☰

正确的 if 语句

tag-icon • tag-icon conditionals ifthenelse
正确的 if 语句

我真的很难让 if 语句正常工作....下面是包含所需所有代码的 zip 文件的链接：https://www.dropbox.com/s/ojsj33oe9ac4g09/latex-rechnung.zip?dl=0

我的代码：

\documentclass[a4paper]{scrlttr2}    
\usepackage[top=2cm, bottom=2cm, left=2cm, right=2cm]{geometry}
\usepackage{graphicx}
\usepackage{lmodern}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[ngerman]{babel}
\usepackage{color}
\usepackage[hidelinks]{hyperref}
\usepackage{lipsum}
\usepackage{xifthen}

\usepackage[german]{invoice}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\makeatletter
\def\UnitDay{Preis/Tag}% <========================================

\newcommand{\FeeDay@Title}{% <==========================================
    \\
    \noindent\textbf{\Activity}&&\UnitDay&\Count&\Amount\ (\BC)\\
    \hline%
}%

\newcommand{\FeeDay}[3]{% Yields state 3, Print Fee Item <==============
    %
    % #1 Contents
    % #2 Fee per Day
    % #3 Unit Count
    %
    \ifcase\Flag % 0: Invoice not started yet
        \error@message{\MissingOpening}%
        %
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \or % 1: Start invoice
        %
        \error@message{\MissingProject}%
        %
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \or % 2: Start project, print title
        %
        \FeeDay@Title%
        \Fee@Line{#1}{#2}{#3}%
        %
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \or % 3: Print remuneration item
        %
        \Fee@Line{#1}{#2}{#3}%
        %
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \or % 4: Print subtotal remuneration
        %
        \warning@message{\FeeSTExists}%
        %
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \or % 5: Expense item
        %
        \error@message{\FeeBeforeExpense}%
        %
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \or % 6: Print subtotal expenses
        %
        \error@message{\FeeBeforeExpense}%
        %
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \or % 7: Print subtotal project
        %
        \error@message{\ProjectCompletedNoFee}%
        %
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \or % 8: Print total, close invoice
        %
        \error@message{\InvoiceCompletedNoFee}%
        %
        %
    \else \error@message{\InternalError}%
    \fi%
}%
\makeatother


\renewcommand{\familydefault}{\sfdefault}

% include meta data
\include{_data} % <============== delete in this file the following data!
% ################## invoice DATA ##################
\newcommand{\invoiceDate}{\today} % Datum der rechnungsstellung
\newcommand{\invoiceReference}{2019\_02\_04\_1} % Rechnungsnummer (z.B. 20150122-4) YYYYMMDD-1
\newcommand{\invoiceSalutation}{} % die Anrede
\newcommand{\invoiceText}{Folgende Positionen werden in Rechnung gestellt:} % Rechnungstext
\newcommand{\invoiceEnclosures}{} % \encl{} einfügen
\newcommand{\invoiceClosing}{Mit freundlichen Grüßen}
% ################## invoice DATA ##################


% ##################Job DATA ####################
\def \performaceStart {14.01.2019}
\def \performaceEnd {01.02.2019}
% ##################Job DATA ####################


% ################## Customer DATA ##################
\newcommand{\customerCompany}{Firma ABC} %ggf. Firma
\newcommand{\customerName}{Mustermann} % Name
\newcommand{\customerStreet}{Straße 123} % Straße
\newcommand{\customerZIP}{12345} % Postleitzahl
\newcommand{\customerCity}{Musterstadt} % Ort
\newcommand{\customerNumber}{1000} % Kundennummer <==================
% ################## Customer DATA ##################

\setkomavar{fromname}{\senderName}
\setkomavar{fromaddress}{\senderStreet \\ \senderZIP \ \senderCity}
\setkomavar{place}{\senderCity}
\setkomavar{date}{\invoiceDate}
\setkomavar{fromphone}{\senderTelephone}
\setkomavar{frommobilephone}{\senderMobilephone}
\setkomavar{fromemail}{\href{mailto:\senderEmail}{\nolinkurl{\senderEmail}}}
\setkomavar{subject}{Rechnung}

