[游戏开发]二维码生成/保存/打印

qrcodejs2生成二维码

需引用qrcodejs2

 try {
          if (this.qrStyle && this.qrStyle.text) {
            if (this.qrCode) {
              this.qrCode.clear(); // 清除二维码
              this.qrCode.makeCode(this.qrStyle.text); // 生成另外一个二维码
            } else {
              this.qrCode = new QRCode(this.$refs.qrCodeBox, this.qrStyle);
            }
          } else {
            this.$message.error("二维码生成参数为空");
          }
        } catch (e) {
          console.log(e)
          this.$message.error(e)
        }

js 保存二维码图片

	    try {
          //找到需要转换的canvas
          var data = this.$refs.qrCodeBox.children[0].toDataURL().replace("image/png",
            "image/octet-stream;"); //获取二维码值，并修改响应头部。
          var filename = `${this.hint||this.qrContent}.png`; //保存的图片名称和格式，canvas默认使用的png格式。这个格式效果最好。
          var save_link = document.createElement('a');
          save_link.href = data;
          save_link.download = filename;
          save_link.click()
        } catch (e) {
          console.log(e)
          this.$message.error(e)
        }

js 居中打印二维码

利用隐藏的iframe进行window.print()可以防止当前页面布局混乱(特别是Vue项目)

		  var content = this.$refs.printBox.innerHTML;
          var iframe = document.createElement('iframe');
          var f = document.body.appendChild(iframe);
          iframe.id = "myIframe";
          iframe.setAttribute('style', "display:table;position:relative;width:0px;height:0px;top:-10px;left:-10px;");
          var w = f.contentWindow || f.contentDocument;
          var doc = f.contentDocument || f.contentWindow.document;
          doc.open();
          doc.write(content);
          var qrBox = doc.getElementById("qrCodeBox");
          var ptStyle = this.printStyle
          if (!ptStyle) {
            ptStyle =
              `display:table-cell;vertical-align:middle;position:absolute;top:50%;left:50%;margin-top:-${this.qrWidth/2};margin-left:-${this.qrHeight/2};`
          }
          qrBox.setAttribute('style', ptStyle)
          var div = doc.getElementById('hint')
          var isShowHint = this.isPrintHint && this.hint
          div.style.display = isShowHint ? 'inline' : 'none';
          doc.close();
          w.focus();
          w.print();
          document.body.removeChild(iframe)
          w.close();
        } catch (e) {
          console.log(e)
          this.$message.error(e)
        }

body内容

	<div ref="printBox" class="code-image">
      <div id="qrCodeBox" ref="qrCodeBox"></div>
      <div id="hint" class="print-info">{{hint}}</div>
    </div>