# 新建应用程序<a name="ZH-CN_TOPIC_0000001171455556"></a>

下方将通过修改源码的方式展示如何编写简单程序，输出“Hello OHOS！”。请在[获取源码](quickstart-lite-sourcecode-acquire.md)章节下载的源码目录中进行下述操作。

1.  新建目录及源码。

    新建**applications/sample/camera/apps/src/helloworld.c**目录及文件，代码如下所示，用户可以自定义修改打印内容（例如：修改OHOS为World）。当前应用程序可支持标准C及C++的代码开发。

    ```
    #include <stdio.h>
    
    int main(int argc, char **argv)
    {
        printf("\n************************************************\n");
        printf("\n\t\tHello OHOS!\n");
        printf("\n************************************************\n\n");
    
        return 0;
    }
    ```

2.  新建编译组织文件。

    新建**applications/sample/camera/apps/BUILD.gn**文件，内容如下所示：

    ```
    import("//build/lite/config/component/lite_component.gni")
    lite_component("hello-OHOS") {
      features = [ ":helloworld" ]
    }
    executable("helloworld") {
      output_name = "helloworld"
      sources = [ "src/helloworld.c" ]
      include_dirs = []
      defines = []
      cflags_c = []
      ldflags = []
    }
    ```

3.  添加新组件。

    修改文件**build/lite/components/applications.json**，添加组件hello\_world\_app的配置，如下所示为applications.json文件片段，"\#\#start\#\#"和"\#\#end\#\#"之间为新增配置（"\#\#start\#\#"和"\#\#end\#\#"仅用来标识位置，添加完配置后删除这两行）：

    ```
    {
      "components": [
        {
          "component": "camera_sample_communication",
          "description": "Communication related samples.",
          "optional": "true",
          "dirs": [
            "applications/sample/camera/communication"
          ],
          "targets": [
            "//applications/sample/camera/communication:sample"
          ],
          "rom": "",
          "ram": "",
          "output": [],
          "adapted_kernel": [ "liteos_a" ],
          "features": [],
          "deps": {
            "components": [],
            "third_party": []
          }
        },
    ##start##
        {
          "component": "hello_world_app",
          "description": "Communication related samples.",
          "optional": "true",
          "dirs": [
            "applications/sample/camera/apps"
          ],
          "targets": [
            "//applications/sample/camera/apps:hello-OHOS"
          ],
          "rom": "",
          "ram": "",
          "output": [],
          "adapted_kernel": [ "liteos_a" ],
          "features": [],
          "deps": {
            "components": [],
            "third_party": []
          }
        },
    ##end##
        {
          "component": "camera_sample_app",
          "description": "Camera related samples.",
          "optional": "true",
          "dirs": [
            "applications/sample/camera/launcher",
            "applications/sample/camera/cameraApp",
            "applications/sample/camera/setting",
            "applications/sample/camera/gallery",
            "applications/sample/camera/media"
          ],
    ```

4.  修改单板配置文件。

    修改文件**vendor/hisilicon/hispark\_taurus/config.json**，新增hello\_world\_app组件的条目，如下所示代码片段为applications子系统配置，"\#\#start\#\#"和"\#\#end\#\#"之间为新增条目（"\#\#start\#\#"和"\#\#end\#\#"仅用来标识位置，添加完配置后删除这两行）：

    ```
          {
            "subsystem": "applications",
            "components": [
              { "component": "camera_sample_app", "features":[] },
              { "component": "camera_sample_ai", "features":[] },
    ##start##
              { "component": "hello_world_app", "features":[] },
    ##end##
              { "component": "camera_screensaver_app", "features":[] }
            ]
          },
    ```