\def \invoicenr{Rechnungsnummer: }% <========================================
\def \customernr{Kundennummer: }%
\def \performanceDuration{Leistungszeitraum: }

\setkomavar{location}{\vspace*{-1.99cm}
      \\[\baselineskip] \\[\baselineskip]
      \flushright\small \invoicenr \invoiceReference\\[5pt]
      \customernr\\
      \customerNumber\\[5pt]
      \performanceDuration\\

      \newcommand{\downow}{
    \if \performanceEnd == {}
        \performaceStart{} -- \performaceEnd
    \else
        \performanceStart
      }
    %      \performaceStart{} -- \performaceEnd
    }


\setkomavar{firsthead}{\hfill
   \parbox[t][\headheight][t]{7.3cm}
   {% 
   \footnotesize
   \raggedright
   \flushright
   \color[gray]{.3}%               
   }%
}


\begin{document}
    \begin{letter}{\customerCompany \\ \customerName \\ 
    \customerStreet \\ \customerZIP \ \customerCity}\vspace*{-3.5cm}


            \opening{\invoiceSalutation}
            \invoiceText
            \begin{invoice}{Euro}{0}

\ProjectTitle{Tagesleistungen} % 
\FeeDay{Freelancing}    {300}       {1}

%\ProjectTitle{Projekttitel} % 
%\Fee{Überstunden}          {37.5}  {4}



% Auslagen
%\EBC{Softwarenutzung} {150.00} 
%\EBCi{Hotel, 12 Nächte} {2400.00}
%\STExpenses

% Rabatt
\Discount{Rabatt} {0} % 
            \end{invoice}
    \ps Bitte zahlen Sie den Gesamtbetrag unter Angabe der Rechnungsnummer auf das aufgeführte Konto.
    \ps Kleinunternehmerregelung:\\
    Im ausgewiesenen Betrag ist gemäß § 19 UStG keine Umsatzsteuer 
    enthalten.

    \closing{\invoiceClosing}
    \invoiceEnclosures
    \vspace*{3.9cm}
    \footnotesize \ps \textbf{Bankverbindung:}\hspace{6mm}\accountBankName, \accountIBAN, \accountBIC
    \footnotesize \ps \textbf{Steuernummer:}\hspace{8mm}\taxID



    \end{letter}
\end{document}

我想要一个 if 语句来检查是否\performaceEnd未定义或为空。如果为空，则\performanceDuration只会显示\performanceStart，如果\performanceEnd已定义，则显示\performanceStart{} -- \performanceEnd

我怎麼做呢？

答案1

编写测试的正确方法是

\ifx\performanceEnd\undefined
  \performanceStart
\else\ifx\performanceEnd\empty
  \performanceStart
\else
  \performanceStart{} -- \performanceEnd
\fi\fi

\ifperformanceEnd您还可以通过以下方式声明布尔值

\newif\ifperformanceEnd

在序言中的任何地方\performanceEnd检查

\performanceEndfalse
\ifx\performanceEnd\undefined\else
  \ifx\performanceEnd\empty\else
    \performanceEndtrue
\fi\fi

那么你可以写

\ifperformanceEnd
  \performanceStart{} -- \performanceEnd
\else
  \performanceStart
\fi

甚至

\performanceStart\ifperformanceEnd{} -- \performanceEnd\fi

答案2

好的，我们开始吧：正如@eric-domenjoud 指出的那样，您可以使用它\ifx来构建所需的文本变体。顺便说一句，考虑添加一个“seit”以明确表示表演时间尚未结束。

我在下面的代码中将错误写的变量更正\performaceStart为\performaceEnd正确的变量，\performanceStart并\performanceEnd在下面完整的代码中将其更正。

