C# 纯text文本字符添加上下角标

工作的需求，需要在GridView列HeaderText中插入带入带有上标和下标的字符串，比如这样的一个字符串： $0_{2}$ 。。

　　解决办法：使用转义字符加Unicode的NumEntity就可以实现了。定义 $0_{2}$ 字符串如下："O₂"。其中O₂为 $_{2}$ 。

实现：

效果：

　　一些常用字符如下：

Common Arithmetic & Alebgra

Character Name	Character	Entity	Num Entity	Hex Entity
LESS THAN	<	<	<	<
GREATER THAN	>	>	>	>
LESS THAN OR EQUAL TO	≤	≤	≤	≤
GREATER THAN OR EQUAL TO	≥	≥	≥	≥
PLUS OR MINUS	±	±	±	±
NOT EQUALS	≠	≠	≠	≠
DIVISION SIGN	÷	÷	÷	÷
TIMES X	×	×	×	×
MINUS	−	−	−	−
DIVISION SLASH	∕	--	∕	∕
FRACTION SLASH	⁄	&frasl	⁄	⁄
SQUARE ROOT RADICAL	√	√	√	√
CUBE ROOT	∛	--	∛	&#x221B
FOURTH ROOT	∜	--	∜	&#x221C
INFINITY	∞	∞	∞	∞
ALEF INFINITY SYMBOL	ℵ	&alefsym;	ℵ	ℵ
FUNCTION ITALIC F	ƒ	&fnof;	ƒ	ƒ
PRIME (single quote)	′	′	′	′
DOUBLE PRIME (double quote)	″	″	″	″
TRIPLE PRIME (triple quote)	‴	--	‴	‴
THEREFORE (Triangular Dots)	∴	&there4;	∴	∴
DOT OPERATOR	⋅	⋅	⋅	&#x22C5
SUPERSCRIPT TWO	¹	¹	¹	¹
SUPERSCRIPT TWO	²	²	²	²
SUPERSCRIPT THREE	³	³	³	³
LEFT ANGLE BRACKET	〈	&lang;	〈	〈
RIGHT ANGLE BRACKET	〉	&rang;	〉	〉
LEFT CEILING BRACKET	⌈	&lceil;	⌈	⌈
RIGHT CEILING BRACKET	⌉	&rceil;	⌉	⌉
LEFT FLOOR BRACKET	⌊	&lceil;	⌊	⌊
RIGHT FLOOR BRACKET	⌋	&rceil;	⌋	⌋
CIRCLED PLUS (Direct Sum)	⊕	&oplus;	⊕	&#x2295
CIRCLED TIMES (Vector Product)	⊗	&otimes;	⊗	&#x2297

Superscript Chart（上标）

Character Name	Character	Num Entity	Hex Entity
SUPERSCRIPT ZERO	⁰	⁰	&#x2070
SUPERSCRIPT ONE Entity Code = ¹	¹	¹	&#x00B9
SUPERSCRIPT TWO Entity Code = ²	²	²	&#x00B2
SUPERSCRIPT THREE Entity Code = ³	³	³	&#x00B3
SUPERSCRIPT FOUR	⁴	⁴	&#x2074
SUPERSCRIPT FIVE	⁵	⁵	&#x2075
SUPERSCRIPT SIX	⁶	⁶	&#x2076
SUPERSCRIPT SEVEN	⁷	⁷	&#x2077
SUPERSCRIPT EIGHT	⁸	⁸	&#x2078
SUPERSCRIPT NINE	⁹	⁹	&#x2079
SUPERSCRIPT PLUS SIGN	⁺	⁺	&#x207A
SUPERSCRIPT MINUS	⁻	⁻	&#x207B
SUPERSCRIPT EQUALS SIGN	⁼	⁼	&#x207C
SUPERSCRIPT LEFT PARENTHESIS	⁽	⁽	&#x207D
SUPERSCRIPT RIGHT PARENTHESIS	⁾	⁾	&#x207E
SUPERSCRIPT LATIN SMALL LETTER I	ⁱ	ⁱ	&#x2071
SUPERSCRIPT LATIN SMALL LETTER N	ⁿ	ⁿ	&#x207F

