BlogJava-神奇好望角 The Magical Cape of Good Hope-文章分类-C/C++http://www.blogjava.net/shinzey/category/27552.htmlSic vis pacem para bellum.zh-cnFri, 07 Dec 2007 09:21:29 GMTFri, 07 Dec 2007 09:21:29 GMT60C 库函数 feof(FILE*) 判断文件末尾的问题http://www.blogjava.net/shinzey/articles/165906.html暴风雨骑士暴风雨骑士Thu, 06 Dec 2007 15:05:00 GMThttp://www.blogjava.net/shinzey/articles/165906.htmlhttp://www.blogjava.net/shinzey/comments/165906.htmlhttp://www.blogjava.net/shinzey/articles/165906.html#Feedback0http://www.blogjava.net/shinzey/comments/commentRss/165906.htmlhttp://www.blogjava.net/shinzey/services/trackbacks/165906.html C 库函数 feof(FILE*) 判断文件末尾的问题 A Problem on Using C Library Function feof(FILE*) to Judge The End of A File 　　嘟嘟用 C 写了一个程序读取 32768 字节大小的文件，每次读 16 个字节，应该是 2048 次读完。但结果读了 2049 次，并且最后两次的数据相同，似乎重复读取了最后 16 个字节。源代码如下：     Dudu wrote a program with C, which read a file of 32768 bytes, 16 bytes each time, and it should finish reading after 2048 times. But the reault was it read 2049 times, and the data of last two times are the same, which seemed the last 16 bytes were read twice. Here is the code:
  1. int loop = 0;
  2. while (!feof(file)) {
  3.     loop++;
  4.     fread(buffer, 16, 1, file);
  5.     ......
  6. }
  7. printf("%d\n", loop);    // 2049
　　我看了一阵，发现导致这个错误的原因是 feof(FILE*) 判断文件末尾的机制：文件指针在文件末尾的时候，除非再读一次导致发生 I/O 错误，feof(FILE*) 依然返回 0。因此用 feof(FILE*) 作为判断条件的 while 循环始终会多读一次，而最后一次的读取是失败的，buffer 也就没有改变，看起来就像是重复读了一次。     I reviewed it for a whil and found the reason that produced this error is the mechanism feof(FILE*) used to judge the end of a file: When the file pointer is at the end of a file, feof(FILE*) still returns 0 unless reads one more time to course a I/O error. Therefore, a while loop using feof(FILE*) as the judgment condition always reads one more time, and the last time of reading will fail, so buffer stayed unchanged which looked like it repeated reading once. 　　用下面的代码就没问题了：     Use the code below to solve this problem:
  1. int loop = 0;
  2. while (fread(buffer, 16, 1, file) == 1) {
  3.     loop++;
  4.     ......
  5. }
  6. printf("%d\n", loop); // 2048


暴风雨骑士 2007-12-06 23:05 发表评论
]]>用 NetBeans 开发一个简单的 Windows XP 程序 - 其三http://www.blogjava.net/shinzey/articles/163331.html暴风雨骑士暴风雨骑士Mon, 26 Nov 2007 13:25:00 GMThttp://www.blogjava.net/shinzey/articles/163331.htmlhttp://www.blogjava.net/shinzey/comments/163331.htmlhttp://www.blogjava.net/shinzey/articles/163331.html#Feedback0http://www.blogjava.net/shinzey/comments/commentRss/163331.htmlhttp://www.blogjava.net/shinzey/services/trackbacks/163331.html 用 NetBeans 开发一个简单的 Windows XP 程序 - 其三 Developing A simple Windows XP Application with NetBeans - Part 3 　　新建一个名为 MyMakefile.mk 的 Makefile，内容如下：     Create a new Makefile named MyMakefile.mk of the following content:
  1. PRJ=dist/Release/WinHello.exe
  2. OBJ=build/Release/WinHello.o build/Release/Resource.o
  3. CC=gcc
  4. CFLAGS=-mwindows -s
  5. RES=windres
  6. LIB=-lcomctl32
  8. $(PRJ): $(OBJ)
  9.     mkdir -p dist/Release
  10.     $(CC) $(CFLAGS) -o dist/Release/WinHello $(OBJ) $(LIB)
  12. build/Release/WinHello.o: WinHello.c
  13.     mkdir -p build/Release
  14.     $(CC) $(CFLAGS) -c -O4 -o build/Release/WinHello.o WinHello.c
  16. build/Release/Resource.o: Resource.rc
  17.     mkdir -p build/Release
  18.     $(RES) -o build/Release/Resource.o Resource.rc
  20. .PHONY: clean
  21. clean:
  22.     ${RM} $(OBJ) $(PRJ)
　　注意由于排版问题，制表符被扩展成了空格。把这个 Makefile 添加进项目，在上面右键选择“make”，就能得到如下的预期效果了：     Note that because of typesetting, tabs are expanded to spaces. Add this Makefile to the project, right click and select "make", and the following result is shown as expected:

暴风雨骑士 2007-11-26 21:25 发表评论
]]>用 NetBeans 开发一个简单的 Windows XP 程序 - 其二http://www.blogjava.net/shinzey/articles/163328.html暴风雨骑士暴风雨骑士Mon, 26 Nov 2007 13:14:00 GMThttp://www.blogjava.net/shinzey/articles/163328.htmlhttp://www.blogjava.net/shinzey/comments/163328.htmlhttp://www.blogjava.net/shinzey/articles/163328.html#Feedback0http://www.blogjava.net/shinzey/comments/commentRss/163328.htmlhttp://www.blogjava.net/shinzey/services/trackbacks/163328.html 用 NetBeans 开发一个简单的 Windows XP 程序 - 其二 Developing A simple Windows XP Application with NetBeans - Part 2 　　在项目节点上右键转到“属性 → C/C++ → C 编译器”节点，在“命令行”中设置“其他选项”为 -mwindows；再转到“链接器 → 库”，单击“库”右边的省略号按钮，接着单击“添加选项”，设置“其他选项”为 -lcomctl32。     Right click the project node and go to "Properties → C/C++ → C Compiler" node, in "Command Line" set "Additonal Options" to -mwindows; then go to "Linker → Libraries", click the ellipsis button to the right of "Libraries", click "Add Option" and set "Other Option" to -lcomctl32. 　　这时如果直接执行“生成项目”，则会输出以下错误：     If we directly execute "Build Project" right now, the following errors will be complained:
  1. WinHello.c:6: error: `INITCOMMONCONTROLSEX' undeclared (first use in this function)
  2. WinHello.c:6: error: (Each undeclared identifier is reported only once
  3. WinHello.c:6: error: for each function it appears in.)
  4. WinHello.c:6: error: parse error before "init"
  5. WinHello.c:7: error: `init' undeclared (first use in this function)
  6. WinHello.c:8: error: `ICC_STANDARD_CLASSES' undeclared (first use in this function)
　　结构体 INITCOMMONCONTROLSEX 在 commctrl.h 中声明，commctrl.h 位于 mingw\include。打开这个头文件，查找 INITCOMMONCONTROLSEX，发现它包含在一段预处理指令中：     Constuct INITCOMMONCONTROLSEX is decleared in commctrl.h, which is inside mingw\include. Open this header file and search INITCOMMONCONTROLSEX, and the following segment of preprocessed commands will be found:
  1. #if (_WIN32_IE >= 0x0300)
  2. typedef struct tagINITCOMMONCONTROLSEX {
  3.     DWORD dwSize;
  4.     DWORD dwICC;
  5. } INITCOMMONCONTROLSEX,*LPINITCOMMONCONTROLSEX;
  6. #endif
　　再查找 _WIN32_IE，找到：     Then search _WIN32_IE and find:
  1. #if 0
  2. #define _WIN32_IE 0x0300
  3. #endif
　　#if 0 表示在默认情况下，永远不会定义 _WIN32_IE。注释掉行 1 和行 3，再编译，仍然出错：     #if 0 means _WIN32_IE would never be definded by default. Comment line 1 and line 3, compile and still gets errors:
  1. WinHello.c:8: error: `ICC_STANDARD_CLASSES' undeclared (first use in this function)
  2. WinHello.c:8: error: (Each undeclared identifier is reported only once
  3. WinHello.c:8: error: for each function it appears in.)
　　像上面一样去查找 ICC_STANDARD_CLASSES，这次要把 windef.h 中的 WINVER 改为 0x0501。我觉得不必担心改了这些会带来什么坏处。这些变量存在的意义是定义或不定义一些 API，以便为不同版本的 Windows 开发程序。如今 Windows Vista 已经出来了，世界进步很快，有新东西为什么不用呢？     Search ICC_STANDARD_CLASSES as above, and this time modify WINVER in windef.h to 0x0501. I don't think it necessary to warry that these modifications do any thing bad. The purpose of the existance of these variables is to define some APLs or not, for the sake of developing applications for various versions of Windows. Windows Vista has been present, and the world is rapidly progressing, so why not use new things? 　　现在编译运行，不会出错了，但风格是 9x/2000 那种老土的，这是因为默认情况下 NetBeans 不知道如何编译 rc 文件。解决这一问题的办法是自定义一个 Makefile。     Compile, run, and no error now, but the style is ugly as 9x/2000's, that's because by default NetBeans dosen't know how to compile rc files. The solution to this peoblem is to write a custom Makefile. 　　好像差不多长了，下次继续。     This seems long enough and is to be continued next time.