正如我们在您上一个问题中所做的那样，我们必须再次更改命令代码，\location如下所示：

\setkomavar{location}{%
      \\[\baselineskip] \\[\baselineskip]
      \flushright\small \invoicenr \invoiceReference\\[5pt]
      \customernr\\
      \customerNumber\\[5pt]
      \performanceDuration\\ 
\ifx\performanceEnd\undefined % <=======================================
  \performanceStart
\else\ifx\performanceEnd\empty
  \performanceStart
\else
  \performanceStart{} -- \performanceEnd
\fi\fi % <==============================================================
    }

然后我们得到以下代码（您需要使用问题链接的 zip 文件中的所有文件才能编译它！）

 \documentclass[a4paper]{scrlttr2}

\usepackage[top=2cm, bottom=1cm, left=2cm, right=2cm]{geometry}
\usepackage{graphicx}
\usepackage{lmodern}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[ngerman]{babel}
\usepackage{color}
\usepackage[hidelinks]{hyperref}
%\usepackage {ifthen}

\usepackage[german]{invoice}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\makeatletter
\def\UnitDay{Preis/Tag}% <========================================

\newcommand{\FeeDay@Title}{% <==========================================
    \\
    \noindent\textbf{\Activity}&&\UnitDay&\Count&\Amount\ (\BC)\\
    \hline%
}%

\newcommand{\FeeDay}[3]{% Yields state 3, Print Fee Item <==============
    %
    % #1 Contents
    % #2 Fee per Day
    % #3 Unit Count
    %
    \ifcase\Flag % 0: Invoice not started yet
        \error@message{\MissingOpening}%
        %
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \or % 1: Start invoice
        %
        \error@message{\MissingProject}%
        %
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \or % 2: Start project, print title
        %
        \FeeDay@Title%
        \Fee@Line{#1}{#2}{#3}%
        %
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \or % 3: Print remuneration item
        %
        \Fee@Line{#1}{#2}{#3}%
        %
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \or % 4: Print subtotal remuneration
        %
        \warning@message{\FeeSTExists}%
        %
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \or % 5: Expense item
        %
        \error@message{\FeeBeforeExpense}%
        %
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \or % 6: Print subtotal expenses
        %
        \error@message{\FeeBeforeExpense}%
        %
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \or % 7: Print subtotal project
        %
        \error@message{\ProjectCompletedNoFee}%
        %
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \or % 8: Print total, close invoice
        %
        \error@message{\InvoiceCompletedNoFee}%
        %
        %
    \else \error@message{\InternalError}%
    \fi%
}%
\makeatother


\renewcommand{\familydefault}{\sfdefault}

% include meta data
\include{_data} % <============== delete in this file the following data!
% ################## invoice DATA ##################
\newcommand{\invoiceDate}{\today} % Datum der rechnungsstellung
\newcommand{\invoiceReference}{2019\_01\_01\_1} % Rechnungsnummer (z.B. 20150122-4) YYYYMMDD-1
\newcommand{\invoiceSalutation}{Sehr geehrte Damen und Herren,} % die Anrede
\newcommand{\invoiceText}{Folgende Positionen werden in Rechnung gestellt:} % Rechnungstext
\newcommand{\invoiceEnclosures}{} % \encl{} einfügen
\newcommand{\invoiceClosing}{Mit freundlichen Grüßen}
% ################## invoice DATA ##################


% ##################Job DATA ####################
\def \performanceStart {01.01.2019}
%\def \performanceEnd {02.01.2019}
% ##################Job DATA ####################


% ################## Customer DATA ##################
\newcommand{\customerCompany}{Firma ABC} %ggf. Firma
\newcommand{\customerName}{Max Mustermann} % Name
\newcommand{\customerStreet}{Musterstraße 10} % Straße
\newcommand{\customerZIP}{12345} % Postleitzahl
\newcommand{\customerCity}{Musterort} % Ort
\newcommand{\customerNumber}{1000} % Kundennummer <==================
% ################## Customer DATA ##################