Subscript Codes（下标）

Character Name	Character	Num Entity	Hex Entity
SUBSCRIPT ZERO	₀	₀	&#x2080
SUBSCRIPT ONE	₁	₁	&#x2081
SUBSCRIPT TWO	₂	₂	&#x2082
SUBSCRIPT THREE	₃	₃	&#x2083
SUBSCRIPT FOUR	₄	₄	&#x2084
SUBSCRIPT FIVE	₅	₅	&#x2085
SUBSCRIPT SIX	₆	₆	&#x2086
SUBSCRIPT SEVEN	₇	₇	&#x2087
SUBSCRIPT EIGHT	₈	₈	&#x2088
SUBSCRIPT NINE	₉	₉	&#x2089
SUBSCRIPT PLUS SIGN	₊	₊	&#x208A
SUBSCRIPT MINUS	₋	₋	&#x208B
SUBSCRIPT EQUALS SIGN	₌	₌	&#x208C
SUBSCRIPT LEFT PARENTHESIS	₍	₍	&#x208D
SUBSCRIPT RIGHT PARENTHESIS	₎	₎	&#x208E
LATIN SUBSCRIPT SMALL LETTER A	ₐ	ₐ	&#x2090
LATIN SUBSCRIPT SMALL LETTER E	ₑ	ₑ	&#x2091
LATIN SUBSCRIPT SMALL LETTER O	ₒ	ₒ	&#x2092
LATIN SUBSCRIPT SMALL LETTER I	ᵢ	ᵢ	&#x1D62
LATIN SUBSCRIPT SMALL LETTER R	ᵣ	ᵣ	&#x1D63
LATIN SUBSCRIPT SMALL LETTER U	ᵤ	ᵤ	&#x1D64
LATIN SUBSCRIPT SMALL LETTER V	ᵥ	ᵥ	&#x1D65
LATIN SUBSCRIPT SMALL LETTER X	ₓ	ₓ	&#x2093
GREEK SUBSCRIPT SMALL LETTER BETA	ᵦ	ᵦ	&#x1D66
GREEK SUBSCRIPT SMALL LETTER GAMMA	ᵧ	ᵧ	&#x1D67
GREEK SUBSCRIPT SMALL LETTER RHO	ᵨ	ᵨ	&#x1D68
GREEK SUBSCRIPT SMALL LETTER PHI	ᵩ	ᵩ	&#x1D69
GREEK SUBSCRIPT SMALL LETTER CHI	ᵪ	ᵪ	&#x1D6A

Superscript and Subscript

Check these references for other methods to implement superscript/subscript and extra fractions

Superscript/Subscript in Microsoft Word
Superscript/Subscript in HTML and CSS

Fractions

These codes display fractions set to be all within one line with smaller number, but they can be replaced by other ways of typing a fraction (e.g. "1/2").
-- means no HTML entity code exists and that a numeric code must be used.

Character Name	Character	Entity	Num Entity	Hex Entity
VULGAR FRACTION 1/4	¼	¼	¼	¼
VULGAR FRACTION 1/2	½	½	½	½
VULGAR FRACTION 3/4	¾	¾	¾	¾
VULGAR FRACTION 1/3	⅓	--	⅓	⅓
VULGAR FRACTION 2/3	⅔	--	⅔	⅔
VULGAR FRACTION 1/5	⅕	--	⅕	⅕
VULGAR FRACTION 2/5	⅖	--	₢	⅖
VULGAR FRACTION 3/5	⅗	--	⅗	⅗
VULGAR FRACTION 4/5	⅘	--	⅘	⅘
VULGAR FRACTION 1/6	⅙	--	⅙	⅙
VULGAR FRACTION 5/6	⅚	--	⅚	⅚
VULGAR FRACTION 1/8	⅛	--	⅛	⅛
VULGAR FRACTION 3/8	⅜	--	⅜	⅜
VULGAR FRACTION 5/8	⅝	--	⅝	⅝
VULGAR FRACTION 7/8	⅞	--	ₖ	⅞

Common Statistics

-- means no HTML entity code exists and that a numeric code must be used.

Character Name	Character	Entity	Num Entity	Hex Entity
LOWER CASE MU (Mean)	μ	μ	μ	μ
LOWER CASE SIGMA (Standard Deviation)	σ	σ	σ	σ
LOWER CASE CHI	χ	χ	χ	χ
CAPITAL PI N-ARY PRODUCT	∏	∏	∑	∑
N-ARY COPRODUCT (upside down capital pi)	∐	--	∐	&#x2210

X-Bar, P-Hat and D-Bar

Some codes like that for x̄ (X-bar) are actually a combination of two codes - the base letter x plus a code for the line above (̄: or ̄). Capital letter may need to be reduced in size to accomodate the placement of the combining diacritic.

Note on Safari: These symbols use combining characters and may not be correctly Safari 2 or other older browsers.

