我知道这个问题已经在这里了，但我认为它没有得到正确的回答。到目前为止，我正在使用这种方法 100% 可以正常工作，对于我必须走的任何 Plot。
请评论代码的效率等，我想知道它是否还有错误。
非常感谢。
function jqplotToImg(obj) {
var newCanvas = document.createElement("canvas");
newCanvas.width = obj.find("canvas.jqplot-base-canvas").width();
newCanvas.height = obj.find("canvas.jqplot-base-canvas").height()+10;
var baseOffset = obj.find("canvas.jqplot-base-canvas").offset();
// make white background for pasting
var context = newCanvas.getContext("2d");
context.fillStyle = "rgba(255,255,255,1)";
context.fillRect(0, 0, newCanvas.width, newCanvas.height);
obj.children().each(function () {
// for the div's with the X and Y axis
if ($(this)[0].tagName.toLowerCase() == 'div') {
// X axis is built with canvas
$(this).children("canvas").each(function() {
var offset = $(this).offset();
newCanvas.getContext("2d").drawImage(this,
offset.left - baseOffset.left,
offset.top - baseOffset.top
);
});
// Y axis got div inside, so we get the text and draw it on the canvas
$(this).children("div").each(function() {
var offset = $(this).offset();
var context = newCanvas.getContext("2d");
context.font = $(this).css('font-style') + " " + $(this).css('font-size') + " " + $(this).css('font-family');
context.fillStyle = $(this).css('color');
context.fillText($(this).text(),
offset.left - baseOffset.left,
offset.top - baseOffset.top + $(this).height()
);
});
} else if($(this)[0].tagName.toLowerCase() == 'canvas') {
// all other canvas from the chart
var offset = $(this).offset();
newCanvas.getContext("2d").drawImage(this,
offset.left - baseOffset.left,
offset.top - baseOffset.top
);
}
});
// add the point labels
obj.children(".jqplot-point-label").each(function() {
var offset = $(this).offset();
var context = newCanvas.getContext("2d");
context.font = $(this).css('font-style') + " " + $(this).css('font-size') + " " + $(this).css('font-family');
context.fillStyle = $(this).css('color');
context.fillText($(this).text(),
offset.left - baseOffset.left,
offset.top - baseOffset.top + $(this).height()*3/4
);
});
// add the title
obj.children("div.jqplot-title").each(function() {
var offset = $(this).offset();
var context = newCanvas.getContext("2d");
context.font = $(this).css('font-style') + " " + $(this).css('font-size') + " " + $(this).css('font-family');
context.textAlign = $(this).css('text-align');
context.fillStyle = $(this).css('color');
context.fillText($(this).text(),
newCanvas.width / 2,
offset.top - baseOffset.top + $(this).height()
);
});
// add the legend
obj.children("table.jqplot-table-legend").each(function() {
var offset = $(this).offset();
var context = newCanvas.getContext("2d");
context.strokeStyle = $(this).css('border-top-color');
context.strokeRect(
offset.left - baseOffset.left,
offset.top - baseOffset.top,
$(this).width(),$(this).height()
);
context.fillStyle = $(this).css('background-color');
context.fillRect(
offset.left - baseOffset.left,
offset.top - baseOffset.top,
$(this).width(),$(this).height()
);
});
// add the rectangles
obj.find("div.jqplot-table-legend-swatch").each(function() {
var offset = $(this).offset();
var context = newCanvas.getContext("2d");
context.fillStyle = $(this).css('background-color');
context.fillRect(
offset.left - baseOffset.left,
offset.top - baseOffset.top,
$(this).parent().width(),$(this).parent().height()
);
});
obj.find("td.jqplot-table-legend").each(function() {
var offset = $(this).offset();
var context = newCanvas.getContext("2d");
context.font = $(this).css('font-style') + " " + $(this).css('font-size') + " " + $(this).css('font-family');
context.fillStyle = $(this).css('color');
context.textAlign = $(this).css('text-align');
context.textBaseline = $(this).css('vertical-align');
context.fillText($(this).text(),
offset.left - baseOffset.left,
offset.top - baseOffset.top + $(this).height()/2 + parseInt($(this).css('padding-top').replace('px',''))
);
});
// convert the image to base64 format
return newCanvas.toDataURL("image/png");
}