++{
++++++++ch_test[1]=getch();

++++++++if+(ch_test[1]==+91)
++++++++{
++++++++++++ch_test[2]=getch();

++++++++++++switch(ch_test[2])
++++++++++++{
++++++++++++case+'A':
++++++++++++++++//printf("You+pressed+the+up+arrow+key+!!\n");
++++++++++++++++//ch+=+-10;
++++++++++++++++ch+=+-10;
++++++++++++++++break;
++++++++++++case+'B':
++++++++++++++++//printf("You+pressed+the+down+arrow+key+!!\n");
++++++++++++++++ch+=+-11;
++++++++++++++++break;
++++++++++++case+'C':
++++++++++++++++//printf("You+pressed+the+right+arrow+key+!!\n");
++++++++++++++++ch+=+-12;
++++++++++++++++break;
++++++++++++case+'D':
++++++++++++++++//printf("You+pressed+the+left+arrow+key+!!\n");
++++++++++++++++ch+=+-13;
++++++++++++++++break;
++++++++++++}
++++++++}
++++++++else
+++++++++ch+=+ch_test+[1];
++++}
++++else
++++++++ch+=+ch_test+[0];
++return+ch;
}|code-block|syntax|javascript|1299623|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|O|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|P|8|@]|9|@]|A|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

I have written a function using getch to get arrow code. it's a quick'n'dirty solution but the function will return an ASCII code depending on arrow key : 
UP : -10
DOWN : -11
RIGHT : -12
LEFT : -13

Moreover,with this function, you will be able to differenciate the ESCAPE touch and the arrow keys. But you have to press ESC 2 time to activate the ESC key.

here the code : 

<pre><code>char getch_hotkey_upgrade(void)
{
 char ch = 0,ch_test[3] = {0,0,0};

 ch_test[0]=getch();

 if(ch_test[0] == 27)
 {
 ch_test[1]=getch();

 if (ch_test[1]== 91)
 {
 ch_test[2]=getch();

 switch(ch_test[2])
 {
 case 'A':
 //printf("You pressed the up arrow key !!\n");
 //ch = -10;
 ch = -10;
 break;
 case 'B':
 //printf("You pressed the down arrow key !!\n");
 ch = -11;
 break;
 case 'C':
 //printf("You pressed the right arrow key !!\n");
 ch = -12;
 break;
 case 'D':
 //printf("You pressed the left arrow key !!\n");
 ch = -13;
 break;
 }
 }
 else
 ch = ch_test [1];
 }
 else
 ch = ch_test [0];
 return ch;
}
</code></pre>

blocks|key|2134140|text|我只是个初学者，但我已经创建了一个char(for+example+"b")，我执行b+=+_getch();+(这是一个conio.h库的命令)并检查|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2134141|If+(b+==+-32)
b+=+_getch();|code-block|syntax|javascript|2134142|并检查按键(向上72，向下80，向右77，向左75+)|2134143|entityMap^0|H|L|16|D|1P|7|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]|$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|V|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|W|8|@]|D|@]|E|$]]|$1|M|3|-4|5|6|7|X|8|@]|D|@]|E|$]]]|N|$]]

I'm Just a starter, but i'v created a <code>char(for example "b")</code>, and I do <code>b = _getch();</code> (its a <code>conio.h</code> library's command)
And check

<pre><code>If (b == -32)
b = _getch();
</code></pre>

And do check for the keys (72 up, 80 down, 77 right, 75 left)

blocks|key|1301306|text|试试这个怎么样？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1301307|void+CheckKey(void)+{
int+key;
if+(kbhit())+{
++++key=getch();
++++if+(key+==+224)+{
++++++++do+{
++++++++++++key=getch();
++++++++}+while(key==224);
++++++++switch+(key)+{
++++++++++++case+72:
++++++++++++++++printf("up");
++++++++++++++++break;
++++++++++++case+75:
++++++++++++++++printf("left");
++++++++++++++++break;
++++++++++++case+77:
++++++++++++++++printf("right");
++++++++++++++++break;
++++++++++++case+80:
++++++++++++++++printf("down");
++++++++++++++++break;
++++++++}
++++}
++++printf("%25d\n",key);
}

int+main()+{
++++while+(1)+{
++++++++if+(kbhit())+{
++++++++++++CheckKey();
++++++++}
++++}
}|code-block|syntax|javascript|1301308|(如果你不能理解为什么有224，那么试着运行下面的代码：)|1301309|#include+<stdio.h>
#include+<conio.h>

int+main()+{
++++while+(1)+{
++++++++if+(kbhit())+{
++++++++++++printf("%25d\n",getch());
++++++++}
++++}
}|1301310|但我不知道为什么是224。如果你知道为什么，你能写下评论吗？|1301311|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

how about trying this?

