Question

如何将外部头文件中定义的struct包含到另一个文件中？起初，我通过指针传递结构，所以我只需要一个前向声明。但是现在我想通过价值来传递并且无法进行编译。标题lagerverwaltung.h确实包含结构，那么问题出在哪里？

档案lagerverwaltung.h：

#ifndef LAGERVERWALTUNG_H
#define LAGERVERWALTUNG_H

struct etikettInfo{
    QString userName;
    QList<struct properties_content *> inhalte;
};

class Lagerverwaltung : public QMainWindow
{
    Q_OBJECT
    ... and so on
};
#endif // LAGERVERWALTUNG_H

档案etikett1.h：

#ifndef ETIKETT1_H
#define ETIKETT1_H

#include "lagerverwaltung.h" // for struct etikettInfo
class Lagerverwaltung;
//struct etikettInfo;

namespace Ui {
class Etikett1;
}

class Etikett1 : public QMainWindow
{
    Q_OBJECT
public:
    explicit Etikett1(Lagerverwaltung *mainwindow,
                      etikettInfo etikettData,  // <- struct etikettInfo has not been declared
                      QWidget* parent = 0);
    ~Etikett1();

private:
    Ui::Etikett1 *ui;
    Lagerverwaltung *lgrvw;
    etikettInfo etikettData;   // <- struct etikettInfo does not name a type
};

#endif // ETIKETT1_H

如果重要：两个.h文件都有包括警卫。

好的错误消息（请参阅代码中的注释）非常具有描述性，但我不知道应该采取哪些不同的做法。

Answer 1

此外，我还在lagerverwaltung.h中加入了etikett1.h

你的错误。您在etikett1.h中加入了lagerverwaltung.h，其中包括etikett1.h，其中包含lagerverwaltung.h，依此类推。换句话说，您有一个循环依赖。您的包含防护可以防止无限包含，但也会导致其中一个标头包含在另一个标头之前。在这种情况下，lagerverwaltung.h首先包含在定义任何内容之前 - 特别是etikettInfo - 它包括etikett1.h ...这取决于尚未定义的etikettInfo。

