
想了解更多内容,取位请访问:
和华为官方合作共建的置信鸿蒙技术社区
https://harmonyos.51cto.com
前言
随着科技时代的发展,生活中每个人都离不开手机,取位当我们去一个陌生的置信地方,不认识路怎么办,取位大家都会想到手机里的置信百度地图、高德地图等等。取位生活中我们不想做饭也不想出门的置信时候,我们会想到美团,取位那么美团APP怎么知道你的置信位置信息呢?当你进入app时,页面中就会提示你是取位否允许获取位置信息,服务器租用当你点击允许时,置信就会把位置信息展示在页面中。取位今天我们就来讲解一下HarmonyOS 如何使用Java UI框架获取手机位置权限并拿到位置信息。置信
使用DevEco Studio 创建空项目,取位选择java模板
File => New Project


编写基础布局
<?xml version="1.0" encoding="utf-8"?> <DirectionalLayout     xmlns:ohos="http://schemas.huawei.com/res/ohos"     ohos:height="match_parent"     ohos:width="match_parent"     ohos:alignment="top|center"     ohos:orientation="vertical">      <Text         ohos:id="$+id:T_Longitude"         ohos:height="match_content"         ohos:width="match_parent"         ohos:background_element="green"         ohos:margin="10vp"         ohos:padding="10vp"         ohos:text="--"         ohos:text_alignment="left|vertical_center"         ohos:text_size="28fp"/>     <Text         ohos:id="$+id:T_Latitude"         ohos:height="match_content"         ohos:width="match_parent"         ohos:margin="10vp"         ohos:padding="10vp"         ohos:background_element="green"         ohos:text="--"         ohos:text_alignment="left|vertical_center"         ohos:text_size="28fp"/>     <Text         ohos:id="$+id:T_country"         ohos:height="match_content"         ohos:width="match_parent"         ohos:margin="10vp"         ohos:padding="10vp"         ohos:background_element="green"         ohos:text="--"         ohos:text_alignment="left|vertical_center"         ohos:text_size="28fp"/>     <Text         ohos:id="$+id:T_PlaceName"         ohos:height="match_content"         ohos:width="match_parent"         ohos:margin="10vp"         ohos:multiple_lines="true"         ohos:padding="10vp"         ohos:background_element="green"         ohos:text="--"         ohos:text_alignment="left|vertical_center"         ohos:text_size="28fp"/>     <Button         ohos:id="$+id:btn_location"         ohos:height="match_content"         ohos:width="match_content"         ohos:text="点击获取定位"         ohos:padding="10vp"         ohos:background_element="green"         ohos:text_alignment="vertical_center"         ohos:text_size="28fp"/> </DirectionalLayout>         日志工具类 LogUtil
写好布局后,我们先准备一个日志工具类,用于打印日志。
/**  *日志工具类  */ public class LogUtil {    static HiLogLabel hiLogLabel = new HiLogLabel(HiLog.LOG_APP,233,"LOCATION_TAG");     public static void info(String content){         HiLog.info(hiLogLabel,content);      } public static void error(String content){         HiLog.info(hiLogLabel,content);      } public static void debug(String content){         HiLog.info(hiLogLabel,content);     } }         配置位置权限 config.js
位置信息属于敏感信息,使用之前我们需要申请权限
"reqPermissions": [      {        "name": "ohos.permission.LOCATION",        "reason": "",        "usedScene": {          "ability": ["com.example.location.MainAbility"],          "when": "inuse"        }      }    ]         MainAbility 中获取位置信息
public class MainAbility extends Ability {     Locator locator;     MyLocatorCallback locatorCallback;     RequestParam requestParam;     final int REQUEST_LOCATION_CODE = 12; // 定义常量 用来表示请求码     // 创建一个静态成员变量 数据共享     public static Location location = null;      @Override     public void onStart(Intent intent) {         super.onStart(intent);         super.setMainRoute(MainAbilitySlice.class.getName());         // 动态判断权限         if (verifySelfPermission("ohos.permission.LOCATION") != IBundleManager.PERMISSION_GRANTED) {             // 应用未被授予权限             if (canRequestPermission("ohos.permission.LOCATION")) {                 // 是否可以申请弹框授权(首次申请或者用户未选择禁止且不再提示)                 requestPermissionsFromUser(new String[]{"ohos.permission.LOCATION"}, REQUEST_LOCATION_CODE);                 LogUtil.info("canRequestPermission() running");             } else {                 // 显示应用需要权限的理由,提示用户进入设置授权                 LogUtil.info("显示应用需要权限的理由");             }         } else {             initLocator();             // 权限已被授予             LogUtil.info("权限已被授予,直接启动服务");         }      }      @Override // 权限操作调用的方法     public void onRequestPermissionsFromUserResult(int requestCode, String[] permissions, int[] grantResults) {         super.onRequestPermissionsFromUserResult(requestCode, permissions, grantResults);         