[原创]Delphi中ScriptControl的高级应用（二）[4]

        c3 = str.charcodeat(i++) & 0xff;

        if(c3 == 61)

        return out;

        c3 = base64decodechars[c3];

    } while(i < len && c3 == -1);

    if(c3 == -1)

        break;

    out += string.fromcharcode(((c2 & 0xf) << 4) | ((c3 & 0x3c) >> 2));

    /* c4 */

    do {

        c4 = str.charcodeat(i++) & 0xff;

        if(c4 == 61)

        return out;

        c4 = base64decodechars[c4];

    } while(i < len && c4 == -1);

    if(c4 == -1)

        break;

    out += string.fromcharcode(((c3 & 0x03) << 6) | c4);

    }