D3 v4只需缩放到中心 [英] D3 v4 ajust zoom to center
本文介绍了D3 v4只需缩放到中心的处理方法，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
是否有明显的d3 V4等效于V3 d3.behavior.zoom（）
Is there an obvious d3 V4 equivalent to the V3 d3.behavior.zoom()
.center（[width / 2，height / 2]）语法。
.center([width / 2, height / 2]) syntax.
（我已经四处搜索了，手动缩放的大多数工作示例等都在V3中运行......而且API文档中没有提及它我能说得最好。）
(I've searched around, and most working examples of manual zooming etc run in V3... and the API docs don't mention it as best I can tell. )
我试图添加手动的缩放/按钮，使用示例：
I am trying to add manual zoomin/out buttons, using the example:
https://bl.ocks.org/mbostock/7ec977c95910dd026812 作为基础，但使用V4。
https://bl.ocks.org/mbostock/7ec977c95910dd026812 as a base, but with V4.
Harpal 给我看一个在d3 v4中工作的示例，但我不知道如何适用于我项目。
Harpal show me an example working in d3 v4, but i dont know how apply to my project.
所以有我的剧本：
//-----------------------------------Variables ---------------------------------------------------------------------------
//Alto y ancho
var w = 500;
var h = 500;
var padding = 0;
var coundata= 0;
var maxx = 0.30
var minx = -0.30
var maxy = 6
var miny = -6
//-----------------------------------CREAR GRAFICO SCATTER ----------------------------------------------------------------
//Funciones de escala
var xScale = d3.scaleLinear()
.domain([minx, maxx])
.range([padding, h]);
var yScale = d3.scaleLinear()
.domain([miny, maxy])
.range([h, padding]);
var rScale = d3.scaleLinear()
.domain([0,5])
.range([2, 6]);
//Eje x
var xAxis = d3.axisBottom()
.scale(xScale);;
//Eje y
var yAxis = d3.axisLeft()
.scale(yScale);
//Crear el elemento svg
var svg = d3.select("#linegraph")
.append("svg")
.attr("width", w)
.attr("height", h);
//Colores
grupo = svg.append("svg:g");
var c2 = grupo.append("rect")
.attr("width", (w/2) - padding)
.attr("height", (h/2)- padding)
.attr("transform", "translate("+w/2+","+padding+")")
.attr("fill", "rgba(0, 255, 0, 0.3)");
var c1 = grupo.append("rect")
.attr("width", (w/2) - padding)
.attr("height", (h/2)- padding)
.attr("transform", "translate("+padding+","+padding+")")
.attr("fill", "rgba(255, 255, 0, 0.3)");
var c3 = grupo.append("rect")
.attr("width", (w/2) - padding)
.attr("height", (h/2)- padding)
.attr("transform", "translate("+padding+","+h/2+")")
.attr("fill", "rgba(255, 0, 0, 0.3)");
var c4 = grupo.append("rect")
.attr("width", (w/2) - padding)
.attr("height", (h/2)- padding)
.attr("transform", "translate("+w/2+","+h/2+")")
.attr("fill", "rgba(255, 165, 0, 0.3)");
var g =svg.append("g");
//Añadimos el eje x
var gX = svg.append("g")
.attr("class", "axis")
.attr("transform", "translate(0," + (h/2) + ")")
.call(xAxis);
//Añadimos el eje y
var gY = svg.append("g")
.attr("class", "axis")
.attr("transform", "translate(" + (w/2) + ",0)")
.call(yAxis);
nowData = []
var grupo2 = svg.append("svg:g");
//Creamos los puntos
var datos = grupo2.selectAll("circle")
.data(nowData)
.enter()
.append("circle")
.attr("cx", function(d) {
return xScale(d[0]);
})
.attr("cy", function(d) {
return yScale(d[1]);
})
.attr("r", function(d) {
return 5;
})
.append("svg:title")
.text(function(d) {return "Valor x: "+d[0] +"\n Valor y :"+d[1]; })
;
var grupoLineas = svg.append("svg:g");
//--------------------------------- ZOOM---------------------------------------------------------------------
var zoom = d3.zoom()
// Don’t allow the zoomed area to be bigger than the viewport.
.scaleExtent([1, Infinity])
.translateExtent([[0, 0], [w, h]])
.extent([[0, 0], [w, h]])
.on("zoom", zoomed);
grupo.style("transform-origin","50% 50% 0");
grupo2.style("transform-origin","50% 50% 0");
grupoLineas.style("transform-origin","50% 50% 0");
svg.style("transform-origin","50% 50% 0");
gX.style("transform-origin","50% 50% 0");
gY.style("transform-origin","50% 50% 0");
svg.call(zoom);
function zoomed() {
svg.attr("transform", d3.event.transform);
gX.call(xAxis.scale(d3.event.transform.rescaleX(xScale)));
gY.call(yAxis.scale(d3.event.transform.rescaleY(yScale)));
grupo2.attr("transform",d3.event.transform);
grupoLineas.attr("transform",d3.event.transform);
grupo.attr("transform",d3.event.transform);
}
function resetted() {
svg.transition()
.duration(750)
.call(zoom.transform, d3.zoomIdentity);
}
d3.select("#zoom_in")
.on("click",function(){
zoom.scaleBy(svg, 2);
})
d3.select("#zoom_out")
.on("click",function(){
zoom.scaleBy(svg, 0.5);
})
//---------------------------------------Funcion mostrarDatos ----------------------------------------------------------
function mostrarDatos(){
nowData=[]
grupo2.selectAll("circle")
.data(nowData)
.exit()
.remove()
if($("#eae").prop('checked') == true)
{
nowData.push(eaepunt1[coundata])
grupo2.selectAll("circle")
}
if($("#arab").prop('checked') == true)
{
nowData.push(arabpunt1[coundata])
}
console.log(nowData)
grupo2.selectAll("circle")
.data(nowData)
.enter()
.append("circle")
.attr("cx", function(d) {
return xScale(d[0]);
})
.attr("cy", function(d) {
return yScale(d[1]);
})
.attr("r", function(d) {
return 5;
})
.append("svg:title")
.text(function(d) {return "Valor x: "+d[0] +"\n Valor y :"+d[1]; })
;
}
$("#eae").change(function()
{
mostrarDatos();
});
$("#arab").change(function()
{
mostrarDatos()
});
我应用（transform-origin，50％50％ 0）; 但它无法正常工作
I apply the ("transform-origin","50% 50% 0"); but it not works correctly
推荐答案
你可以做2件事
-
首先，直接将缩放应用于中心：
First, apply zoom directly to center:
var zoom = d3.zoom()
// Don’t allow the zoomed area to be bigger than the viewport.
.scaleExtent([1, Infinity])
.translateExtent([[0, 0], [w, h]])
.extent([[0, 0], [w, h]])
.on("zoom", zoomed);
grupopadre.style("transform-origin", "50% 50% 0");
svg.call(zoom);
function zoomed() {
grupopadre
.style('transform', 'scale(' + d3.event.transform.k + ')');
}
其次，缩小时将图形居中：
Second, center the graphic when you zoom out:
var zoom = d3.zoom()
// Don’t allow the zoomed area to be bigger than the viewport.
.scaleExtent([1, Infinity])
.translateExtent([[0, 0], [w, h]])
.extent([[0, 0], [w, h]])
.on("zoom", zoomed);
grupopadre.style("transform-origin", "50% 50% 0");
svg.call(zoom);
function zoomed() {
grupopadre.attr("transform",d3.event.transform);
}
您需要创建一个包含所有svg内容的组。
You need create a group with all svg content in this.
这篇关于D3 v4只需缩放到中心的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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