KeyPress和KeyDown/KeyUp

(1) KeyPress 和KeyDown 、KeyUp之间的区别：
    1）.KeyPress主要用来捕获数字(注意：包括Shift+数字的符号)、字母（注意：包括大小写）、小键盘等除了F1-12、SHIFT、Alt、Ctrl、Insert、Home、PgUp、Delete、End、PgDn、ScrollLock、Pause、NumLock、{菜单键}、{开始键}和方向键外的ANSI字符
        KeyDown 和KeyUp 通常可以捕获键盘除了PrScrn所有按键(这里不讨论特殊键盘的特殊键）
    2）.KeyPress 只能捕获单个字符
        KeyDown 和KeyUp 可以捕获组合键。
    3）.KeyPress 可以捕获单个字符的大小写
    4）.KeyDown和KeyUp 对于单个字符捕获的KeyValue 都是一个值，也就是不能判断单个字符的大小写。
    5）.KeyPress 不区分小键盘和主键盘的数字字符。
        KeyDown 和KeyUp 区分小键盘和主键盘的数字字符。
    6）.其中PrScrn 按键KeyPress、KeyDown和KeyUp 都不能捕获。

(2)KeyPress事件：
private void Form1_KeyPress(object sender, KeyPressEventArgs e)
{
    if(e.KeyChar== '1')
    {
        button1.PerformClick();// 执行按钮“1”的操作
        e.Handled = true;
    }
}
KeyChar取值：

另外2个特殊ASCII码：回车=13，换行=10

(3)KeyDown事件：

private void Form1_KeyDown(object sender, KeyEventArgs e)
{
       Keys key = e.KeyCode;
       if (e.Control!=true)//如果没按Ctrl键
return;
       switch (key)
       {
            case Keys.NumPad0:
                //按下小键盘0以后
                break;
            case Keys.NumPad1:
                //按下小键盘1以后
                break;
            case Keys.S:
                //按下S键以后
                break;
            case Keys.Up:
                //按下向下键以后
                break;
       }
}

KeyCode取值:

keycode    8 = BackSpace BackSpace    keycode    9 = Tab Tab    keycode   12 = Clear

keycode   13 = Enter     keycode   16 = Shift_L      keycode   17 = Control_L

keycode   18 = Alt_L     keycode   19 = Pause      keycode   20 = Caps_Lock

keycode   27 = Escape Escape    keycode   32 = space space     keycode   33 = Prior

keycode   34 = Next    keycode   35 = End       keycode   36 = Home

keycode   37 = Left     keycode   38 = Up       keycode   39 = Right

keycode   40 = Down
keycode   41 = Select
keycode   42 = Print
keycode   43 = Execute
keycode   45 = Insert
keycode   46 = Delete
keycode   47 = Help
keycode   48 = 0 equal braceright
keycode   49 = 1 exclam onesuperior
keycode   50 = 2 quotedbl twosuperior
keycode   51 = 3 section threesuperior
keycode   52 = 4 dollar
keycode   53 = 5 percent
keycode   54 = 6 ampersand
keycode   55 = 7 slash braceleft
keycode   56 = 8 parenleft bracketleft
keycode   57 = 9 parenright bracketright
keycode   65 = a A
keycode   66 = b B
keycode   67 = c C
keycode   68 = d D
keycode   69 = e E EuroSign
keycode   70 = f F
keycode   71 = g G
keycode   72 = h H
keycode   73 = i I
keycode   74 = j J
keycode   75 = k K
keycode   76 = l L
keycode   77 = m M mu
keycode   78 = n N
keycode   79 = o O
keycode   80 = p P
keycode   81 = q Q at
keycode   82 = r R
keycode   83 = s S
keycode   84 = t T
keycode   85 = u U
keycode   86 = v V
keycode   87 = w W
keycode   88 = x X
keycode   89 = y Y
keycode   90 = z Z
keycode   96 = KP_0 KP_0
keycode   97 = KP_1 KP_1
keycode   98 = KP_2 KP_2
keycode   99 = KP_3 KP_3
keycode 100 = KP_4 KP_4
keycode 101 = KP_5 KP_5
keycode 102 = KP_6 KP_6
keycode 103 = KP_7 KP_7
keycode 104 = KP_8 KP_8
keycode 105 = KP_9 KP_9
keycode 106 = KP_Multiply KP_Multiply
keycode 107 = KP_Add KP_Add
keycode 108 = KP_Separator KP_Separator
keycode 109 = KP_Subtract KP_Subtract
keycode 110 = KP_Decimal KP_Decimal
keycode 111 = KP_Divide KP_Divide
keycode 112 = F1
keycode 113 = F2
keycode 114 = F3
keycode 115 = F4
keycode 116 = F5
keycode 117 = F6
keycode 118 = F7
keycode 119 = F8
keycode 120 = F9
keycode 121 = F10
keycode 122 = F11
keycode 123 = F12
keycode 124 = F13
keycode 125 = F14
keycode 126 = F15
keycode 127 = F16
keycode 128 = F17
keycode 129 = F18
keycode 130 = F19
keycode 131 = F20
keycode 132 = F21
keycode 133 = F22
keycode 134 = F23
keycode 135 = F24
keycode 136 = Num_Lock
keycode 137 = Scroll_Lock
keycode 187 = acute grave
keycode 188 = comma semicolon
keycode 189 = minus underscore
keycode 190 = period colon
keycode 192 = numbersign apostrophe
keycode 210 = plusminus hyphen macron
keycode 211 =
keycode 212 = copyright registered
keycode 213 = guillemotleft guillemotright
keycode 214 = masculine ordfeminine
keycode 215 = ae AE
keycode 216 = cent yen
keycode 217 = questiondown exclamdown
keycode 218 = onequarter onehalf threequarters
keycode 220 = less greater bar
keycode 221 = plus asterisk asciitilde
keycode 227 = multiply division
keycode 228 = acircumflex Acircumflex
keycode 229 = ecircumflex Ecircumflex
keycode 230 = icircumflex Icircumflex
keycode 231 = ocircumflex Ocircumflex
keycode 232 = ucircumflex Ucircumflex
keycode 233 = ntilde Ntilde
keycode 234 = yacute Yacute
keycode 235 = oslash Ooblique
keycode 236 = aring Aring
keycode 237 = ccedilla Ccedilla
keycode 238 = thorn THORN
keycode 239 = eth ETH
keycode 240 = diaeresis cedilla currency
keycode 241 = agrave Agrave atilde Atilde
keycode 242 = egrave Egrave
keycode 243 = igrave Igrave
keycode 244 = ograve Ograve otilde Otilde
keycode 245 = ugrave Ugrave
keycode 246 = adiaeresis Adiaeresis
keycode 247 = ediaeresis Ediaeresis
keycode 248 = idiaeresis Idiaeresis
keycode 249 = odiaeresis Odiaeresis
keycode 250 = udiaeresis Udiaeresis
keycode 251 = ssharp question backslash
keycode 252 = asciicircum degree
keycode 253 = 3 sterling
keycode 254 = Mode_switch