switch (requestCode) {             case REQUEST_LOCATION_CODE: {                 // 匹配requestPermissions的requestCode                 if (grantResults.length > 0                         && grantResults[0] == IBundleManager.PERMISSION_GRANTED) {                     LogUtil.info("onRequestPermissionsFromUserResult权限被授予");                     // 权限被授予                     // 注意:因时间差导致接口权限检查时有无权限,所以对那些因无权限而抛异常的免费源码下载接口进行异常捕获处理                     initLocator();                 } else {                     // 权限被拒绝                     LogUtil.info("onRequestPermissionsFromUserResult权限被拒绝");                 }                 return;             }         }     }      private void initLocator() {         locator = new Locator(this); // 创建local对象         // 实例化RequestParam对象,用于告知系统该向应用提供何种类型的位置服务,以及位置结果上报的频率。         requestParam = new RequestParam(RequestParam.SCENE_NAVIGATION);         // 实现 locatorCallback 接口对象         locatorCallback = new MyLocatorCallback();         // locator.requestOnce(requestParam, locatorCallback); // 请求一次         locator.startLocating(requestParam, locatorCallback); // 多次请求 直接启动服务     }      @Override     protected void onStop() {         super.onStop();         locator.stopLocating(locatorCallback); // 程序结束 停止服务     }      // 创建MyLocatorCallback类,实现LocatorCallback接口,用于执行定位过程的回调方法     public class MyLocatorCallback implements LocatorCallback {         @Override // 获取定位结果         public void onLocationReport(Location location) { // 使用静态成员变量 进行分享             LogUtil.info("onLocationReport:" + location.getLongitude() + "," + location.getLatitude());             if (location != null) {                 MainAbility.location = location;             }         }          @Override // 获取定位过程中的状态信息         public void onStatusChanged(int type) {             LogUtil.info("onStatusChanged:" + type);          }          @Override // 获取定位过程中的错误信息         public void onErrorReport(int type) {             LogUtil.info("onErrorReport:" + type);         }     } }         更新视图
通过以上操作,我们拿到了位置信息,接下来我们需要把位置信息渲染到视图中
public class MainAbilitySlice extends AbilitySlice {     Text t_Longitude;     Text t_Latitude;     Text t_country;     Text t_PlaceName;      @Override     public void onStart(Intent intent) {         super.onStart(intent);         super.setUIContent(ResourceTable.Layout_ability_main);         // 获取UI布局中的id,用于数据绑定         t_Longitude = (Text) findComponentById(ResourceTable.Id_T_Longitude);         t_Latitude = (Text) findComponentById(ResourceTable.Id_T_Latitude);         t_PlaceName = (Text) findComponentById(ResourceTable.Id_T_PlaceName);         t_country = (Text) findComponentById(ResourceTable.Id_T_country);          findComponentById(ResourceTable.Id_btn_location).setClickedListener(new Component.ClickedListener() {             @Override             public void onClick(Component component) {                 loadLocation();             }         });     }      private void loadLocation(){         // 在UI线程中更新组件         getUITaskDispatcher().asyncDispatch(new Runnable() {             @Override             public void run() {                 // 是UI中的操作                 if(location == null)return;                 t_Longitude.setText("经度:"+location.getLongitude() +"");                 t_Latitude.setText("纬度:"+location.getLatitude() +"");                 // (逆)地理编码转换                 GeoConvert geoConvert = new GeoConvert();                 try {                     List<GeoAddress> list = geoConvert.getAddressFromLocation(location.getLatitude(),location.getLongitude(),1);                     GeoAddress geoAddress = list.get(0);                     if(geoAddress == null) return;                     t_PlaceName.setText("位置:"+geoAddress.getPlaceName()+"");                     t_country.setText("国家:"+geoAddress.getCountryName()+"");                 } catch (IOException e) {                     e.printStackTrace();                 }             }         });     }      @Override     public void onActive() {         super.onActive();     }      @Override     public void onForeground(Intent intent) {         super.onForeground(intent);     } }         实现效果图如下:

想了解更多内容,请访问:
和华为官方合作共建的网站模板鸿蒙技术社区
https://harmonyos.51cto.com

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