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javascript - 如何使用javascript动态获取和设置SVG元素的ID

问题描述

所以我想设置并获取我创建的 SVG 元素的 ID。当我尝试使用 document.getElementByID() 获取 SVG 元素时，我这样做的方式不起作用。我的主要目标是最终实现一种方式，让我可以看到哪个元素被拖到另一个元素的顶部，以便我可以相应地更改形状的颜色。任何帮助表示赞赏，谢谢。

const SVG_NS = 'http://www.w3.org/2000/svg';

let Y = 1450;



// create bottom left row
for(let i = 1; i< 12; i++){
  let x = 21 + i*49;
  drawCircle({cx:x, cy:Y,r:20},circle_seats,i);
  drawText({props:{x:x, y:Y},txtContent:i}, circle_seats);
  
}


// create bottom right row
for(i = 12; i < 23; i++) {
  let x = 21 + i*49;
  drawCircle({cx:(x+49*5), cy:Y,r:20},circle_seats,i);
  drawText({props:{x:(x+49*5), y:Y},txtContent:i}, circle_seats);
}
Y = 1400;

//create top left row
for(let i = 1,j = 23; i< 15; i++,j++){
  let x = 21 + i*49;
  drawCircle({cx:x, cy:Y,r:20},circle_seats,i);
  drawText({props:{x:x, y:Y},txtContent:j}, circle_seats);
  
}

//create top right row
for(i = 12,j = 37; i < 27; i++,j++) {
  let x = 21 + i*49;
  drawCircle({cx:(x+49*5), cy:Y,r:20},circle_seats,i);
  drawText({props:{x:(x+49*5), y:Y},txtContent:j}, circle_seats);
}

function drawCircle(o, parent, a) {

  var circle = document.createElementNS(SVG_NS, 'circle');
  for (var name in o) {
    if (o.hasOwnProperty(name)) {
      circle.setAttributeNS(null, name, o[name]);
      circle.id = "seat"+ a;
    }
  }
  parent.appendChild(circle);
  return circle;
}

function drawText(o, parent) {
  var text = document.createElementNS(SVG_NS, "text");
  for (var name in o.props) {
    if (o.props.hasOwnProperty(name)) {
      text.setAttributeNS(null, name, o.props[name]);
    }
  }
  text.textContent = o.txtContent;
  parent.appendChild(text);
  return text;
}
//rectangle plate functions

function drawText_plate(o, parent) {
  var text = document.createElementNS(SVG_NS, "text");
  for (var name in o.props) {
    if (o.props.hasOwnProperty(name)) {
      text.setAttributeNS(null, name, o.props[name]);
    }
  }
  text.textContent = o.txtContent;
  text.style.fontSize = "17px";
  parent.appendChild(text);
  return text;
}




var svgns = "http://www.w3.org/2000/svg";
function drawRectangle(o, parent, a) {
  var rectangle = document.createElementNS(svgns, 'rect');
  for (var name in o) {
    if (o.hasOwnProperty(name)) {
      rectangle.setAttributeNS(null, name, o[name]);
      rectangle.setAttribute("id", "seat"+ a);
    }
  }
  parent.appendChild(rectangle);
  return rectangle;
}



Y = 100;
let X = 25;
  drawRectangle({x:X, y:Y,width:100,height:50},name_plates,i);
  drawText_plate({props:{x:X+90, y:Y+25},txtContent:1}, name_plates);
  drawCircle({cx:X+10,cy:Y+25,r:5},name_plates,1);
  
  
for(let i = 2; i< 51; i++){
  X = X + 100 + 10
  if(i % 13 == 0) {
    X = 25;
    Y = Y + 55;
  }
  drawRectangle({x:X, y:Y,width:100,height:50},name_plates,i);
  drawText_plate({props:{x:X+90, y:Y+25},txtContent:i}, name_plates);
  drawCircle({cx:X+10,cy:Y+25,r:5},name_plates,i);
  
  
}


//NameTag Functions

function drawText_name_tag(o, parent) {
  var text = document.createElementNS(SVG_NS, "text");
  for (var name in o.props) {
    if (o.props.hasOwnProperty(name)) {
      text.setAttributeNS(null, name, o.props[name]);
    }
  }
  text.textContent = o.txtContent;
  text.style.fontSize = "10px";
  parent.appendChild(text);
  return text;
}

//create name tags
Y = 400;
X = 25;
  drawRectangle({x:X, y:Y,width:100,height:50},name_tags,i);
  drawText_name_tag({props:{x:X+50, y:Y+25},txtContent:"BLANK"}, name_tags);

for(let i = 2; i< 2; i++){
  X = X + 100 + 10
  if(i % 13 == 0) {
    X = 25;
    Y = Y + 55;
  }
  drawRectangle({x:X, y:Y,width:100,height:50},name_tags,i);
  drawText_name_tag({props:{x:X+50, y:Y+25},txtContent:"BLANK"}, name_tags);
  
