C++ builder(BCB) Ansistring(字元、字串、數字等互轉+常用運算)

資料來源:http://blog.xuite.net/apo.chen/blog/38803287

AnsiString 轉 char

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

   

char轉AnsiString

void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString str = "Sample";
    char chr[MAX_PATH];
    strcpy( chr , str.c_str() );
}

 

Bool轉AnsiString

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

 

AnsiString轉bool

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

 

int轉AnsiString

void __fastcall TForm1::Button1Click(TObject *Sender)
{
    int i = 123;
    AnsiString str = IntToStr( i );
}

 

AnsiString轉double

void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "123";
    long double d = StrToFloat( Test );
}

 

double轉AnsiString

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

 

 

double轉AnsiString並四捨五入

void __fastcall TForm1::Button1Click(TObject *Sender)
{
    long double d = 123.456121212;
    AnsiString str = FloatToStrF( d , ffFixed ,5 , 4 );
    //說明FloatTostrF裏5代表從第幾個數字的後一位元開始四捨五入,4代表取4位小數。
    //執行後得到str是123.4600。:roll:
}

 

double轉AnsiString使用類似vb的format函數

void __fastcall TForm1::Button1Click(TObject *Sender)
{
    double d = 123.456;
    AnsiString str = FormatFloat( "000000.00" , d );
}
//得到 000123.45，當然你可以使用"# . , ; E+ E- xx"等符號，你自己試試 😉
 

AnsiString轉Tclor型

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

Tclor轉AnsiString

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

消除AnsiString 中的一部分字串代碼:

void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "ABCDEF";
    int First = 3;     // 消除制定開頭
    int Length = 2;    // 消除制定長度
    AnsiString Dstr = Test.Delete( First , Length );
}//得到ABEF

 

在AnsiString 中插入字串

void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "ABCDEF";
    AnsiString Ins = "12345";     // 插入串
    int Pos = 3;                  // 在哪插
    AnsiString Istr = Test.Insert( Ins , Pos );
    //得到AB12345CDEF
}

取得ansi某一位元字元

void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "ABCDEF";
    AnsiString Npos = Test[3];//得到C
}

取得AnsiString裏最後一個字元

void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "ABCDEF";
    char *Lstr = Test.AnsiLastChar();//得到F
}

取出AnsiString字元，這個類似vb的mid函數！

void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "ABCDEF";
    int First = 3;     // 3開始取


    int Length = 2;    // 取2位
    AnsiString Getstr = Test.SubString( First , Length );
//得到CD
}

AnsiString的字母比較

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

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

在AnsiString中尋找字元

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

在AnsiString中找字串，和上一個類似

void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "ABCDEF";
    AnsiString Sample = "EF";
    int Result = Test.Pos( Sample );
//返回5，即E字元的位置
}

判斷字串長度，類似vb的len

void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "拿金幣來";
    int Len = Test.Length();
//返回8
}

取得字串，類似vb的left(字串切割/截斷)

代碼:

void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "小蘋果然看了這篇文章";
    AnsiString SLstr = Test.SetLength(6);
}//得到“小蘋果”

 

檢測雙位元組字串

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

檢測空字串

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

全部變小寫vs全部變大寫

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



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

類似vb中Trim 的去除字串中空格函數

void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "     ABCDEF      ";
    AnsiString TLstr = Test.TrimLeft();
   AnsiString TRstr = Test.TrimRight();
  AnsiString Tstr = Test.Trim();
}

 

去除字串中全形的空格 代碼:

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(1,1) == " " || Tm.SubString(1,2) == "　"){
            // 半形除去
            if ( Tm.SubString(1,1) == " " ){
                Tm = Tm.SubString(2,len);


                len = Tm.Length();
            }
            // 全形除去
            else if ( Tm.SubString(1,2) == "　" ){
                Tm = Tm.SubString(3,len);
                len = Tm.Length();
            }
        }
    }
    // 右除去
    if ( LR == "R" || LR == "B" ){
        len = Tm.Length();
        while ( Tm.SubString(len,1) == " " || Tm.SubString(len-1,2) == "　" ){
            // 半形除去
            if ( Tm.SubString(len,1) == " " ){
                len = Tm.Length();
                Tm = Tm.SubString(1,len-1);
                len = Tm.Length();
            }
            // 全形除去
            else if ( Tm.SubString(len-1,2) == "　" ){
                len = Tm.Length();
                Tm = Tm.SubString(1,len-2);
                len = Tm.Length();
            }
        }
    }
    return Tm;
}
void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Test = "　　拳腳　　";
    AnsiString Ret = TrimStr(Test,"B")
}

 

相同字元重複輸入

void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Soc = AnsiString::StringOfChar( '*' , 100 );
   Edit1->Text=Soc ;//顯示100個*

}

字串替換/取代

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 );
//<<後是參數，得到Borland Delphi is free
}

全形字串轉半形字串

    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;

 

半形字串轉全形字串

void __fastcall TForm1::Button1Click(TObject *Sender)
{
    AnsiString Han = "1234567890";
    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 );
}

 

AnsiString重載了“[]”運算符，可以將內容當做字元陣列一樣操作，不過和char[]不同的是AnsiString的[]運算符的下標是從1 開始的，和Delphi的String 相容。對於長度不大的AnsiString可以直接使用[]來操作，長度大的時候最好轉換成char*在使用，因為重載是通過成員函數實現的，增加了系統的調用開銷。
如：

AnsiString  Temp = "這是一個測試的AnsiString";
int Length = Temp.Length();
for(int i = 1; i <= Length;i++)
{
    if(Temp[i] > 128)
    {
         //........
         //篩選其中的漢字;
         i++;
    }
    else
    {
         //......非漢字的字元。
    }
}

AnsiString的構造函數有以下幾種：[各種 變數形態 直接轉字串的方法]

__fastcall AnsiString();
__fastcall AnsiString(const char* src);
__fastcall AnsiString(const AnsiString& src);
__fastcall AnsiString(const char* src, unsigned char len);
__fastcall AnsiString(const wchar_t* src);
__fastcall AnsiString(int src);
__fastcall AnsiString(double src);

__fastcall AnsiString(char src);
__fastcall AnsiString(short);
__fastcall AnsiString(unsigned short);
__fastcall AnsiString(unsigned int);
__fastcall AnsiString(long);
__fastcall AnsiString(unsigned long);
__fastcall AnsiString(__int64);
__fastcall AnsiString(unsigned __int64);
__fastcall AnsiString(const WideString &src);