Statistical Symbol Codes
Character Name	Character	HTML Code
X-Bar (Average)	x̄	x̄
P-Hat	p̂	p̂
D-Bar	D̄	<span style="font-size:80%">D</span>̄

Measurement Symbols

Common Symbols

Character Name	Character	Entity	Num Entity	Hex Entity
DEGREE SYMBOL	°	°	°	°
MICRO MU SYMBOL	µ	µ	µ	µ
SINGLE PRIME (feet, degree minutes)	′	′	′	߰
DOUBLE PRIME (feet, degree minutes)	″	″转存失败重新上传取消	′	߰
PER MILLE (1/1000th)	‰	&permil;	‰	߮

Calculus

Common Calculus Entity Codes

Character Name	Character	Entity	Num Entity	Hex Entity
INTEGRAL	∫	∫	∫	∫
PARTIAL DIFFERENTIAL	∂	∂	∂	࢚
INCREMENT (Difference or capital Delta)	Δ	Δ	∆	&#x2206
NABLA (Backward Difference, Grad or upside down triangle)	∇	∇	∇	&#x2207

Additional Integral Symbols

These symbols have numeric entity codes only.

Character Name	Character	Num Entity	Hex Entity
DOUBLE INTEGRAL	∬	∬	&#x222C
TRIPLE INTEGRAL	∭	∭	&#x222D
QUADRUPLE INTEGRAL	⨌	⨌	&#x2A0C
CONTOUR INTEGRAL	∮	∮	&#x222E
SURFACE INTEGRAL	∯	∯	&#x222F
VOLUME INTEGRAL	∰	∰	&#x2230
CLOCKWISE INTEGRAL	∱	∱	&#x2231
ANTICCLOCKWISE INTEGRAL	⨑	⨑	&#x2A11
CLOCKWISE CONTOUR INTEGRAL	∲	∲	&#x2232
ANTICLOCKWISE CONTOUR INTEGRAL	∳	∳	&#x2233

Letter Symbols

Character Name	Character	Entity	Num Entity	Hex Entity
INFINITY (Sideways 8)	∞	∞	∞	∞
ALEF INFINITY SYMBOL	ℵ	&alefsym;	ℵ	ℵ
WEIERSTRASS POWER SET (Script Capital P)	℘	&weierp;	℘	℘
IMAGINARY NUMBER (Blackletter I)	ℑ	&image;	′	′
REAL NUMBER (Blackletter I)	ℜ	&real;转存失败重新上传取消	′	′
DOUBLE-STRUCK REAL NUMBER (Double R)	ℝ	--	ℝ	ℝ
COMPLEX NUMBERS (Double C)	ℂ	--	ℂ	ℂ
NATURAL NUMBERS (Double N)	ℕ	--	ℕ	ℕ
PRIME NUMBERS (Double P)	ℙ	--	ℙ	ℙ
RATIONAL NUMBERS (Double Q)	ℚ	--	ℚ	ℚ
INTEGERS (Double Z)	ℤ	--	ℤ	ℤ