  
  
}


function change_name(event) {
	var name = prompt("Enter a New Name (Max 20 characters):");
	while(name.length > 20) {
    name = prompt("Enter a New Name (Previous Over 20 Characters)");
  }
  if (name != null && name != "") {
event.target.textContent = name;
	}
}
text {
  fill: black;
  font-family: Verdana;
  font-size: 28px;
  stroke: black;
  dominant-baseline:middle;
  text-anchor:middle;
}

circle {
  fill: url(#gradGreen);
  stroke: black;
}

rect {
  fill: url(#gradGrey);
  stroke: black;
}
<svg id="svg" height="1500" width="1500">
	<defs>
		<lineargradient id="gradGreen" x1="0%" x2="100%" y1="0%" y2="0%">
			<stop offset="0%" style="stop-color:rgb(152, 251, 152);stop-opacity:1"></stop>
			<stop offset="100%" style="stop-color:rgb(0, 128, 0);stop-opacity:1"></stop>
		</lineargradient>
		<lineargradient id="gradYellow" x1="0%" x2="100%" y1="0%" y2="0%">
			<stop offset="0%" style="stop-color:rgb(255, 140, 0);stop-opacity:1"></stop>
			<stop offset="100%" style="stop-color:rgb(218, 165, 32);stop-opacity:1"></stop>
		</lineargradient>
		<lineargradient id="gradRed" x1="0%" x2="100%" y1="0%" y2="0%">
			<stop offset="0%" style="stop-color:rgb(255, 0, 0);stop-opacity:1"></stop>
			<stop offset="100%" style="stop-color:rgb(178, 34, 34);stop-opacity:1"></stop>
		</lineargradient>
	<lineargradient id="gradGrey" x1="0%" x2="100%" y1="0%" y2="0%">
			<stop offset="0%" style="stop-color:rgb(220, 220, 220);stop-opacity:1"></stop>
			<stop offset="100%" style="stop-color:rgb(105, 105, 105);stop-opacity:1"></stop>
		</lineargradient>
  
  </defs>
  
  
	<g class="circle_seat" id="circle_seats">
		  
  </g>
  
  <g class ="name_plate" id= "name_plates">
  
  </g>
	
  
  
  
  <g class="name_tag" id="name_tags" ondblclick="change_name(event)">

	</g>

  
  </svg>

标签： javascripthtmlcsssvg

解决方案

为了画一个圆，你正在使用这个函数：

function drawCircle(o, parent) {

  var circle = document.createElementNS(SVG_NS, 'circle');
  for (var name in o) {
    if (o.hasOwnProperty(name)) {
      circle.setAttributeNS(null, name, o[name]);
      //circle.id = "seat"+ a;
    }
  }
  parent.appendChild(circle);
  return circle;
}

如您所见，我已经注释掉了一行代码，即您尝试设置 id 的代码。你不需要这条线。创建新圈子时，您可以：

drawCircle({cx:(x+49*5), 
            cy:Y,
            r:20,
            id:"seat"+i},circle_seats);

现在您的 id 已设置，您可以使用document.getElementByID().

更新

这是您的代码，但我删除了一些您不需要的功能。由于您不能重复ids，因此我通过添加trfor top left blfor bottom left... 而不是. 来命名它们seat。

这很重要：表示属性的特异性非常低，并且被 css 声明覆盖。要更改在 css 中设置的填充，您需要添加 css 规则：

document.getElementById("bl1").setAttribute("style", "fill:red");


const SVG_NS = "http://www.w3.org/2000/svg";

let Y = 1450;

// create bottom left row
for (let i = 1; i < 12; i++) {
  let x = 21 + i * 49;
  drawCircle({ cx: x, cy: Y, r: 20, id: "bl" + i }, circle_seats);
  drawText({ props: { x: x, y: Y }, txtContent: i }, circle_seats);
}

// create bottom right row
for (i = 12; i < 23; i++) {
  let x = 21 + i * 49;
  drawCircle({ cx: x + 49 * 5, cy: Y, r: 20, id: "br" + i }, circle_seats);
  drawText({ props: { x: x + 49 * 5, y: Y }, txtContent: i }, circle_seats);
}
Y = 1400;

//create top left row
for (let i = 1, j = 23; i < 15; i++, j++) {
  let x = 21 + i * 49;
  drawCircle({ cx: x, cy: Y, r: 20, id: "tl" + i }, circle_seats);
  drawText({ props: { x: x, y: Y }, txtContent: j }, circle_seats);
}

//create top right row
for (i = 12, j = 37; i < 27; i++, j++) {
  let x = 21 + i * 49;
  drawCircle({ cx: x + 49 * 5, cy: Y, r: 20, id: "tr" + i }, circle_seats);
  drawText({ props: { x: x + 49 * 5, y: Y }, txtContent: j }, circle_seats);
}

function drawCircle(o, parent) {
  var circle = document.createElementNS(SVG_NS, "circle");
  for (var name in o) {
    if (o.hasOwnProperty(name)) {
      circle.setAttributeNS(null, name, o[name]);
      //circle.id = "seat"+ a;
    }
  }
  parent.appendChild(circle);
  return circle;
}

function drawText(o, parent) {
  var text = document.createElementNS(SVG_NS, "text");
  for (var name in o.props) {
    if (o.props.hasOwnProperty(name)) {
      text.setAttributeNS(null, name, o.props[name]);
    }
  }
  text.textContent = o.txtContent;
  parent.appendChild(text);
  return text;
}

function drawRectangle(o, parent) {
  var rectangle = document.createElementNS(SVG_NS, "rect");
  for (var name in o) {
    if (o.hasOwnProperty(name)) {
      rectangle.setAttributeNS(null, name, o[name]);
      //rectangle.setAttribute("id", "seat"+ a);
    }
  }
  parent.appendChild(rectangle);
  return rectangle;
}

Y = 100;
let X = 25;
drawRectangle({ x: X, y: Y, width: 100, height: 50 }, name_plates, 1);
drawText({ props: { x: X + 90, y: Y + 25 }, txtContent: 1 }, name_plates);
drawCircle({ cx: X + 10, cy: Y + 25, r: 5 }, name_plates, 1);

for (let i = 2; i < 51; i++) {
  X = X + 100 + 10;
  if (i % 13 == 0) {
    X = 25;
    Y = Y + 55;
  }
  drawRectangle({ x: X, y: Y, width: 100, height: 50 }, name_plates, i);
  drawText({ props: { x: X + 90, y: Y + 25 }, txtContent: i }, name_plates);
  drawCircle({ cx: X + 10, cy: Y + 25, r: 5 }, name_plates, i);
}

//create name tags
Y = 400;
X = 25;
drawRectangle({ x: X, y: Y, width: 100, height: 50 }, name_tags);
drawText(
  { props: { x: X + 50, y: Y + 25, class: "blank" }, txtContent: "BLANK" },
  name_tags
);

document.getElementById("bl1").setAttribute("style", "fill:red");

function change_name(event) {
  var name = prompt("Enter a New Name (Max 20 characters):");
  while (name.length > 20) {
    name = prompt("Enter a New Name (Previous Over 20 Characters)");
  }
  if (name != null && name != "") {
    event.target.textContent = name;
  }
}
text {
  fill: black;
  font-family: Verdana;
  font-size: 28px;
  stroke: black;
  dominant-baseline:middle;
  text-anchor:middle;
}

#name_plates text{font-size:17px}
text.blank{font-size:10px}
circle {
  fill: url(#gradGreen);
  stroke: black;
}

rect {
  fill: url(#gradGrey);
  stroke: black;
}
<svg id="svg" viewBox="0 0 1500 1500">
	<defs>
		<lineargradient id="gradGreen" x1="0%" x2="100%" y1="0%" y2="0%">
			<stop offset="0%" style="stop-color:rgb(152, 251, 152);stop-opacity:1"></stop>
			<stop offset="100%" style="stop-color:rgb(0, 128, 0);stop-opacity:1"></stop>
		</lineargradient>
		<lineargradient id="gradYellow" x1="0%" x2="100%" y1="0%" y2="0%">
			<stop offset="0%" style="stop-color:rgb(255, 140, 0);stop-opacity:1"></stop>
			<stop offset="100%" style="stop-color:rgb(218, 165, 32);stop-opacity:1"></stop>
		</lineargradient>
		<lineargradient id="gradRed" x1="0%" x2="100%" y1="0%" y2="0%">
			<stop offset="0%" style="stop-color:rgb(255, 0, 0);stop-opacity:1"></stop>
			<stop offset="100%" style="stop-color:rgb(178, 34, 34);stop-opacity:1"></stop>
		</lineargradient>
	<lineargradient id="gradGrey" x1="0%" x2="100%" y1="0%" y2="0%">
			<stop offset="0%" style="stop-color:rgb(220, 220, 220);stop-opacity:1"></stop>
			<stop offset="100%" style="stop-color:rgb(105, 105, 105);stop-opacity:1"></stop>
		</lineargradient>
  
  </defs>
  
  
	<g class="circle_seat" id="circle_seats">
		  
  </g>
  
  <g class ="name_plate" id= "name_plates">
  
  </g>
	 <g class="name_tag" id="name_tags" onclick="change_name(event)">

	</g>

  
  </svg>

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