我制作了一个相当大的脚本，可以检测用户使用浏览器地理位置功能的地理区域，然后更改背景图像并将其淡入标题。
现在它是一系列条件if / else if语句。效果很好，但只是代码开始变得相当大。
<script type = "text/javascript" >
var geoHeader = document.getElementById("geozones");
function locate() {
if (navigator.geolocation) {
console.log('getting geolocation information...');
navigator.geolocation.getCurrentPosition(function (position) {
// Determine if in brisbane
if (position.coords.latitude >= -27.936539 && position.coords.latitude <= -26.772950 && position.coords.longitude >= 152.439692 && position.coords.longitude <= 153.543818) {
geoHeader.style.backgroundImage = 'url(http://testing.slq.qld.gov.au/__data/assets/image/0004/315409/gelocation-selection-Enlisting-depot-in-Brisbane-during-World-War-I.jpg)';
geoHeader.className = geoHeader.className + " fadeHeader";
geoHeader.style.opacity = '1';
console.log('You might be in Brisbane');
//Determine if in Barcaldine
} else if (position.coords.latitude >= -23.741146 && position.coords.latitude <= -23.450440 && position.coords.longitude >= 145.117460 && position.coords.longitude <= 145.484472) {
geoHeader.style.backgroundImage = 'url(http://i1167.photobucket.com/albums/q640/coolwebs/barcaldine-pub_zpsf8oazwr8.jpg)';
geoHeader.className = geoHeader.className + " fadeHeader";
geoHeader.style.opacity = '1';
console.log('You might be in Barcaldine');
//Determine if in Beerburrum boundaries
} else if (position.coords.latitude >= -26.998834 && position.coords.latitude <= -26.892941 && position.coords.longitude >= 143.313919 && position.coords.longitude <= 153.01622) {
geoHeader.style.backgroundImage = 'url(http://testing.slq.qld.gov.au/__data/assets/image/0016/315421/gelocation-selection-View-of-Beerburrum-showing-the-hospital-building-on-the-hill-and-houses-in-the-street-ca-1921.jpg)';
geoHeader.className = geoHeader.className + " fadeHeader";
geoHeader.style.opacity = '1';
console.log('You might be in Beerburrum');
//Determine if in Biggenden boundaries
} else if (position.coords.latitude >= -25.743886 && position.coords.latitude <= -25.173518 && position.coords.longitude >= 151.750732 && position.coords.longitude <= 152.365966) {
geoHeader.style.backgroundImage = 'url(http://testing.slq.qld.gov.au/__data/assets/image/0017/315422/gelocation-selection-Woman-seated-in-a-Red-Cross-ambulance-Biggenden-19141918.jpg)';
geoHeader.className = geoHeader.className + " fadeHeader";
geoHeader.style.opacity = '1';
console.log('You might be in Biggenden');
//Find out Charleville boundaries
} else if (position.coords.latitude >= -26.735435 && position.coords.latitude <= -25.982371 && position.coords.longitude >= 145.503569 && position.coords.longitude <= 146.679106) {
geoHeader.style.backgroundImage = 'url(http://testing.slq.qld.gov.au/__data/assets/image/0004/315418/gelocation-selection-Red-Cross-workers-Charleville-1914.jpg)';
geoHeader.className = geoHeader.className + " fadeHeader";
console.log('You might be in Barcaldine');
//Determine if in Chinchilla boundaries
} else if (position.coords.latitude >= -27.016575 && position.coords.latitude <= -26.504023 && position.coords.longitude >= 150.383621 && position.coords.longitude <= 150.913711) {
geoHeader.style.backgroundImage = 'url(http://testing.slq.qld.gov.au/__data/assets/image/0005/315419/gelocation-selection-Returned-soldiers-in-uniform-surrounding-the-Digger-War-Memorial-in-Chinchilla-ca.-1920.jpg)';
geoHeader.className = geoHeader.className + " fadeHeader";
geoHeader.style.opacity = '1';
console.log('You might be in Chinchilla');
//Determine if in Cairns boundaries
} else if (position.coords.latitude >= -17.216314 && position.coords.latitude <= -16.619826 && position.coords.longitude >= 145.477123 && position.coords.longitude <= 146.013393) {
geoHeader.style.backgroundImage = 'url(http://i1167.photobucket.com/albums/q640/coolwebs/forms%20radio%20images/rex-lookout_zpsgnn4j1xx.jpg)';
geoHeader.className = geoHeader.className + " fadeHeader";
console.log('You might be in Cairns');
//Determine if in Lockyer Valley (Gatton and Helidon) boundaries
} else if (position.coords.latitude >= -27.774956 && position.coords.latitude <= 27.422018 && position.coords.longitude >= 152.03981 && position.coords.longitude <= 152.495742) {
geoHeader.style.backgroundImage = 'url(http://testing.slq.qld.gov.au/__data/assets/image/0014/315410/gelocation-selection-Gatton-Mens-Auzzillary.jpg)';
geoHeader.className = geoHeader.className + " fadeHeader";
geoHeader.style.opacity = '1';
console.log('You might be in Lockyer Valley');
//Determine if in Rockhampton
} else if (position.coords.latitude >= -23.86413 && position.coords.latitude <= -22.348442 && position.coords.longitude >= 149.443603 && position.coords.longitude <= 150.783935) {
geoHeader.style.backgroundImage = 'url(http://testing.slq.qld.gov.au/__data/assets/image/0018/315414/gelocation-selection-March-to-Freedom-Column-at-Rockhampton-Queensland.jpg)';
