JS打印

我们通过前端上传到数据库的pdf或者word文档，当我们在线观看时，希望使用调用本地的打印进行实时打印；当然可能会涉及到安全问题，有需要的小伙伴，可以自行查阅。

// 打印类属性、方法定义
/* eslint-disable */



// ActiveXObject 是window自带的打印类，也就是所谓的控件
function isIE () {
  if (!!window.ActiveXObject || 'ActiveXObject' in window) {
    return true
  } else {
    return false
  }
}


const Print = function (dom, options) {
  if (!(this instanceof Print)) return new Print(dom, options)


  this.options = this.extend({
    'noPrint': '.no-print'
  }, options)


  if ((typeof dom) === 'string') {
    this.dom = document.querySelector(dom)
  } else {
    this.dom = dom
  }


  this.init()
}
Print.prototype = {
  init: function () {
    var content = this.getStyle() + this.getHtml()
    this.writeIframe(content)
  },
  extend: function (obj, obj2) {
    for (var k in obj2) {
      obj[k] = obj2[k]
    }
    return obj
  },


  getStyle: function () {
    var str = '',
      styles = document.querySelectorAll('style,link')
    for (var i = 0; i < styles.length; i++) {
      str += styles[i].outerHTML
    }
    str += '<style>' + (this.options.noPrint ? this.options.noPrint : '.no-print') + '{display:none;}</style>'


    return str
  },


  getHtml: function () {
    var inputs = document.querySelectorAll('input')
    var textareas = document.querySelectorAll('textarea')
    var selects = document.querySelectorAll('select')


    for (var k in inputs) {
      if (inputs[k].type == 'checkbox' || inputs[k].type == 'radio') {
        if (inputs[k].checked == true) {
          inputs[k].setAttribute('checked', 'checked')
        } else {
          inputs[k].removeAttribute('checked')
        }
      } else if (inputs[k].type == 'text') {
        inputs[k].setAttribute('value', inputs[k].value)
      }
    }


    for (var k2 in textareas) {
      if (textareas[k2].type == 'textarea') {
        textareas[k2].setAttribute('style', 'height: 320px;')
        textareas[k2].innerHTML = textareas[k2].value
      }
    }


    for (var k3 in selects) {
      if (selects[k3].type == 'select-one') {
        var child = selects[k3].children
        for (var i in child) {
          if (child[i].tagName == 'OPTION') {
            if (child[i].selected == true) {
              child[i].setAttribute('selected', 'selected')
            } else {
              child[i].removeAttribute('selected')
            }
          }
        }
      }
    }


    return this.dom.outerHTML
  },


  writeIframe: function (content) {


    if (isIE()) {
      // 通过Iframe读取
      let iframe = window.open('','_blank')
      iframe.document.clear()
      iframe.document.write(content + '<object id="printObj" name="printObj" style="dispaly:none" classid="clsid:8856F961-340A-11D0-A96B-00C04FD705A2" height=0 width=0></object><script languge="Javascript">printObj.ExecWB(7, 1)</script>')
    //   iframe.print() //打印
    //   iframe.document.execCommand('print')
        iframe.close()
    } else {
      var w, doc, iframe = document.createElement('iframe'),
        f = document.body.appendChild(iframe)
      iframe.id = 'myIframe'
      iframe.name = 'myIframe'


      iframe.setAttribute('style', 'position:absolute;width:0;height:0;top:-10px;left:-10px;')
      console.log(iframe)
      w = f.contentWindow || f.contentDocument
      doc = f.contentDocument || f.contentWindow.document
      doc.open()
      setTimeout(() => {
          doc.write(content)
          doc.close()
          this.toPrint(w)
      }, 2000);
    }
  },


  toPrint: function (frameWindow) {
    try {
      setTimeout(function () {
        frameWindow.focus()
        try {
          if (!frameWindow.document.execCommand('print', false, null)) {
            frameWindow.print()
          }
        } catch (e) {
          frameWindow.print()
        }
        frameWindow.close()
      }, 100)
    } catch (err) {
      console.log('err', err)
    }
  }
}
const MyPlugin = {}
MyPlugin.install = function (Vue, options) {
    // 4. 添加实例方法
    Vue.prototype.$print = Print
}
export default MyPlugin