Articles in this section
Category / Section

How to export multiple gauges in single image file in .NET WebForms Digital Gauge ?

4 mins read


The requirement here is to export multiple gauges into a single page in ASP.NET Web Forms Digital Gauge.


Usually, when multiple gauges are rendered together in a single page, you can not directly export all the gauges altogether as a single image file. It can be performed by exporting each gauge as a separate image file by using export action. To export multiple gauges together into a single image file, retrieve all the gauge elements and add those elements into a new canvas element and then export that canvas element by using the following method.


function buttonclickevent() {
    //To get all the canvas elements
    var canvas1 = $('canvas');
    var b_canvas = new Array();
    for (var l = 0; canvas1[l] != null; l++) {
        b_canvas[l] = canvas1[l];
    //To get only selected canvas elements instead of all canvas element.
    //b_canvas[0] = canvas1[0];
    //b_canvas[1] = canvas1[1];
    //create a temporary canvas to store the combined canvas element.
    var buffer = document.createElement("canvas");
    buffer.width = 0;
    buffer.height = 0;
    //set the total  width and height for Resultant canvas
    for (var i = 0; i < b_canvas.length; i++) {
        buffer.width += b_canvas[i].width;
        buffer.height += b_canvas[i].height;
    var yPosition = 0;
    var buffer_context = buffer.getContext("2d");
    //Draw the canvas
    for (var j = 0; j < b_canvas.length; j++) {
        buffer_context.drawImage(b_canvas[j], 0, yPosition, b_canvas[j].width, b_canvas[j].height);
        yPosition += b_canvas[j].height;
    //method to export all gauges in single file
    exportImage(buffer, "myImage", "png");
function exportImage(buffer, fileName, fileType) {
    var lnk = document.createElement('a'), e; = fileName + "." + fileType;
    lnk.href = buffer.toDataURL("image/" + fileType).replace("image/" + fileType, "image/octet-stream");
    if (document.createEvent) {
        e = document.createEvent("MouseEvents");
        e.initMouseEvent("click", true, true, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
    } else if (lnk.fireEvent) {

Executing the above example, exports the multiple Circular Gauges altogether as a single image file, while clicking on the export gauge button.

Multiple Circular gauges exported as a single image in ASP.NET Web Forms Digital Gauge.

Figure 1: Multiple Circular gauges exported as a single image

Sample link:



I hope you enjoyed learning about how to export multiple gauges in single image file.

You can refer to our ASP.NET Web Forms Digital Gauge’s feature tour page to know about its other groundbreaking feature representations. You can also explore our ASP.NET Web Forms Digital Gauge example to understand how to present and manipulate data. 

For current customers, you can check out our ASP.NET Web Forms components from the License and Downloads page. If you are new to Syncfusion, you can try our 30-day free trial to check out our ASP.NET Web Forms Digital Gauge and other ASP.NET Web Forms components.

If you have any queries or require clarifications, please let us know in comments below. You can also contact us through our support forums, Direct-Trac, or feedback portal. We are always happy to assist you!



Did you find this information helpful?
Help us improve this page
Please provide feedback or comments
Comments (0)
Please sign in to leave a comment