Delphi XE8 TStringHelper用法详解
capelin 发布 | 2015-5-29 | 评论数:0 | 阅读数:3995 | 标签:
System.SysUtils.TStringHelper 大小写转换: -------------------------------------------------------------------------------- function ToLower: string; function ToLower(LocaleID: TLocaleID): string; function ToLowerInvariant: string; function ToUpper: string; function ToUpper(LocaleID: TLocaleID): string; function ToUpperInvariant: string; class function LowerCase(const S: string): string; class function LowerCase(const S: string; LocaleOptions: TLocaleOptions): string; class function UpperCase(const S: string): string; class function UpperCase(const S: string; LocaleOptions: TLocaleOptions): string; //-------------------------------------------------------------------------------- var str: string; begin str := 'Delphi'; str := str.ToLower; // delphi str := str.ToUpper; // DELPHI end; -------------------------------------------------------------------------------- 清除两边空格或指定字符: -------------------------------------------------------------------------------- function Trim: string; function TrimLeft: string; function TrimRight: string; function Trim(const TrimChars: array of Char): string; function TrimLeft(const TrimChars: array of Char): string; function TrimRight(const TrimChars: array of Char): string; //-------------------------------------------------------------------------------- var str1, str2: string; begin str1 := ' Delphi 10000 '; str2 := str1.TrimLeft; // 'Delphi 10000 ' str2 := str1.TrimRight; // ' Delphi 10000' str2 := str1.Trim; // 'Delphi 10000' str2 := str1.Trim([' ', '0']); // 'Delphi 1' end; -------------------------------------------------------------------------------- 字符串对比: -------------------------------------------------------------------------------- function CompareTo(const strB: string): Integer; class function Compare(const StrA: string; const StrB: string): Integer; class function CompareText(const StrA: string; const StrB: string): Integer; class function Compare(const StrA: string; const StrB: string; LocaleID: TLocaleID): Integer; class function Compare(const StrA: string; const StrB: string; IgnoreCase: Boolean): Integer; class function Compare(const StrA: string; const StrB: string; IgnoreCase: Boolean; LocaleID: TLocaleID): Integer; class function Compare(const StrA: string; IndexA: Integer; const StrB: string; IndexB: Integer; Length: Integer): Integer; class function Compare(const StrA: string; IndexA: Integer; const StrB: string; IndexB: Integer; Length: Integer; LocaleID: TLocaleID): Integer; class function Compare(const StrA: string; IndexA: Integer; const StrB: string; IndexB: Integer; Length: Integer; IgnoreCase: Boolean): Integer; class function Compare(const StrA: string; IndexA: Integer; const StrB: string; IndexB: Integer; Length: Integer; IgnoreCase: Boolean; LocaleID: TLocaleID): Integer; class function CompareOrdinal(const StrA: string; const StrB: string): Integer; class function CompareOrdinal(const StrA: string; IndexA: Integer; const StrB: string; IndexB: Integer; Length: Integer): Integer; //-------------------------------------------------------------------------------- var str1, str2: string; n: Integer; begin str1 := 'ABC 123'; str2 := 'abc 123'; n := str1.CompareTo(str2); // -32 n := str1.Compare(str1, str2); // 1 n := str1.CompareText(str1, str2); // 0; 相同 n := str1.Compare(str1, str2, True); // 0; 不区分大小写 n := str1.CompareOrdinal(str1, str2); // -32 n := str1.Compare(str1, 4, str2, 4, 3); // 0; 只对比后三位 end; -------------------------------------------------------------------------------- 搜索字符串: -------------------------------------------------------------------------------- function IndexOf(value: Char): Integer; function IndexOf(const Value: string): Integer; function IndexOf(Value: Char; StartIndex: Integer): Integer; function IndexOf(const Value: string; StartIndex: Integer): Integer; function IndexOf(Value: Char; StartIndex: Integer; Count: Integer): Integer; function IndexOf(const Value: string; StartIndex: Integer; Count: Integer): Integer; function IndexOfAny(const AnyOf: array of Char): Integer; function IndexOfAny(const AnyOf: array of Char; StartIndex: Integer): Integer; function IndexOfAny(const AnyOf: array of Char; StartIndex: Integer; Count: Integer): Integer; function LastIndexOf(Value: Char): Integer; function LastIndexOf(const Value: string): Integer; function LastIndexOf(Value: Char; StartIndex: Integer): Integer; function LastIndexOf(const Value: string; StartIndex: Integer): Integer; function LastIndexOf(Value: Char; StartIndex: Integer; Count: Integer): Integer; function LastIndexOf(const Value: string; StartIndex: Integer; Count: Integer): Integer; function LastIndexOfAny(const AnyOf: array of Char): Integer; function LastIndexOfAny(const AnyOf: array of Char; StartIndex: Integer): Integer; function LastIndexOfAny(const AnyOf: array of Char; StartIndex: Integer; Count: Integer): Integer; //-------------------------------------------------------------------------------- var str: string; n: Integer; begin str := 'A1 A2 A3 A4'; n := str.IndexOf('A'); // 0 n := str.LastIndexOf('A'); // 9 n := str.IndexOf('B'); // -1; 没找到 n := str.IndexOf('A', 1, str.Length - 1); // 3 n := str.LastIndexOf('A', str.Length - 1, str.Length - 1); // 9 n := str.IndexOfAny(['1', '2', '3', '4']); // 1 n := str.LastIndexOfAny(['1', '2', '3', '4']); // 10 end; -------------------------------------------------------------------------------- 是否包含: -------------------------------------------------------------------------------- function Contains(const Value: string): Boolean; function StartsWith(const Value: string): Boolean; function StartsWith(const Value: string; IgnoreCase: Boolean): Boolean; function EndsWith(const Value: string): Boolean; function EndsWith(const Value: string; IgnoreCase: Boolean): Boolean; class function EndsText(const ASubText, AText: string): Boolean; //-------------------------------------------------------------------------------- var str: string; b: Boolean; begin str := 'Delphi XE4'; b := str.Contains('XE'); // True b := str.Contains('xe'); // False b := str.StartsWith('delphi'); // False b := str.StartsWith('delphi', True); // True b := str.EndsWith('XE4'); // True b := str.EndsText('xe4', str); // True end; -------------------------------------------------------------------------------- 添加或解除引号: -------------------------------------------------------------------------------- function QuotedString: string; function QuotedString(const QuoteChar: Char): string; function DeQuotedString: string; function DeQuotedString(const QuoteChar: Char): string; //-------------------------------------------------------------------------------- var str1, str2: string; begin str1 := 'Delphi'; str2 := str1.QuotedString; // 'Delphi' str2 := str1.QuotedString('"'); // "Delphi" str1 := '"Delphi"'; str2 := str1.DeQuotedString('"'); // Delphi end; -------------------------------------------------------------------------------- 适宽处理: -------------------------------------------------------------------------------- function PadLeft(TotalWidth: Integer): string; function PadLeft(TotalWidth: Integer; PaddingChar: Char): string; function PadRight(TotalWidth: Integer): string; function PadRight(TotalWidth: Integer; PaddingChar: Char): string; //-------------------------------------------------------------------------------- var str: string; begin str := '1'; str := str.PadLeft(4, '0'); // 0001 end; -------------------------------------------------------------------------------- 插入与删除: -------------------------------------------------------------------------------- function Insert(StartIndex: Integer; const Value: string): string; function Remove(StartIndex: Integer): string; function Remove(StartIndex: Integer; Count: Integer): string; //-------------------------------------------------------------------------------- var str1, str2: string; begin str1 := 'Delphi 4'; str2 := str1.Insert(7, 'XE'); // Delphi XE4 str1 := 'Delphi XE4'; str2 := str1.Remove(6); // Delphi str2 := str1.Remove(7, 2); // Delphi 4 end; -------------------------------------------------------------------------------- 截取: -------------------------------------------------------------------------------- function Substring(StartIndex: Integer): string; function Substring(StartIndex: Integer; Length: Integer): string; //-------------------------------------------------------------------------------- var str1, str2: string; begin str1 := 'Delphi XE4'; str2 := str1.Substring(7); // XE4 str2 := str1.Substring(7, 2); // XE end; -------------------------------------------------------------------------------- 替换: -------------------------------------------------------------------------------- function Replace(OldChar: Char; NewChar: Char): string; function Replace(OldChar: Char; NewChar: Char; ReplaceFlags: TReplaceFlags): string; function Replace(const OldValue: string; const NewValue: string): string; function Replace(const OldValue: string; const NewValue: string; ReplaceFlags: TReplaceFlags): string; //-------------------------------------------------------------------------------- var str1, str2: string; begin str1 := 'ABC ABC ABC'; str2 := str1.Replace('A', '*'); // *BC *BC *BC str2 := str1.Replace('A', '*', [rfIgnoreCase]); // *BC ABC ABC end; -------------------------------------------------------------------------------- 分割: -------------------------------------------------------------------------------- function Split(const Separator: array of Char): TArray; function Split(const Separator: array of Char; Count: Integer): TArray; function Split(const Separator: array of Char; Options: TStringSplitOptions): TArray; function Split(const Separator: array of string; Options: TStringSplitOptions): TArray; function Split(const Separator: array of Char; Count: Integer; Options: TStringSplitOptions): TArray; function Split(const Separator: array of string; Count: Integer; Options: TStringSplitOptions): TArray; //-------------------------------------------------------------------------------- var str: string; arr: TArray; begin str := 'A-1,B-2,,,C-3,D-4'; arr := str.Split([',']); // arr[0] = A-1; Length(arr) = 6 arr := str.Split([','], TStringSplitOptions.ExcludeEmpty); // 忽略空项; Length(arr) = 4 arr := str.Split([','], 2); // 只提取前 2 arr := str.Split([',', '-'], ExcludeEmpty); //arr[0] = A; Length(arr) = 8 arr := str.Split([',,,'], None); // 分隔符可以是一个字符串数组 