首先說一下qt編程的步驟，然后再仔細說一下qmake的使用。我看書上的都是編寫好cpp文件后，分別執行命令: qmake -project、qmake、make，然后執行就可以了，但是要是我在一個文件夾下有多個cpp文件，qmake怎么識別？make生成的最后執行文件的名，我怎么能隨心所欲的自己定？帶著疑問，找了網上的資料，不如所衣，然后嘗試著gcc編譯的思想竟然撞到了。

其實我感覺要要真正了解qmake的使用方法，直接在終端下輸入命令：qmake -help就可以了，我也是這樣做的，幫助內容如下

    Usage: qmake [mode] [options] [files]

QMake has two modes, one mode for generating project files based on
some heuristics, and the other for generating makefiles. Normally you
shouldn't need to specify a mode, as makefile generation is the default
mode for qmake, but you may use this to test qmake on an existing project

Mode:
  -project       Put qmake into project file generation mode
                 In this mode qmake interprets files as files to
                 be built,
                 defaults to *.c; *.ui; *.y; *.l; *.ts; *.xlf; *.qrc; *.h; *.hpp; *.hh; *.hxx; *.H; *.cpp; *.cc; *.cxx; *.C
                 Note: The created .pro file probably will 
                 need to be edited. For example add the QT variable to 
                 specify what modules are required.
  -makefile      Put qmake into makefile generation mode (default)
                 In this mode qmake interprets files as project files to
                 be processed, if skipped qmake will try to find a project
                 file in your current working directory

Warnings Options:
  -Wnone         Turn off all warnings; specific ones may be re-enabled by
                 later -W options
  -Wall          Turn on all warnings
  -Wparser       Turn on parser warnings
  -Wlogic        Turn on logic warnings (on by default)
  -Wdeprecated   Turn on deprecation warnings (on by default)

Options:
   * You can place any variable assignment in options and it will be     *
   * processed as if it was in [files]. These assignments will be parsed *
   * before [files].                                                     *
  -o file        Write output to file
  -d             Increase debug level
  -t templ       Overrides TEMPLATE as templ
  -tp prefix     Overrides TEMPLATE so that prefix is prefixed into the value
  -help          This help
  -v             Version information
  -after         All variable assignments after this will be
                 parsed after [files]
  -norecursive   Don't do a recursive search
  -recursive     Do a recursive search
  -set <prop> <value> Set persistent property
  -unset <prop>  Unset persistent property
  -query <prop>  Query persistent property. Show all if <prop> is empty.
  -cache file    Use file as cache           [makefile mode only]
  -spec spec     Use spec as QMAKESPEC       [makefile mode only]
  -nocache       Don't use a cache file      [makefile mode only]
  -nodepend      Don't generate dependencies [makefile mode only]
  -nomoc         Don't generate moc targets  [makefile mode only]
  -nopwd         Don't look for files in pwd [project mode only]
song@ubuntu:~/lianxi/qt$ clear

song@ubuntu:~/lianxi/qt$ qmake -help
Usage: qmake [mode] [options] [files]

QMake has two modes, one mode for generating project files based on
some heuristics, and the other for generating makefiles. Normally you
shouldn't need to specify a mode, as makefile generation is the default
mode for qmake, but you may use this to test qmake on an existing project

Mode:
  -project       Put qmake into project file generation mode
                 In this mode qmake interprets files as files to
                 be built,
                 defaults to *.c; *.ui; *.y; *.l; *.ts; *.xlf; *.qrc; *.h; *.hpp; *.hh; *.hxx; *.H; *.cpp; *.cc; *.cxx; *.C
                 Note: The created .pro file probably will 
                 need to be edited. For example add the QT variable to 
                 specify what modules are required.
  -makefile      Put qmake into makefile generation mode (default)
                 In this mode qmake interprets files as project files to
                 be processed, if skipped qmake will try to find a project
                 file in your current working directory

Warnings Options:
  -Wnone         Turn off all warnings; specific ones may be re-enabled by
                 later -W options
  -Wall          Turn on all warnings
  -Wparser       Turn on parser warnings
  -Wlogic        Turn on logic warnings (on by default)
  -Wdeprecated   Turn on deprecation warnings (on by default)

Options:
   * You can place any variable assignment in options and it will be     *
   * processed as if it was in [files]. These assignments will be parsed *
   * before [files].                                                     *
  -o file        Write output to file
  -d             Increase debug level
  -t templ       Overrides TEMPLATE as templ
  -tp prefix     Overrides TEMPLATE so that prefix is prefixed into the value
  -help          This help
  -v             Version information
  -after         All variable assignments after this will be
                 parsed after [files]
  -norecursive   Don't do a recursive search
  -recursive     Do a recursive search
  -set <prop> <value> Set persistent property
  -unset <prop>  Unset persistent property
  -query <prop>  Query persistent property. Show all if <prop> is empty.
  -cache file    Use file as cache           [makefile mode only]
  -spec spec     Use spec as QMAKESPEC       [makefile mode only]
  -nocache       Don't use a cache file      [makefile mode only]
  -nodepend      Don't generate dependencies [makefile mode only]
  -nomoc         Don't generate moc targets  [makefile mode only]
  -nopwd         Don't look for files in pwd [project mode only]

  

qmake命令格式

qmake [mode] [options] [files]

mode選項

-project 生成.pro文件

-makefile 生成Makefile文件

options選項(這里介紹幾個常用的，其它的自己去翻譯上面,其實我也是剛學，用到的時候再學習哈)

-o file 輸出文件名，比如qmake -project hello.cpp -o hello.pro，就會生成一個hello.pro文件，如果是qmake -project hello.cpp -o hello11.pro，就會生成一個hello11.pro文件

實驗1

1、編寫代碼，命名為hello.cpp，如下

hello.cpp代碼如下

    #include<qapplication.h>
#include<qpushbutton.h>

int main(int argc,char *argv[])
{
    QApplication a(argc,argv);
    QPushButton hellobtn("Hello World!",0);
    hellobtn.resize(200,50);
    hellobtn.show();
    return a.exec();
}

  

2、 qmake -project (用于創建.pro文件，將所有的文件編譯成一個與平臺無關的工程文件)

可見默認生成的文件名為 qt.pro

3、 qmake (讀取本身的Qt設置，生成與庫一致的相應的Makefile)

4、 make (根據生成的Makefile，將文件編譯為二進制可執行程序)

可見生成了qt可執行程序

5、執行命令： ./qt

實驗2

本實驗中并沒有用到上面所講的方式，而是直接使用了默認值，但是假設說該文件夾下有兩個cpp文件，如下圖

這時候再執行命令：qmake -project會怎么樣呢？會出現下面的結果

有點意思，竟然不出錯，但是你知道它生成的qt.pro是哪個cpp文件的嗎？我不知道，加入這里我想對test.cpp操作，這時候就要按照上面的格式了。

1、qmake -project test.cpp -o test.pro

這時候生成了test.pro

2、qmake -makefile test.pro，這里生成test.pro的Makefile

3、make

4、執行命令 ./test

Qt編程中qmake的使用詳解