geoHeader.className = geoHeader.className + " fadeHeader";
geoHeader.style.opacity = '1';
console.log('You might be in Rockhampton');
//Determine if in Sunshine Coast (Buderim and Maleny) boundaries
} else if (position.coords.latitude >= -26.862318 && position.coords.latitude <= -26.312145 && position.coords.longitude >= 152.807479 && position.coords.longitude <= 153.172775) {
geoHeader.style.backgroundImage = 'url(http://testing.slq.qld.gov.au/__data/assets/image/0020/315416/gelocation-selection-Parade-in-Maleny-ca.-1915.jpg)';
geoHeader.className = geoHeader.className + " fadeHeader";
geoHeader.style.opacity = '1';
console.log('You might be in Sunshine Coast');
//Determine if in Thargomindah boundaries
} else if (position.coords.latitude >= -28.378369 && position.coords.latitude <= -27.529237 && position.coords.longitude >= 143.313919 && position.coords.longitude <= 144.478469) {
geoHeader.style.backgroundImage = 'url(http://testing.slq.qld.gov.au/__data/assets/image/0015/315420/gelocation-selection-Selling-flowers-to-raise-funds-for-the-Red-Cross-Thargomindah-ca.-1916.jpg)';
geoHeader.className = geoHeader.className + " fadeHeader";
geoHeader.style.opacity = '1';
console.log('You might be in Thargomindah');
//Determine if in Toogoolawah (in the Brisbane Valley) boundaries
} else if (position.coords.latitude >= -27.402512 && position.coords.latitude <= -26.91376 && position.coords.longitude >= 152.210098 && position.coords.longitude <= 152.715469) {
geoHeader.style.backgroundImage = 'url(http://testing.slq.qld.gov.au/__data/assets/image/0003/315417/gelocation-selection-Peace-celebrations-in-Toogoolawah-1918.jpg)';
geoHeader.className = geoHeader.className + " fadeHeader";
geoHeader.style.opacity = '1';
console.log('You might be in Toogoolawah');
//Determine if in Townsville boundaries
} else if (position.coords.latitude >= -20.116181 && position.coords.latitude <= -18.363276 && position.coords.longitude >= 144.093261 && position.coords.longitude <= 147.619873) {
geoHeader.style.backgroundImage = 'url(http://testing.slq.qld.gov.au/__data/assets/image/0019/315415/gelocation-selection-Members-of-the-Mens-Auxiliary-at-Townsville-Queensland.jpg)';
geoHeader.className = geoHeader.className + " fadeHeader";
geoHeader.style.opacity = '1';
console.log('You might be in Townsville');
} else {
geoHeader.style.backgroundImage = 'url(http://i415.photobucket.com/albums/pp236/Keefers_/Keffers%20Animals/evilmonkey.jpg)';
geoHeader.className = geoHeader.className + " fadeHeader";
geoHeader.style.opacity = '1';
console.log('We dunno where you are... evil monkey is watching you');
}
}, function () {
geoHeader.style.opacity = '1';
geoHeader.style.backgroundImage = 'url(http://i636.photobucket.com/albums/uu82/fireduptiger/Enchanted%20Forest/untitled.jpg)';
geoHeader.className = geoHeader.className + " fadeHeader";
geoHeader.style.opacity = '1';
console.log('Too bad you are denying us your location. We are lost in the woods...');
});
} else {
console.log('error message. Geolocation failed. Probably lacking browser support' + error.code);
}
};
locate();
</script>
为了使脚本更小，我想通过循环脚本运行它并使用一系列数组来保存数据并循环遍历它。我只是担心在评估大量地理定位数据时会有点棘手 - 其他一切都很简单。
我很想知道这些建议。
答案 0 :(得分：2)
您可以将所有标题存储在对象中，包括：
这样的事情：
var headers = {
regional : [
{
desc : "Brisbane",
minLat : -27.936539,
maxLat : -26.772950,
minLong : 152.439692,
maxLong : 153.543818,
image : 'http://testing.slq.qld.gov.au/__data/assets/image/0004/315409/gelocation-selection-Enlisting-depot-in-Brisbane-during-World-War-I.jpg'
}, {
desc : "Barcaldine",
minLat : -23.741146,
maxLat : -23.450440,
minLong : 145.117460,
maxLong : 145.484472,
image : 'http://i1167.photobucket.com/albums/q640/coolwebs/barcaldine-pub_zpsf8oazwr8.jpg'
}
],
def : 'http://testing.slq.qld.gov.au/__data/assets/image/0004/315409/gelocation-selection-Enlisting-depot-in-Brisbane-during-World-War-I.jpg',
disabled : 'http://i636.photobucket.com/albums/uu82/fireduptiger/Enchanted%20Forest/untitled.jpg'
};
编写一个函数，它将遍历数组查找特定区域，如果找不到则返回默认值：
function getHeaderForCoordinates(lat, lng) {
for (var i = 0; i < headers.regional.length; i++)
{
var header = headers.regional[i];
if (lat >= header.minLat && lat <= header.maxLat
&& lng >= header.minLong && lng <= header.maxLong)
{
console.log("User is from " + header.desc);
return header.image;
}
}
console.log("User has geolocation, but region is unknown");
return headers.def;
}
然后，您将能够以这种方式在代码中使用它：
function wrapWithUrl(url) { // just an utility function
return "url('" + url + "')";
}
navigator.geolocation.getCurrentPosition(function (position) {
var url = getHeaderForCoordinates(position.coords.latitude, position.coords.longitude);
getHeader.style.backgroundImage = wrapWithUrl(url);
}, function () {
geoHeader.style.backgroundImage = wrapWithUrl(headers.disabled);
});