end; -------------------------------------------------------------------------------- 连接: -------------------------------------------------------------------------------- class function Join(const Separator: string; const values: array of const): string; class function Join(const Separator: string; const Values: array of string): string; class function Join(const Separator: string; const Values: IEnumerator): string; class function Join(const Separator: string; const Values: IEnumerable): string; class function Join(const Separator: string; const value: array of string; StartIndex: Integer; Count: Integer): string; //-------------------------------------------------------------------------------- var S: string; str: string; strArr: TArray; begin str := 'A1,B2,C3,,,,D4,E5,F6,G7'; strArr := str.Split([','], ExcludeEmpty); str := S.Join('-', strArr); // A1-B2-C3-D4-E5-F6-G7 str := S.Join('; ', [1,2,3,4,5]); // 1; 2; 3; 4; 5 str := S.Join(',', ['abc', 123, true]); // abc,123,True end; -------------------------------------------------------------------------------- 类型转换: -------------------------------------------------------------------------------- function ToBoolean: Boolean; function ToInteger: Integer; function ToSingle: Single; function ToDouble: Double; function ToExtended: Extended; class function ToBoolean(const S: string): Boolean; class function ToInteger(const S: string): Integer; class function ToSingle(const S: string): Single; class function ToDouble(const S: string): Double; class function ToExtended(const S: string): Extended; class function Parse(const Value: Integer): string; class function Parse(const Value: Int64): string; class function Parse(const Value: Boolean): string; class function Parse(const Value: Extended): string; //-------------------------------------------------------------------------------- var S: string; str: string; n: Integer; b: Boolean; f: Double; begin str := S.Parse(123); n := str.ToInteger; // 123 b := str.ToBoolean; // True str := S.Parse(True); b := str.ToBoolean; // True n := str.ToInteger; // -1 str := S.Parse(3.14159260000); f := str.ToDouble; //3.1415926 end; -------------------------------------------------------------------------------- 定界符: -------------------------------------------------------------------------------- function IsDelimiter(const Delimiters: string; Index: Integer): Boolean; function LastDelimiter(const Delims: string): Integer; //-------------------------------------------------------------------------------- var str: string; b: Boolean; n: Integer; begin str := 'http://del.cnblogs.com'; b := str.IsDelimiter(':', 4); // True b := str.IsDelimiter('//', 5); // True n := str.LastDelimiter('.'); // 18 n := str.IndexOf('.'); // 10 end; -------------------------------------------------------------------------------- 空字符串: -------------------------------------------------------------------------------- const Empty = ''; function IsEmpty: Boolean; class function IsNullOrEmpty(const Value: string): Boolean; class function IsNullOrWhiteSpace(const Value: string): Boolean; //-------------------------------------------------------------------------------- var S: string; str: string; b: Boolean; begin str := ' '; b := str.IsEmpty; // False b := S.IsNullOrWhiteSpace(str); // True end; -------------------------------------------------------------------------------- String 与 Char: -------------------------------------------------------------------------------- class function Create(C: Char; Count: Integer): string; class function Create(const Value: array of Char; StartIndex: Integer; Length: Integer): string; class function Create(const Value: array of Char): string; property Chars[Index: Integer]: Char read GetChars; property Length: Integer read GetLength; function CountChar(const C: Char): Integer; function ToCharArray: TArray; function ToCharArray(StartIndex: Integer; Length: Integer): TArray; procedure CopyTo(SourceIndex: Integer; var destination: array of Char; DestinationIndex: Integer; Count: Integer); //-------------------------------------------------------------------------------- var S: string; str, str2: string; charArr: TCharArray; n: Integer; c: Char; begin str := 'ABC'; n := str.Length; // 3 c := str.Chars[0]; // A = str[1] str := S.Create('A', 7); // AAAAAAA charArr := 'ABCDEFG'.ToCharArray; str := s.Create(charArr); // ABCDEFG str := S.Create(charArr, 1, 3); // BCD charArr := '1234567890'.ToCharArray; str := 'ABCDEFG'; str.CopyTo(1, charArr, 2, 3); str := S.Create(charArr); // 12BCD67890 end; -------------------------------------------------------------------------------- 其他: -------------------------------------------------------------------------------- function Equals(const Value: string): Boolean; function GetHashCode: Integer; class function Equals(const a: string; const b: string): Boolean; class function Format(const Format: string; const args: array of const): string; class function Copy(const Str: string): string; //-------------------------------------------------------------------------------- // 用 Equals 不如直接用 = 号 // 用 Copy 不如直接用 := // 用 string.Format 不如直接用 Format() // 总之, 还是有用处的多!
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