Character Name	Character	Entity	Num Entity	Hex Entity
FOR ALL (Upside-down A)	∀	∀	∀	&#x2200
COMPLEMENT (Thin C)	∁	--	∁	&#x2201
THERE EXISTS (Backwards E)	∃	∃	∃	&#x2203
THERE DOES NOT EXIST (Backwards E with slash)	∄	--	∄	&#x2204
EMPTY SET (O slash)	∅	∅	∅	&#x2205
NOT SYMBOL (Corner)	¬	¬	¬	¬
TILDE (Alternate Not Symbol)	˜	&tilde;	--	--
LOGICAL AND (Wedge or Upside down V Symbol)	∧	&and;	∧	&#x2227
LOGICAL OR (V Symbol)	∨	&or;	∨	&#x2228
XOR	⊻	--	⊻	&#x22BB
NAND	⊼	--	⊼	&#x22BC
NOR	⊽	--	⊽	&#x22BD
INTERSECTION (Cap or Upside Down U)	∩	∩	∩	&#x2229
UNION (Cup or U Symbol)	∪	∪	∪	&#x222A
ELEMENT OF	∈	∈	∈	&#x2208
NOT AN ELEMENT OF	∉	∉	∉	&#x2209
SMALL ELEMENT OF	∊	--	∊	&#x220A
CONTAINS AS MEMBER	∋	&ni;	∋	&#x220B
DOES NOT CONTAIN AS MEMBER	∌	--	∌	&#x220C
SMALL CONTAINS AS MEMBER	∍	--	∍	&#x220D
SET MINUS	∖	--	∖	&#x2216
SUBSET OF (Sideways U with cap to left)	⊂	⊂	⊂	&#x2282
SUPERSET OF (Sideways U with cap to right)	⊃	⊃	⊃	&#x2283
NOT A SUBSET OF (Subset with Slash)	⊄	&nsub;	⊄	&#x2284
NOT A SUPERSET OF (Superset with slash)	⊅	--	⊅	&#x2285
SUBSET OF OR EQUAL TO (Subset with line below)	⊆	&sube;	⊆	&#x2286
SUPERSET OF OR EQUAL TO (Superset with line below)	⊇	&supe;	⊇	&#x2287
NEITHER A SUBSET OF NOR EQUAL TO	⊈	--	⊈	&#x2288
NEITHER A SUPERSET OF NOR EQUAL TO	⊉	--	⊉	&#x2289
SUBSET OF WITH NOT EQUAL TO	⊊	--	⊊	&#x228A
SUPERSET OF WITH NOT EQUAL TO	⊋	--	⊋	&#x228B
DIAMOND OPERATOR (Possibility)	⋄	--	⋄	&#x22C4
ASYMPTOTICALLY EQUAL TO One to one Correspondence	≃	--	≃	&#x2243
NOT ASYMPTOTICALLY EQUAL TO	≄	--	≄	&#x2244
MULTISET (U with arrow)	⊌	--	⊌	&#x228C
MULTISET MULTIPLICATION (U with dot in center)	⊍	--	⊍	&#x228D
MULTISET UNION (U with plus in center)	⊎	--	⊎	&#x228E
DOUBLE SUBSET	⋐	--	⋐	&#x22D0
DOUBLE SUPERSET	⋑	--	⋑	&#x22D1
DOUBLE INTERSECTION	⋒	--	⋒	&#x22D2
DOUBLE UNION	⋓	--	⋓	&#x22D3
N-ARY LOGICAL AND	⋀	--	⋀	&#x22C0
N-ARY LOGICAL OR	⋁	--	⋁	&#x22C1
N-ARY INTERSECTION&cu	⋂	--	⋂	&#x22C2
N-ARY UNION	⋃	--	⋃	&#x22C3
CURLY LOGICAL OR	⋎	--	⋎	&#x22CE
CURLY LOGICAL AND	⋏	--	⋏	&#x22CF
CIRCLED PLUS (Direct Sum)	⊕	&oplus;	⊕	&#x2295
CIRCLED TIMES (Vector Product)	⊗	&otimes;	⊗	&#x2297
CIRCLED MINUS	⊖	--	⊖	&#x2296
CIRCLED DIVISION SLASH	⊘	--	⊘	&#x2298

Other Element Of Symbols

ELEMENT OF WITH LONG HORIZONTAL STROKE	⋲	⋲	&#x22F2
ELEMENT OF WITH VERTICAL BAR AT END OF HORIZONTAL STROKE	⋳	⋳	&#x22F3
SMALL ELEMENT OF WITH VERTICAL BAR AT END OF HORIZONTAL STROKE	⋴	⋴	&#x22F4
ELEMENT OF WITH DOT ABOVE	⋵	⋵	&#x22F5
ELEMENT OF WITH OVERBAR	⋶	⋶	&#x22F6
SMALL ELEMENT OF WITH OVERBAR	⋷	⋷	&#x22F7
ELEMENT OF WITH UNDERBAR	⋸	⋸	&#x22F8
ELEMENT OF WITH TWO HORIZONTAL STROKES	⋹	⋹	&#x22F9
CONTAINS WITH LONG HORIZONTAL STROKE	⋺	⋺	&#x22FA
CONTAINS WITH VERTICAL BAR AT END OF HORIZONTAL STROKE	⋻	⋻	&#x22FB
SMALL CONTAINS WITH VERTICAL BAR AT END OF HORIZONTAL STROKE	⋼	⋼	&#x22FC
CONTAINS WITH OVERBAR	⋽	⋽	&#x22FD
SMALL CONTAINS WITH OVERBAR	⋾	⋾	&#x22FE
NOTATION BAG MEMBERSHIP	⋿	⋿	&#x22FF

Geometric Symbols

Note: The entity code for the Angle Symbol (∠) is &ang; and the code for the perpendicular angle (⊥) is&perp;.
Otherwise, these symbols have numeric codes only.

Angles and Lines

Character Name	Character	Num Entity	Hex Entity
RIGHT ANGLE	∟	∟	&#x221F
ANGLE Entity Code = &ang;	∠	∠	&#x2220
MEASURED ANGLE	∡	∡	&#x2221
SPHERICAL ANGLE	∢	∢	&#x2222
DIVIDES	∣	∣	&#x2223
DOES NOT DIVIDE	∤	∤	&#x2224
PARALLEL TO	∥	∥	&#x2225
NOT PARALLEL TO	∦	∦	&#x2226
RIGHT ANGLE WITH ARC	⊾	⊾	&#x22BE
RIGHT TRIANGLE	⊿	⊿	&#x22BF
UP TACK (Perpendicular) Entity Code = &perp;	⊥	⊥	&#x22A5
RIGHT TACK	⊢	⊢	&#x22A2
LEFT TACK	⊣	⊣	&#x22A3
DOWN TACK	⊤	⊤	&#x22A4

Logical Proofs

Note: The entity code for the Therefore Symbol (∴) is &there4;. Otherwise, these symbols have numeric codes only.

Character Name	Character	Num Entity	Hex Entity
THEREFORE (Triangular Dots) Entity Code = &there4;	∴	∴	∴
BECAUSE (Upside down Triangular Dots)	∵	∵	&#x2235
PROPORTIONAL TO Entity Code = &prop;	∝	∝	&#x221D
END OF PROOF (solid rectangle)	∎	∎	&#x220E

Common Equivalence and Proportion Operators

Common Equivalence Operators

Character Name	Character	Entity	Num Entity	Hex Entity
NOT EQUALS	≠	≠	≠	≠
APPROXIMATELY EQUAL	≅	&cong;	≅	≅
ALMOST EQUAL (ASYMPTOTIC)	≈	≈	≈	≈
NOT ALMOST EQUAL TO	≉	--	≉	&#x2249
TILDE SIMILAR TO	∼	&sim;	∼	∼
IDENTICAL TO (three lines)	≡	&equiv;	≡	≡
NOT IDENTICAL TO	≢	--	≢	&#x2262

Other Equivalence Symbols

STRICTLY EQUIVALENT TO	≣	≣	&#x2263
NOT IDENTICAL TO	≢	≢	&#x2262
LESS-THAN OVER EQUAL TO	≦	≦	&#x2266
GREATER-THAN OVER EQUAL TO	≧	≧	&#x2267
LESS-THAN BUT NOT EQUAL TO	≨	≨	&#x2268
GREATER-THAN BUT NOT EQUAL TO	≩	≩	&#x2269
MUCH LESS-THAN	≪	≪	&#x226A
MUCH GREATER-THAN	≫	≫	&#x226B
BETWEEN	≬	≬	&#x226C
NOT EQUIVALENT TO	≭	≭	&#x226D
NOT LESS-THAN	≮	≮	&#x226E
NOT GREATER-THAN	≯	≯	&#x226F
NEITHER LESS-THAN NOR EQUAL TO	≰	≰	&#x2270
NEITHER GREATER-THAN NOR EQUAL TO	≱	≱	&#x2271
LESS-THAN OR EQUIVALENT TO	≲	≲	&#x2272
GREATER-THAN OR EQUIVALENT TO	≳	≳	&#x2273
NEITHER LESS-THAN NOR EQUIVALENT TO	≴	≴	&#x2274
NEITHER GREATER-THAN NOR EQUIVALENT TO	≵	≵	&#x2275
LESS-THAN OR GREATER-THAN	≶	≶	&#x2276
GREATER-THAN OR LESS-THAN	≷	≷	&#x2277
NEITHER LESS-THAN NOR GREATERTHAN	≸	≸	&#x2278
NEITHER GREATER-THAN NOR LESSTHAN	≹	≹	&#x2279
NOT TILDE	≁	≁	&#x2241
MINUS TILDE	≂	≂	&#x2242
ASYMPTOTICALLY EQUAL TO	≃	≃	&#x2243
NOT ASYMPTOTICALLY EQUAL TO	≄	≄	&#x2244
APPROXIMATELY BUT NOT ACTUALLY EQUAL TO	≆	≆	&#x2246
NEITHER APPROXIMATELY NOR ACTUALLY EQUAL TO	≇	≇	&#x2247
NOT ALMOST EQUAL TO	≉	≉	&#x2249
ALMOST EQUAL OR EQUAL TO	≊	≊	&#x224A
TRIPLE TILDE	≋	≋	&#x224B
ALL EQUAL TO	≌	≌	&#x224C