通过ExifInterface可以将拍照时的一些属性信息写入图片文件里，其中包括经纬度信息。本文介绍一种将经纬度坐标写入JPEG图片文件的方法！
核心代码
/** * 浮点型经纬度值转成度分秒格式 * * @param coord * @return */ public String decimalToDMS(double coord) { String output, degrees, minutes, seconds; // gets the modulus the coordinate divided by one (MOD1). // in other words gets all the numbers after the decimal point. // e.g. mod := -79.982195 % 1 == 0.982195 // // next get the integer part of the coord. On other words the whole // number part. // e.g. intPart := -79 double mod = coord % 1; int intPart = (int) coord; // set degrees to the value of intPart // e.g. degrees := "-79" degrees = String.valueOf(intPart); // next times the MOD1 of degrees by 60 so we can find the integer part // for minutes. // get the MOD1 of the new coord to find the numbers after the decimal // point. // e.g. coord := 0.982195 * 60 == 58.9317 // mod := 58.9317 % 1 == 0.9317 // // next get the value of the integer part of the coord. // e.g. intPart := 58 coord = mod * 60; mod = coord % 1; intPart = (int) coord; if (intPart < 0) { // Convert number to positive if it's negative. intPart *= -1; } // set minutes to the value of intPart. // e.g. minutes = "58" minutes = String.valueOf(intPart); // do the same again for minutes // e.g. coord := 0.9317 * 60 == 55.902 // e.g. intPart := 55 coord = mod * 60; intPart = (int) coord; if (intPart < 0) { // Convert number to positive if it's negative. intPart *= -1; } // set seconds to the value of intPart. // e.g. seconds = "55" seconds = String.valueOf(intPart); // I used this format for android but you can change it // to return in whatever format you like // e.g. output = "-79/1,58/1,56/1" output = degrees + "/1," + minutes + "/1," + seconds + "/1"; // Standard output of D°M′S″ // output = degrees + "°" + minutes + "'" + seconds + "\""; return output; } /** * 将经纬度信息写入JPEG图片文件里 * * @param picPath * JPEG图片文件路径 * @param dLat * 纬度 * @param dLon * 经度 */ public void writeLatLonIntoJpeg(String picPath, double dLat, double dLon) { File file = new File(picPath); if (file.exists()) { try { ExifInterface exif = new ExifInterface(picPath); String tagLat = exif .getAttribute(ExifInterface.TAG_GPS_LATITUDE); String tagLon = exif .getAttribute(ExifInterface.TAG_GPS_LONGITUDE); if (tagLat == null && tagLon == null) // 无经纬度信息 { exif.setAttribute(ExifInterface.TAG_GPS_LATITUDE, decimalToDMS(dLat)); exif.setAttribute(ExifInterface.TAG_GPS_LATITUDE_REF, dLat > 0 ? "N" : "S"); // 区分南北半球 exif.setAttribute(ExifInterface.TAG_GPS_LONGITUDE, decimalToDMS(dLon)); exif.setAttribute(ExifInterface.TAG_GPS_LONGITUDE_REF, dLon > 0 ? "E" : "W"); // 区分东经西经 exif.saveAttributes(); } } catch (Exception e) { } } }测试代码
String strImgPath = getImageCachePath() + File.separator + "1.jpg"; ExifInterface eif = new ExifInterface(strImgPath); String lat = eif.getAttribute(ExifInterface.TAG_GPS_LATITUDE); String latRef = eif.getAttribute(ExifInterface.TAG_GPS_LATITUDE_REF); String lon = eif.getAttribute(ExifInterface.TAG_GPS_LONGITUDE); String lonRef = eif.getAttribute(ExifInterface.TAG_GPS_LONGITUDE_REF); System.out.println("Latitude Ref - " + latRef); System.out.println("Latitude - " + lat); System.out.println("Longitude Ref - " + lonRef); System.out.println("Longitude - " + lon); if (lat == null && lon == null) // 没有位置信息才写入 { writeLatLonIntoJpeg(strImgPath, 39.23456, 116.123456); }第一次运行结果
05-22 17:36:24.566: I/System.out(17966): Latitude Ref - null05-22 17:36:24.566: I/System.out(17966): Latitude - null05-22 17:36:24.566: I/System.out(17966): Longitude Ref - null05-22 17:36:24.566: I/System.out(17966): Longitude - null
原始图片没有位置信息，通过调用writeLatLonIntoJpeg(strImgPath, 39.23456, 116.123456)来模拟写入一个位置。
第二次运行结果
05-22 17:37:11.446: I/System.out(17966): Latitude Ref - N05-22 17:37:11.446: I/System.out(17966): Latitude - 39/1,14/1,4/105-22 17:37:11.446: I/System.out(17966): Longitude Ref - E05-22 17:37:11.446: I/System.out(17966): Longitude - 116/1,7/1,24/1
参考：
http://blog.csdn.net/henry121212/article/details/17553719
http://blog.csdn.net/caiwenfeng_for_23/article/details/37706617