14

嗨 RaphaelJS 用户 =) ,

我可能有一个愚蠢的问题，但我似乎找不到答案，问题是，我正在尝试使用 Raphael 加载/创建图像，这很好，就像这样：

var image_1 = paper.image('/img/img1.jpg', 0, 0, 100, 100);

但是正如您所看到的，您似乎总是必须给出“宽度”和“高度”属性，我已经检查了文档，但它总是很短而且不是很详细，我尝试给出空参数或空参数，但是它不起作用...

所以我想知道拉斐尔是否真的有直接的方法可以做到这一点，或者....我之前是否必须始终获得这些值？？？

我的意思是，像这样的东西？：

var imgURL = "../img/img1.jpg"

var myImg = new Image();
myImg.src = imgURL;

var width = myImg.width;
var height = myImg.height;

   //create the image with the obtained width and height:
    var image_1 = paper.image('/img/img1.jpg', 0, 0, width, height);

这样我就可以加载图像的原始大小，这有点解决了我的问题，但是……Raphael内部没有办法做到这一点吗？

4

4 回答 4

15

现在......我想我必须用我自己的答案来回答我自己的问题，因为我似乎没有找到其他方法或者有人告诉我=P

var imgURL = "../img/img1.jpg"

var myImg = new Image();
myImg.src = imgURL;

var width = myImg.width;
var height = myImg.height;

   //create the image with the obtained width and height:
    var image_1 = paper.image('/img/img1.jpg', 0, 0, width, height);
于 2012-06-22T01:18:21.843 回答
9

基于@drzaus 的出色答案，我遇到了一些问题，如果我加载到 Raphael 中的图像尚未在缓存中，则高度和宽度将设置为 0。要解决此问题：

(function(Raphael){
/// Plugin - replaces original RaphaelJS .image constructor
/// with one that respects original dimensions.
/// Optional overrides for each dimension.
/// @drzaus @zaus
/// based on http://stackoverflow.com/questions/10802702/raphael-js-image-with-its-original-width-and-height-size
/// modified 13/08/2013 by @Huniku to support asynchronous loads

var originalRaphaelImageFn = Raphael.fn.image;

Raphael.fn.imageAsync = function(url, x, y, w, h) {
    var dfd = new jQuery.Deferred();
    var done = false;
    var paper = this;
    // fix the image dimensions to match original scale unless otherwise provided
    if( !w || !h ) {
        //Create the new image and set the onload event to call
        //the original paper.image function with the desired dimensions
        var img = new Image();
        img.onload = function() {
            if(done)
                return;
            if( !w ) w = img.width;
            if( !h ) h = img.height;
            dfd.resolve(originalRaphaelImageFn.call(paper, url, x, y, w, h));
        };
        //Begin loading of the image
        img.src = url;

        //If the images is already loaded (i.e. it was in the local cache)
        //img.onload will not fire, so call paper.image here.
        //Set done to ensure img.onload does not fire.
        if(img.width != 0) {
            if( !w ) w = img.width;
            if( !h ) h = img.height;
            done = true;
            dfd.resolve(originalRaphaelImageFn.call(paper, url, x, y, w, h));
        }
    }
    else
        dfd.resolve(originalRaphaelImageFn.call(paper, url, x, y, w, h));
    return dfd.promise();
};
})(Raphael);

这允许图像在查询宽度/高度之前加载，并且还支持图像已经在缓存中并且未触发 onload 事件的实例。要使用它，只需：

var dfd = paper.imageAsync("images/hello.png",0,0,false,false);
dfd.done(function( result ) {  //result is a Raphael element
    console.log('done');
    //do something with result
});
于 2013-08-14T00:11:28.167 回答
3

有同样的问题，谢谢你的提示——这是一个用尊重尺寸的插件替换现有图像功能的插件：http: //jsfiddle.net/drzaus/dhkh7/

为了更安全，可能不应该覆盖原始图像函数，以防万一它发生变化，但你明白了。

;(function(Raphael){
/// Plugin - replaces original RaphaelJS .image constructor
/// with one that respects original dimensions.
/// Optional overrides for each dimension.
/// @drzaus @zaus
/// based on http://stackoverflow.com/questions/10802702/raphael-js-image-with-its-original-width-and-height-size

var originalRaphaelImageFn = Raphael.fn.image;
Raphael.fn.image = function(url, x, y, w, h) {
    // fix the image dimensions to match original scale unless otherwise provided
    if( !w || !h ) {
        var img = new Image();
        img.src = url;
        if( !w ) w = img.width;
        if( !h ) h = img.height;
    }
    return originalRaphaelImageFn.call(this, url, x, y, w, h);
};
})(Raphael);

和用法：

window.onload = function() {
  var paper = new Raphael('canvas', '100%', '100%');

  // specify dimensions as before
  paper.image('http://www.stockfreeimages.com/Swiss-panorama-thumb6499792.jpg', 10, 10, 100, 50).attr('stroke', '#000');

  // original ratio
  paper.image('http://www.stockfreeimages.com/Swiss-panorama-thumb6499792.jpg', 10, 100).attr('stroke', '#f00');

  // specify width, height taken from original
  paper.image('http://www.stockfreeimages.com/Swiss-panorama-thumb6499792.jpg', 10, 200, 100).attr('stroke', '#0f0');

  // specify height, width taken from original
  paper.image('http://www.stockfreeimages.com/Swiss-panorama-thumb6499792.jpg', 10, 300, false, 100).attr('stroke', '#00f');
};
于 2013-01-12T15:42:05.663 回答
0

爱德华的评论对我有用，但我必须将它放在一个区间函数中，并等到定义宽度和高度后再添加图像（否则我得到一个 0x0 图像）。这是我使用的代码：

var imgURL = "/img/img1.jpg"
var myImg = new Image();
myImg.src = imgURL;

function loadImagAfterWidthAndHeightAreDefined(){
  width = myImg.width;
  height = myImg.height;

  if(myImg.width > 0 && myImg.height > 0){
    image_1 = paper.image(imgURL, 0, 0, width, height);
  }
  else{
    setTimeout(function(){
      loadImagAfterWidthAndHeightAreDefined();
    },250);
  }
}
loadImagAfterWidthAndHeightAreDefined()
于 2014-12-18T09:49:49.870 回答