我有一个使用html2canvas的功能来下载一些div作为图像。我希望能够在保存图像时在图像顶部添加一个标题,即chartColumnID。
function saveAsImage(chartColumnID){
html2canvas($('#'+ chartColumnID),
{
onrendered: function (canvas) {
var a = document.createElement('a');
a.href = canvas.toDataURL("image/png");
a.download = chartColumnID;
a.click();
}
});
};
我已经尝试过类似的方法,但是它不起作用,没有标题出现。我把a.text =移到了不同的行以再次检查我是否将其放在错误的位置但没有运气。
function saveAsImage(chartColumnID){
html2canvas($('#'+ chartColumnID),
{
onrendered: function (canvas) {
var a = document.createElement('a');
a.href = canvas.toDataURL("image/png");
a.download = chartColumnID;
a.text= (15, 15, chartColumnID.replace(/([A-Z])/g, ' $1').trim());
a.click();
}
});
};
有人知道如何使图表列ID成为标题吗?
答案 0 :(得分:1)
您可以尝试在画布上绘制文本(我没有检查过):
function saveAsImage(chartColumnID) {
html2canvas($('#' + chartColumnID), {
onrendered: function(canvas) {
// ----------------------------- here we draw text:
const fontHeight = 14;
const text = String(chartColumnID);
const ctx = canvas.getContext("2d");
ctx.font = fontHeight + "px Arial";
ctx.textAlign = "left";
ctx.fillStyle = "red"; // text color
ctx.fillText(text, 0, fontHeight);
// ------------------------------ your code as ususal:
var a = document.createElement('a');
a.href = canvas.toDataURL("image/png");
a.download = chartColumnID;
a.click();
}
});
};
在画布上的外观示例:
var canvas = document.getElementById("c");
var chartColumnID = (Math.random() * 1000 + 1) | 0;
canvas.width = 100;
canvas.height = 100;
const fontHeight = 14;
const text = String(chartColumnID);
const ctx = canvas.getContext("2d");
ctx.font = fontHeight + "px Arial";
ctx.textAlign = "left";
ctx.fillStyle = "red"; // text color
ctx.fillText(text, 0, fontHeight);
canvas { border: 1px solid }
<canvas id="c" />