Javascript Dropzone筛选文件

我已经尝试了将近一周的时间来实现这一点，我一直在尝试在dropzone中使用

accept:

选项来归档一些文件，我想允许最多2个文件的类型为

“image/png”和“image/jpeg”

，当我在dropzone中有2个这样的类型时，提醒用户她或他达到了最大值，同时允许用户上传歌曲

代码在某种程度上起作用，但如果我添加到具有音频mime类型的文件中，那么在添加图像后，它会显示图像警告，但实际上尚未达到该限制

accept: function(file, done){

  // Variables
  var _this = this.getAcceptedFiles(),
      ext = file.name.split('.')
      jpeg = 'image/jpeg',
      png = 'image/png';


  console.log(this.getAcceptedFiles())
  console.log('added')


  // Adding extension to screen for user to see
  $(file.previewElement.childNodes[1]).children().text(ext[ext.length - 1])

  // function in charge of showing and hiding the info box
  // and in charge of displying scrollbar
  box_show();

  // check if file already exist in list
  if (check_the_same(_this, file)){

    done('File ' + file.name + ' already in exist.');

  }else{

    // if file is a image check if we have more than two in list
    if (file.type == jpeg || png){
      if (more_than_2(_this, file)){

        done('Remember just up to 2 images.');
      }else{

        done();
      }

    }else{
      done()
    }
  }
}

重复文件的功能检查：

function check_the_same(_this, file){

  // loop to check if file already exists in added file list
  for(var i = 0; _this.length > i; i++ ){

    // if file name is in already created list show alert    
    console.log($('div#list-container #h').children().length)
    if (file.name == _this[i].name){

      return true
    }

  }

}

function more_than_2(_this, file){

  var num_check = 0;

  for (var i = 0; _this.length > i; i++){
  console.log(_this);

    if (file.type == 'image/jpeg' || 'image/png'){
      console.log(file.type == 'image/jpeg');

      num_check += 1;

      if (num_check >= 2){
        console.log('true')

        return true
      }

    }
  }
}

检查图像数量的函数：

function check_the_same(_this, file){

  // loop to check if file already exists in added file list
  for(var i = 0; _this.length > i; i++ ){

    // if file name is in already created list show alert    
    console.log($('div#list-container #h').children().length)
    if (file.name == _this[i].name){

      return true
    }

  }

}

function more_than_2(_this, file){

  var num_check = 0;

  for (var i = 0; _this.length > i; i++){
  console.log(_this);

    if (file.type == 'image/jpeg' || 'image/png'){
      console.log(file.type == 'image/jpeg');

      num_check += 1;

      if (num_check >= 2){
        console.log('true')

        return true
      }

    }
  }
}

---

嗯，你一直在做什么

file.type == 'image/jpeg' || 'image/png'

在您的循环中，如果您总共有2个或更多文件，并且您正试图上载图像，那么它将失败

正确答案应该是：

_this[i].type == 'image/jpeg' || 'image/png'