如果lagerverwaltung.h真正取决于etikett1.h而且etikett1.h中lagerverwaltung.h所依赖的唯一内容是etikettInfo而lagerverwaltung.h中的任何内容都取决于etikettInfo etikettInfo然后最简单的解决方案是将etikett1.h的定义拆分为另一个标头，并将其包含在lagerverwaltung.h而不是require 'spec_helper' describe file('/home/ravendra/backup.sh') do its(:content) { should match /^ip=[$]1/ } its(:content) { should match /^ssh_port=[$]2/ } its(:content) { should match /^user=[$]3/ } its(:content) { should match /^TIMESTAMP=`date \S%y-%m-%d\w%H-%M-%S`/ } its(:content) { should match /^sh \/root\/backup_scripts\/openstack_backup.sh/ } its(:content) { should match /^sh \/root\/backup_scripts\/dashboard_backup.sh/ } its(:content) { should match /^tar -czvf musashi_backup-[$]TIMESTAMP.tar.gz \/musashi_backup/ } its(:content) { should match /^backup_remote_server  {/ } its(:content) { should match /^rsync -rvaz --progress -e "ssh -p [$]ssh_port" musashi_backup-[$]TIMESTAMP.tar.gz [$]user@(.*?).(.*?).(.*?):(~)\// } its(:content) { should match /^rsync -rvaz --progress -e "ssh -p [$]ssh_port" \/root\/backup_scripts\/restore.sh [$]user@(.*?).(.*?).(.*?):(~)\// } its(:content) { should match /^}/ } its(:content) { should match /^if \[ "[$]#" -eq 3 \]; then/ } its(:content) { should match /^backup_remote_server/ } its(:content) { should match /^fi/ } its(:content) { should match /^rsync -rvaz --progress musashi_backup-[$]TIMESTAMP.tar.gz \/musashi_backup\// } its(:content) { should match /^rsync -rvaz --progress \/root\/backup_scripts\/restore.sh \/musashi_backup\// } end describe file('/home/ravendra/backup_server.sh') do its(:content) { should match /^ip=[$]1/ } its(:content) { should match /^ssh_port=[$]2/ } its(:content) { should match /^user=[$]3/ } its(:content) { should match /^TIMESTAMP=`date \S%y-%m-%d\w%H-%M-%S`/ } its(:content) { should match /^is_IP  {/ } its(:content) { should match /^local stat=1/ } its(:content) { should match /^if \[\[ [$]ip =~ ^\[0-9\]{1,3}\\.\[0-9\]{1,3}\\.\[0-9\]{1,3}\\.\[0-9\]{1,3}[$] \]\]; then/ } its(:content) { should match /^OIFS=[$]IFS/ } its(:content) { should match /^IFS='.'/ } its(:content) { should match /^ip=$[$]ip$/ } its(:content) { should match /^IFS=[$]OIFS/ } its(:content) { should match /^\[\[ [$]{ip\[0\]} -le 255 && [$]{ip\[1\]} -le 255 \\/ } its(:content) { should match /^&& [$]{ip\[2\]} -le 255 && [$]{ip\[3\]} -le 255 \]\]/ } its(:content) { should match /^stat=[$]?/ } its(:content) { should match /^echo [$]stat/ } its(:content) { should match /^fi/ } its(:content) { should match /^return [$]stat/ } its(:content) { should match /^}/ } its(:content) { should match /^ip_ping  {/ } its(:content) { should match /^if \[\[ [$]$ping -q -c3 [$]ip$ == @$*100% packet loss*$ \]\]; then/ } its(:content) { should match /^echo "Unable to Ping the given Host"/ } its(:content) { should match /^echo "Note : Please check the value of 'kernel parameter net.ipv4.icmp_echo_ignore_all' at the location '\/proc\/sys\/net\/ipv4\/'.\\/ } its(:content) { should match /^If it's value is 1 then it will prevent other host from successfully pinging your server.In such case change it's \\/ } its(:content) { should match /^value to 0 for successful pinging. Please try again."/ } its(:content) { should match /^else/ } its(:content) { should match /^ssh_validation/ } its(:content) { should match /^fi/ } its(:content) { should match /^}/ } its(:content) { should match /^is_ssh_port  {/ } its(:content) { should match /^nc -z -w 3 [$]ip [$]ssh_port/ } its(:content) { should match /^if \[ "[$]?" -ne 0 \]; then/ } its(:content) { should match /^echo "Connection to" [$]ip "on port" [$]ssh_port "failed. Please try again."/ } its(:content) { should match /^else/ } its(:content) { should match /^echo "Connection to" [$]ip "on port" [$]ssh_port "succeeded"/ } its(:content) { should match /^backup_server/ } its(:content) { should match /^fi/ } its(:content) { should match /^}/ } its(:content) { should match /^backup_server  {/ } its(:content) { should match /^tar -czvf musashi_backup-[$]TIMESTAMP.tar.gz \/musashi_backup/ } its(:content) { should match /^rsync -rvaz --progress -e "ssh -p [$]ssh.port" musashi_backup-[$]TIMESTAMP.tar.gz [$]user@(.*?).(.*?).(.*?):(~)\// } its(:content) { should match /^rsync -rvaz --progress -e "ssh -p [$]ssh.port" \/root\/backup_scripts\/restore.sh [$]user@(.*?).(.*?).(.*?):(~)\// } its(:content) { should match /^create_cron/ } its(:content) { should match /^}/ } its(:content) { should match /^ip_validation  {/ } its(:content) { should match /^return_val=[$]$is_IP$/ } its(:content) { should match /^if \[ "[$]return_val" == 0 \]; then/ } its(:content) { should match /^ip_ping/ } its(:content) { should match /^elif \[ "[$]return_val" == 1 \]; then/ } its(:content) { should match /^echo "IP address should be in range of 0 to 255"/ } its(:content) { should match /^else/ } its(:content) { should match /^echo "Please put a valid IP addres"/ } its(:content) { should match /^fi/ } its(:content) { should match /^}/ } its(:content) { should match /^is_ssh  {/ } its(:content) { should match /^local stat=1/ } its(:content) { should match /^if \[\[ [$]ssh_port =~ ^$\[0-9\]{1,4}\|\[1-5\]\[0-9\]{4}\|6\[0-4\]\[0-9\]{3}\|65\[0-4\]\[0-9\]{2}\|655\[0-2\]\[0-9\]\|6553\[0-5\]$[$] \]\]; then/ } its(:content) { should match /^stat=[$]?/ } its(:content) { should match /^echo [$]stat/ } its(:content) { should match /^fi/ } its(:content) { should match /^return [$]stat/ } its(:content) { should match /^}/ } its(:content) { should match /^ssh_validation  {/ } its(:content) { should match /^return_val=[$]$is_ssh$/ } its(:content) { should match /^if \[ "[$]return_val" == 0 \]; then/ } its(:content) { should match /^is_ssh_port/ } its(:content) { should match /^else/ } its(:content) { should match /^echo "Please put a valid SSH port number. It should be in range of 0 to 65535."/ } its(:content) { should match /^fi/ } its(:content) { should match /^}/ } its(:content) { should match /^ create_cron  {/ } its(:content) { should match /^$ crontab -l \| grep -v \/root\/backup_scripts\/backup.sh $ \| crontab -/ } its(:content) { should match /^crontab -l \| { cat; echo "0 1 * * * \/root\/backup_scripts\/backup.sh [$]ip [$]ssh_port [$]user"; } \| crontab -/ } its(:content) { should match /^}/ } its(:content) { should match /^if \[ "[$]#" -eq 3 \]; then/ } its(:content) { should match /^ip_validation/ } its(:content) { should match /^else/ } its(:content) { should match /^echo "Please provide valid number of arguments."/ } its(:content) { should match /^fi/ } end中。

Answer 2

原来是

struct etikettInfo{
    QString userName;
    QList<struct properties_content *> inhalte;
};

需要正确的包含才能成为正确声明的结构。所以添加

#include <QString>
#include <QList>

以及properties_content的声明。

从头部包含struct

2 个答案: