Chart.js在保持寬高比的同時更改窗口大小的高度

Question

我在調整chart.js畫布的大小時遇到​​了問題。 我已經將畫布高度設置為160，以便在更寬的屏幕上看起來很好，但我需要在小屏幕上將高度更改為300，這樣在保持其寬高比時看起來不會顯得狹窄。

此外，我想在條形圖上添加一個onclick事件，這會導致鏈接通過其各自標簽的月份。

非常感謝這里是我的代碼

<div>
<canvas id="chart1" width="500" height="300"></canvas>
</div>

<script>
var barLabel = <?php echo json_encode(array_reverse( $ch1_arrDate)); ?>;
var dataVal1 = <?php echo json_encode(array_reverse( $ch1_arrRevenue_conf)); ?>;
var barData = {
    labels: barLabel,
    datasets: [
        {
            label: 'Confirmed Revenue',
            backgroundColor: 'yellowgreen',
            data: dataVal1,

        },
    ]
};

var barOptions = { 
    responsive: true,
    maintainAspectRatio: true
}

var ctx = document.getElementById("chart1").getContext("2d");

if($(window).width()>748)
    ctx.canvas.height = 160;
else
    ctx.canvas.height = 300;

var chartDisplay = new Chart(ctx, {
    type: 'bar',
    data: barData,
    options: barOptions
});

$("#chart1").click( 
    function(evt){

    //supposed to when clicked goes to a linked href passing the month of the selected bar
    // e.g dummy.php?month_year=vardate
});

window.onresize = function() {

//the window.onresize works but i dont know how to resize the canvas while maintaining the aspect ratio.
if($(window).width()>748)
    ctx.canvas.height = 160; 
else
    ctx.canvas.height = 300;

chartDisplay.resize();
}
</script>

條狀圖

Answer 1

我找到了一種方法來重新調整圖表的大小，再次加載它以刷新新的高度，這可能不是最好的做法。 還找到了一種鏈接每個欄並將參數發送到另一個頁面的方法。 看下面的代碼。

在我的dashboard.php中：

<script>
window.onresize=function(){
    $("#container").load("chart1.php");
}

$("#container").load("chart1.php");
</script>

在chart1.php中：

<?php
//myqueries here for $ch1_arrDate,$ch1_arrRevenue_conf, and $ch1_arrDate2
?>
<div>
    <canvas id="chart1" width="500" height="300"></canvas>
</div>


<script>
$(document).ready(function(){
var barLabel = <?php echo json_encode(array_reverse( $ch1_arrDate)); ?>;
var dataVal1 = <?php echo json_encode(array_reverse( $ch1_arrRevenue_conf)); ?>;
var dateFilter = <?php echo json_encode(array_reverse($ch1_arrDate2)); ?>;

var barData = {
    labels: barLabel,
    datasets: [
        {
            label: 'Confirmed Revenue',
            backgroundColor: 'yellowgreen',
            data: dataVal1,
        },
    ]
};

var barOptions = { 
    responsive: true,
    maintainAspectRatio: true
}


var ctx = document.getElementById("chart1").getContext("2d");

if($(window).width()>748)
    ctx.canvas.height = 160;
else
    ctx.canvas.height = 300;

var chartDisplay = new Chart(ctx, {
    type: 'bar',
    data: barData,
    options: barOptions
});

$("#chart1").click( 
   function(e){
        var activeBars = chartDisplay.getElementsAtEvent(e);
        var index = activeBars[0]["_index"];
        location.href="dash_chartdeals.php?filter_date="+fixedEncodeURIComponent(dateFilter[index]);
});
});
</script>