<pre><code>void CheckKey(void) {
int key;
if (kbhit()) {
 key=getch();
 if (key == 224) {
 do {
 key=getch();
 } while(key==224);
 switch (key) {
 case 72:
 printf("up");
 break;
 case 75:
 printf("left");
 break;
 case 77:
 printf("right");
 break;
 case 80:
 printf("down");
 break;
 }
 }
 printf("%d\n",key);
}

int main() {
 while (1) {
 if (kbhit()) {
 CheckKey();
 }
 }
}
</code></pre>

(if you can't understand why there is 224, then try running this code: )

<pre><code>#include &lt;stdio.h&gt;
#include &lt;conio.h&gt;

int main() {
 while (1) {
 if (kbhit()) {
 printf("%d\n",getch());
 }
 }
}
</code></pre>

but I don't know why it's 224. can you write down a comment if you know why?

blocks|key|2315435|text|++++void+input_from_key_board(int+&ri,+int+&ci)
{
++++char+ch+=+'x';
++++if+(_kbhit())
++++{
++++++++ch+=+_getch();
++++++++if+(ch+==+-32)
++++++++{
++++++++++++ch+=+_getch();
++++++++++++switch+(ch)
++++++++++++{
++++++++++++case+72:+{+ri--;+break;+}
++++++++++++case+80:+{+ri%2B%2B;+break;+}
++++++++++++case+77:+{+ci%2B%2B;+break;+}
++++++++++++case+75:+{+ci--;+break;+}

++++++++++++}
++++++++}
++++++++else+if+(ch+==+'\r'){+gotoRowCol(ri%2B%2B,+ci+-=+ci);+}
++++++++else+if+(ch+==+'\t'){+gotoRowCol(ri,+ci+%2B=+5);+}
++++++++else+if+(ch+==+27)+{+system("ipconfig");+}
++++++++else+if+(ch+==+8){+cout+<<+"+";+gotoRowCol(ri,+--ci);+if+(ci+<=+0)gotoRowCol(ri--,+ci);+}
++++++++else+{+cout+<<+ch;+gotoRowCol(ri,+ci%2B%2B);+}
++++++++gotoRowCol(ri,+ci);
++++}
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|2315436|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code> void input_from_key_board(int &amp;ri, int &amp;ci)
{
 char ch = 'x';
 if (_kbhit())
 {
 ch = _getch();
 if (ch == -32)
 {
 ch = _getch();
 switch (ch)
 {
 case 72: { ri--; break; }
 case 80: { ri++; break; }
 case 77: { ci++; break; }
 case 75: { ci--; break; }

 }
 }
 else if (ch == '\r'){ gotoRowCol(ri++, ci -= ci); }
 else if (ch == '\t'){ gotoRowCol(ri, ci += 5); }
 else if (ch == 27) { system("ipconfig"); }
 else if (ch == 8){ cout &lt;&lt; " "; gotoRowCol(ri, --ci); if (ci &lt;= 0)gotoRowCol(ri--, ci); }
 else { cout &lt;&lt; ch; gotoRowCol(ri, ci++); }
 gotoRowCol(ri, ci);
 }
}
</code></pre>

blocks|key|1299660|text|试试这个。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1299661|我在Windows+7中使用Code：：Block|1299662|while+(true)
{
++++char+input;
++++input+=+getch();

++++switch(input)
++++{
++++case+-32:+//This+value+is+returned+by+all+arrow+key.+So,+we+don't+want+to+do+something.
++++++++break;
++++case+72:
++++++++printf("up");
++++++++break;
++++case+75:
++++++++printf("left");
++++++++break;
++++case+77:
++++++++printf("right");
++++++++break;
++++case+80:
++++++++printf("down");
++++++++break;
++++default:
++++++++printf("INVALID+INPUT!");
++++++++break;
++++}
}|code-block|syntax|javascript|1299663|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Try this...

I am in Windows 7 with Code::Blocks

<pre><code>while (true)
{
 char input;
 input = getch();

 switch(input)
 {
 case -32: //This value is returned by all arrow key. So, we don't want to do something.
 break;
 case 72:
 printf("up");
 break;
 case 75:
 printf("left");
 break;
 case 77:
 printf("right");
 break;
 case 80:
 printf("down");
 break;
 default:
 printf("INVALID INPUT!");
 break;
 }
}
</code></pre>

I'm writing a programm that's using <code>getch()</code> to scan for arrow keys. My code so far is:

<pre><code>switch(getch()) {
 case 65: // key up
 break;
 case 66: // key down
 break;
 case 67: // key right
 break;
 case 68: // key left
 break;
}
</code></pre>

Problem is that when I press <code>'A'</code>, <code>'B'</code>, <code>'C'</code> or <code>'D'</code> the code will also executed, because <code>65</code> is the decimal code for <code>'A'</code>, etc...

Is there a way to check for an arrow key without call others?

Thanks!

getch and arrow codes

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我正在编写一个使用getch()扫描箭头键的程序。到目前为止我的代码是：switch(getch()) {    case 65:    // key up        break;    case 66:    // key down        break;    case 67:    // key righ...

问getch和箭头代码
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