\setkomavar{fromname}{\senderName}
\setkomavar{fromaddress}{\senderStreet \\ \senderZIP \ \senderCity}
\setkomavar{place}{\senderCity}
\setkomavar{date}{\invoiceDate}
\setkomavar{fromphone}{\senderTelephone}
\setkomavar{frommobilephone}{\senderMobilephone}
\setkomavar{fromemail}{\href{mailto:\senderEmail}{\nolinkurl{\senderEmail}}}
\setkomavar{subject}{Rechnung}

\def \invoicenr{Rechnungsnummer: }% <========================================
\def \customernr{Kundennummer: }%
\def \performanceDuration{Leistungszeitraum: }

\setkomavar{location}{%
      \\[\baselineskip] \\[\baselineskip]
      \flushright\small \invoicenr \invoiceReference\\[5pt]
      \customernr\\
      \customerNumber\\[5pt]
      \performanceDuration\\ 
\ifx\performanceEnd\undefined % <=======================================
  \performanceStart
\else\ifx\performanceEnd\empty
  \performanceStart
\else
  \performanceStart{} -- \performanceEnd
\fi\fi % <==============================================================
    }


\setkomavar{firsthead}{\hfill
   \parbox[t][\headheight][t]{7.3cm}{% 
   \footnotesize
   \raggedright
   \flushright
   \color[gray]{.3}%
    \begin{tabular}{rl}
         Anschrift & \usekomavar{fromname}\\
         & \senderStreet\\
         & \senderZIP  \ \senderCity \\
         \\
         %\Telefon \ Telefon:  \` \senderTelephone \\
         Mobil  & \usekomavar{frommobilephone} \\
         E-Mail  & \usekomavar{fromemail} \\
        %Webseite & {\normalfont\ttfamily  \senderWeb } \\
         \\
         Steuernummer & \taxID \\
         \\
         Institut & \accountBankName \\
         IBAN & \accountIBAN \\
         BIC & \accountBIC
    \end{tabular}                   
   }%
}


\begin{document}
    \begin{letter}{\customerCompany \\ \customerName \\ 
    \customerStreet \\ \customerZIP \ \customerCity}


            \opening{\invoiceSalutation}
            \invoiceText
            \begin{invoice}{Euro}{0}

\ProjectTitle{Tagesleistungen} % 
\FeeDay{Freelance Arbeit}   {10}        {1}

\ProjectTitle{Projekttitel} % 
\Fee{Überstunden}           {20}    {1}



% Auslagen
%\EBC{Hotel, 12 Nächte} {2400.00} % \EBCi{Hotel, 12 Nächte} {2400.00}
%\STExpenses

% Rabatt
\Discount{Rabatt} {0} % 
            \end{invoice}
    \ps Bitte zahlen Sie den Gesamtbetrag unter Angabe der Rechnungsnummer auf das aufgeführte Konto.
    \ps Kleinunternehmerregelung:\\
    Im ausgewiesenen Betrag ist gemäß § 19 UStG keine Umsatzsteuer 
    enthalten.

        \closing{\invoiceClosing}
        \invoiceEnclosures



    \end{letter}
\end{document}

结果如下（请参阅我注释的定义\performanceEnd）：

生成的 pdf

如果你想添加“seit”，正如这个答案开头所说，你可以使用

\setkomavar{location}{%
      \\[\baselineskip] \\[\baselineskip]
      \flushright\small \invoicenr \invoiceReference\\[5pt]
      \customernr\\
      \customerNumber\\[5pt]
      \performanceDuration\\ 
\ifx\performanceEnd\undefined % <=======================================
  seit \performanceStart
\else\ifx\performanceEnd\empty
  seit \performanceStart
\else
  \performanceStart{} -- \performanceEnd
\fi\fi % <==============================================================
    }

结果如下：

在此处输入图片描述

相关内容