js连接打印机打印图片(利用JS实现打印图片的新方式)

Introduction

Printing images has always been a tedious task, especially if the image is large or needs to be printed multiple times. But with the advancement of technology, a new way of printing images has emerged, called connecting and printing images using JavaScript. This new approach has made printing images easy and efficient for web developers. In this article, we will explore how to connect a printer to your web application and print an image using JavaScript.

Step 1: Installing the Printer Module

The first step to print an image using JavaScript is to install the printer module. There are many printer modules available, such as QZ Tray and JSPrintManager. In this example, we will be using the QZ Tray module. You can download the latest version of the QZ Tray module from their official website.

Step 2: Setting Up the Printer Connection

Once the printer module is installed, the next step is to set up the printer connection. To do this, we need to create a connection between the web application and the printer. This can be achieved by calling the `startConnection()` method of the printer module. It is important to note that the printer module needs to be running in the background while the web application is in use.

Step 3: Printing the Image

Now that we have established a connection between the web application and the printer, we can proceed to print the image. To print an image using the printer module, you need to first create a new print job. This can be achieved by calling the `getPrinter()` method of the printer module, followed by the `appendImage()` method to add the image to the print job. Finally, call the `print()` method to send the print job to the printer.

Example Code

Let us take a look at the code to print an image using JavaScript:

```

// Step 1: Install the printer module

// Step 2: Set up the printer connection

const qz = window.qz;

qz.security.setCertificatePromise(setCertificate);

qz.security.setSignaturePromise(setSignature);

qz.websocket.connect().then(function() {

console.log("Connected to QZ Tray!");

// Step 3: Print the Image

const config = qz.configs.create("PrinterName");

const data = document.getElementById("image").src;

const printData = [

{ type: "raw", format: "image/png", data: data }

];

qz.print(config, printData).catch(function(err) {

console.error(err);

});

});

function setCertificate(resolve, reject) {

// implement setCertificate logic here

}

function setSignature(toSign, callback) {

// implement setSignature logic here

}

```

Conclusion

Connecting and printing images using JavaScript is a new way of printing images that has made the printing process easy and efficient for web developers. With the help of the printer modules available, setting up and printing an image is a breeze. We hope that this article has helped you understand how to connect a printer to your web application and print an image using JavaScript.