暴风雨骑士 2007-11-26 21:14 发表评论
]]>用 NetBeans 开发一个简单的 Windows XP 程序 - 其一http://www.blogjava.net/shinzey/articles/163013.html暴风雨骑士暴风雨骑士Sun, 25 Nov 2007 12:47:00 GMThttp://www.blogjava.net/shinzey/articles/163013.htmlhttp://www.blogjava.net/shinzey/comments/163013.htmlhttp://www.blogjava.net/shinzey/articles/163013.html#Feedback0http://www.blogjava.net/shinzey/comments/commentRss/163013.htmlhttp://www.blogjava.net/shinzey/services/trackbacks/163013.html 用 NetBeans 开发一个简单的 Windows XP 程序 - 其一 Developing A simple Windows XP Application with NetBeans - Part 1 　　首先创建一个名为 WinHello 的项目，在“源代码”节点下新建 WinHello.c，代码的内容如下：     First create a project with the name WinHello, and then create a new WinHello.c under "Source Files" node with the following code:
  1. #include <windows.h>
  2. #include <commctrl.h>
  4. int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
  5.             PSTR szCmdLine, int iCmdShow) {
  6.     INITCOMMONCONTROLSEX init;
  7.     init.dwSize = sizeof(init);
  8.     init.dwICC = ICC_STANDARD_CLASSES;
  9.     InitCommonControlsEx(&init);
  10.     MessageBox(NULL, TEXT("再来！"), TEXT("哈哈~"), 0);
  11.     return 0;
  12. }
　　注意末尾处最好再加上一个回车符，因为我们将用 MinGW GCC 来编译，遵循 UNIX 的规矩总是好的。行 6~9 指明用 Windows XP 风格初始化程序，但这还不够，我们还需要一个资源脚本和一个清单文件来显示调用 Comctl32.dll 版本 6（默认状态下自动调用版本 5，也就是 Windows 9x/2000 风格）。在“资源文件”节点下新建资源脚本 resource.rc 和清单文件 WinHello.exe.manifest。resource.rc 的内容如下：     Attention it's best to add a CR in the end, because we'll compile it with MinGW GCC, so it's always good to follow the UNIX conventions. Line 6~9 indicates Windows XP style will be used to initialize the application, but that's not enough. We still need a resource script and a manifest file to explicitly invoke Comctl32.dll version 6 (version 5 is automatically invoked by default which is Windows 9x/2000 style). Create a new resource script resource.rc and a manifest file WinHello.exe.manifest. The content of resource.rc is as below:
  1. #include <windows.h>
  3. CREATEPROCESS_MANIFEST_RESOURCE_ID RT_MANIFEST "Winhello.exe.manifest"
　　WinHello.exe.manifest 的内容如下：     The content of WinHello.exe.manifest is as below:
  1. <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
  2. <assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
  3. <assemblyIdentity
  4.     version="1.0.0.0"
  5.     processorArchitecture="X86"
  6.     name="zhyi.zhyi.Winhello"
  7.     type="win32"
  8. />
  9. <description>Description.</description>
  10. <dependency>
  11.     <dependentAssembly>
  12.         <assemblyIdentity
  13.             type="win32"
  14.             name="Microsoft.Windows.Common-Controls"
  15.             version="6.0.0.0"
  16.             processorArchitecture="X86"
  17.             publicKeyToken="6595b64144ccf1df"
  18.             language="*"
  19.         />
  20.     </dependentAssembly>
  21. </dependency>
  22. </assembly>

　　到现在为止，所有的源文件都准备好了，接下来是编译。为避免一篇文章过长，且看下回分解。     By now all source files are ready, and next job is compiling. For avoiding a too long article, please read the next part.

暴风雨骑士 2007-11-25 20:47 发表评论
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