使用JSON文件绘制到画布 [英] Drawing to canvas using JSON file
本文介绍了使用JSON文件绘制到画布的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在尝试使用Ajax将json对象中的行信息调用到画布中.我是json的新手，所以我不完全确定该怎么做.这就是我到目前为止所拥有的.
I am trying to call line info from a json object into a canvas using ajax. I'm new to json, so I'm not entirely sure how to go about doing this. Here's what I have so far.
JSON
{
"line": {
"width": 3,
"stroke": "#FFFFFF",
"x1": "640.386",
"y1": "258.163",
"x2": "816.364",
"y2": "258.163"
}
}
JS
$(document).ready(function(){
var canvas = document.getElementById("schematic_holder");
var ctx = canvas.getContext("2d");
$.ajax({
type: "GET",
dataType: "json",
url: "js/app/json/nst.json",
success: function(result){
$.each(result.line, function(){
console.log(result.line);
})
},
complete: function(){
console.log("Complete!");
}
})
})
HTML
<body>
<canvas id="schematic_holder"></canvas>
</body>
现在，当我打印到控制台时，出现一个未定义的错误.我称这个对象不对吗?我知道如何用画布绘制线条，我只是对如何从JSOn文件中绘制线条感到困惑.预先感谢.
Right now, when I print to the console, I'm getting an undefined error. Am I calling the object wrong? I know how to get the lines to draw with canvas, I'm just confused about how to do so from a JSOn file. Thanks in advance.
推荐答案
尝试将整个json文件包装在方括号[]中，就像这样
Try wrapping the entire json file in brackets [], like this
[{
"line": {
"width": 3,
"stroke": "#FFFFFF",
"x1": "640.386",
"y1": "258.163",
"x2": "816.364",
"y2": "258.163"
}
}]
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