Android中利用LocationManager来获取地理位置信息

川长思鸟来 2023-10-16 21:22 41阅读 0赞

**1.内容介绍：**

在Android应用开发中，可以使用系统框架层（Framework）提供的LocationManager来获取地理位置信息。

**2. 例子代码：**

第一步，需要在AndroidManifest.xml中添加相关权限。并且，在代码中需要根据版本来动态申请。

<uses-permission android:name="android.permission.ACCESSFINELOCATION"/>
    <uses-permission android:name="android.permission.ACCESSCOARSELOCATION"/>

第二步，真正的代码实现如下：

/**
         * 获取Location实例
         * @param context
         * @return
    */
    public Location getGpsLocation(Context context) {
            if (!isLocationPermissionGranted(context, LOCATION_TYPE_GPS)) {
                Trace.d(Trace.TagUtil, "user permission of location is not granted!");
                return null;
            }
    
            LocationManager locationManager = (LocationManager) context.
                    getSystemService(Context.LOCATION_SERVICE);
            Location location = null;
            try {
                location = Locations.getLastKnownLocation(locationManager,LocationManager.GPS_PROVIDER);
            } catch (Exception e) {
                Trace.d(e);
            }
            return location;
        }
    
    /**
         * 动态权限申请
         * @param context
         * @param locationType
         * @return
    */
    
    public boolean isLocationPermissionGranted(Context context, int locationType) {
            final int SDK = Build.VERSION.SDK_INT;
            final int Q = 29;
            boolean isQ = SDK == Q - 1 && getPreviewSDKInt() > 0 || Build.VERSION.SDK_INT >= Q;
            if (isQ) {
                int targetSdkVersion = context.getApplicationInfo().targetSdkVersion;
                if (targetSdkVersion > 28) {
                    if (CurrentStateUtil.isAppForground()) {
                        return checkLocationPermission(locationType);
                    } else {
                        return checkLocationPermission(locationType) && Utils.checkSelfPermission(context,
                                "android.permission.ACCESS_BACKGROUND_LOCATION") == PackageManager.PERMISSION_GRANTED;
                    }
                } else {
                    // System is Android Q
                    return checkLocationPermission(locationType);
                }
            } else {
                // System is NOT Android Q
                return checkLocationPermission(locationType);
            }
        }
    
    /**
         * 动态权限申请进一步封装
         * @param locationType
         * @return
    */
    private boolean checkLocationPermission(int locationType) {
            if (locationType == LOCATION_TYPE_GPS) {
                // GPS_PROVIDER need : ACCESS_FINE_LOCATION
                return Utils.getPermissionSafety(Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED;
            } else if (locationType == LOCATION_TYPE_NET) {
                // NETWORK_PROVIDER need : either ACCESS_FINE_LOCATION or ACCESS_COARSE_LOCATION
                return Utils.getPermissionSafety(Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED ||
                        Utils.getPermissionSafety(Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED;
            } else {
                return false;
            }
        }

动态获取权限工具类：

public static int getPermissionSafety(String permisson) {
            int ret = PackageManager.PERMISSION_DENIED;
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                try {
                    Context ctx = ExtensionContext.getInstance().context;
                    if (ctx != null)
                        ret = checkSelfPermission(ctx, permisson);
                } catch (Exception e) {
                    Trace.e("util", "getPermissSafety Exception " + e.toString());
                }
            } else {
                try {
                    Context ctx = ExtensionContext.getInstance().context;
                    if (ctx != null)
                        ret = ctx.getPackageManager().checkPermission(permisson, ctx.getPackageName());
    //                ret = ctx.checkCallingOrSelfPermission(permisson);
                } catch (Exception e) {
                    Trace.e("util", "getPermissSafety Exception " + e.toString());
                }
            }
            return ret;
        }

第三步，在Activity中调用：

private String getLocationInfo(Location location) { 
            String latLongStr; 
            TextView lo=(TextView)findViewById(R.id.textView1); 
            if(location!=null){ 
                double lat=location.getLatitude(); 
                double lng=location.getLongitude(); 
                latLongStr="lat:"+lat+";lng:"+lng; 
            }else { 
                latLongStr="";
            }
            return latLongStr;   
        }

说明：

getLocationInfo是自定义Activity中的一个方法，我们将Location作为参数，传入到getLocationInfo方法中，从而得到位置信息，作为字符串返回。

--------------------

不同的版本，不同的权限处理方式。