AnsiString用法（转）

源：AnsiString用法

//Ansistring 转 char
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "哈哈";
    char *chr = Test.c_str();
} 

//char转Ansistring
#include <windef.h>
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString str = "Sample";
    char chr[MAX_PATH];
    strcpy( chr , str.c_str() );
} 

//Bool转AnsiString
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test=BoolToStr(CheckBox1->Checked);
} 

//Ansistring转bool
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test="-1"
    CheckBox1->Checked= StrToBool( Test );
} 

//int转ansistring
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    int i = ;
    AnsiString str = IntToStr( i );
} 

//AnsiString转double
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "";
    long double d = StrToFloat( Test );
} 

//double转AnsiString
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    double d = 123.456;
    AnsiString str = FloatToStr( d );
} 

//double转AnsiString并四舍五入
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    long double d = 123.456121212;
    AnsiString str = FloatToStrF( d , ffFixed , ,  );
//说明FloatTostrF里5代表从第几个数字的后一位开始四舍五入,4代表取4位小数。
//执行后得到str是123.4600。:roll: 

} 

//double转AnsiString使用类似vb的format函数
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    double d = 123.456;
    AnsiString str = FormatFloat( "000000.00" , d );
}
//得到 000123.45，当然你可以使用"# . , ; E+ E- xx"等符号，你自己试试 :wink: 

//AnsiString转Tclor型
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "0x00FF8080";
    TColor Col = StringToColor( Test );
} 

//Tcolor转AnsiString
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    TColor Col = 0x00FF8080;
    AnsiString str = ColorToString( Col );
} 

//消除AnsiString 中的一部分字符串 代码:
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "ABCDEF";
    int First = ;     // 消除制定开头
    int Length = ;    // 消除制定长度
    AnsiString Dstr = Test.Delete( First , Length );
}//得到ABEF 

//在AnsiString 中插入字符串
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "ABCDEF";
    AnsiString Ins = "";     // 插入串
    int Pos = ;                  // 在哪插
    AnsiString Istr = Test.Insert( Ins , Pos );
//得到AB12345CDEF
} 

//取得ansi某一位字符
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "ABCDEF";
    AnsiString Npos = Test[];//得到C
} 

//取得AnsiString里最后一个字符
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "ABCDEF";
    char *Lstr = Test.AnsiLastChar();//得到F
} 

//取出AnsiString字符，这个类似vb的mid函数！
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "ABCDEF";
    int First = ;     // 3开始取
    int Length = ;    // 取2位
    AnsiString Getstr = Test.SubString( First , Length );
//得到CD
} 

//AnsiString的字母比较
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "ABCDEF";
    AnsiString Sample = "abcdef";
    int Result = Test.AnsiCompare( Sample );
//返回1，不同！分大小写。
} 

void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "ABCDEF";
    AnsiString Sample = "abcdef";
    int Result = Test.AnsiCompareIC( Sample );
//返回0，相同！没有分大小写，哈哈
} 

//在AnsiString中寻找字符
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "ABCDEF";
    AnsiString Sample = "E";
    int Result = Test.Pos( Sample );
//返回5，如果你写Sample＝"haha",就返回0，找不到，哈哈
} 

//在AnsiString中找字符串，和上一个类似
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "ABCDEF";
    AnsiString Sample = "EF";
    int Result = Test.Pos( Sample );
//返回5，即E字符的位置
} 

//判断字符串长度，类似vb的len
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "拿金币来";
    int Len = Test.Length();
//返回8
} 

//取得字符串，类似vb的left
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "小苹果然看了这篇文章";
    AnsiString SLstr = Test.SetLength();
}//得到"小苹果" 

//检测双字节字串
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString ChkStr = "你好";
    int ChkPos =    ;
    if ( ByteType( ChkStr , ChkPos ) == mbSingleByte ){
        Edit1->Text="";
    }
    else{
        Edit1->Text="";
    }//返回1，如果你写ChkStr＝"fxxk"，就返回0
} 

//检测空字符串
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "";
    bool chk = Test.IsEmpty();
    if (chk )
        Edit1->Text="";//返回1
} 

//全部变小写vs全部变大写
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "ABCdef";
    AnsiString Lstr = Test.LowerCase();
} 

代码: 

void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "ABCdef";
    AnsiString Ustr = Test.UpperCase();
} 

//类似vb中Trim 的去空格函数
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "     ABCDEF      ";
    AnsiString TLstr = Test.TrimLeft();
    AnsiString TRstr = Test.TrimRight();
    AnsiString Tstr = Test.Trim();
} 

//但是，这个处理不了全角的空格 代码:
AnsiString __fastcall TForm1::TrimStr( AnsiString Tm , AnsiString LR )
{
    // LR … L:左除去   R:右除去   B:dou除去
    int len;
    // 左除去
    if ( LR == "L" || LR == "B" ){
        len = Tm.Length();
        while ( Tm.SubString(,) == " " || Tm.SubString(,) == "　"){
            // 半角除去
            if ( Tm.SubString(,) == " " ){
                Tm = Tm.SubString(,len);
                len = Tm.Length();
            }
            // 全角除去
            else if ( Tm.SubString(,) == "　" ){
                Tm = Tm.SubString(,len);
                len = Tm.Length();
            }
        }
    }
    // 右除去
    if ( LR == "R" || LR == "B" ){
        len = Tm.Length();
        while ( Tm.SubString(len,) == " " || Tm.SubString(len-,) == "　" ){
            // 半角除去
            if ( Tm.SubString(len,) == " " ){
                len = Tm.Length();
                Tm = Tm.SubString(,len-);
                len = Tm.Length();
            }
            // 全角除去
            else if ( Tm.SubString(len-,) == "　" ){
                len = Tm.Length();
                Tm = Tm.SubString(,len-);
                len = Tm.Length();
            }
        }
    }
    return Tm;
}
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "　　拳脚　　";
    AnsiString Ret = TrimStr(Test,"B")
} 

//相同字符重复输入
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Soc = AnsiString::StringOfChar( '*' ,  );
   Edit1->Text=Soc ;//显示100个* 

} 

//字符串替换
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Str = "Borland C++ Builder is free";
    AnsiString From = "C++ Builder";
    AnsiString To = "Delphi";
    AnsiString Result;
    Result = StringReplace( Str, From, To, TReplaceFlags() <<
rfReplaceAll << rfIgnoreCase );
//<<后是参数，得到Borland Delphi is free
} 

//全角变半角
    AnsiString Zen = "１２３４５６７８９０";
    int Len = Zen.Length();
    char buf[MAX_PATH];
    ZeroMemory( buf, sizeof( buf ) );
    LCMapString( GetUserDefaultLCID(), LCMAP_HALFWIDTH, Zen.c_str(), Len, buf, sizeof( buf ) );
    AnsiString Han = AnsiString( buf );
    Edit1->Text=Han; 

//半角变全角
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Han = "";
    int Len = Han.Length();
    char buf[MAX_PATH];
    ZeroMemory( buf, sizeof( buf ) );
    LCMapString( GetUserDefaultLCID(), LCMAP_FULLWIDTH, Han.c_str(), Len, buf, sizeof( buf ) );
    AnsiString Zen = AnsiString( buf );
}