jQuery插件jcrop+Fileapi完美实现图片上传+裁剪+预览的代码分享

keyijing

2019-04-21

网页端裁剪图片，不需要经过服务器。

这个是用 https://github.com/mailru/FileAPI 框架实现的。配合jcrop.

高级浏览器使用 canvas 裁剪，ie6 7 8使用 flash过度。

核心代码：

var el = $('input').get(0);
     
     seajs.use(['gallery/jcrop/0.9.12/jcrop.css','gallery/jcrop/0.9.12/jcrop.js'] ,function(){
     
    FileAPI.event.on(el, 'change', function (evt){
      var files = FileAPI.getFiles(evt); // Retrieve file list
 
      FileAPI.filterFiles(files, function (file, info){
        if( !/^image/.test(file.type)  ){
          alert('图片格式不正确');
          return false;
        }
        else if(file.size > 20 * FileAPI.MB){
          alert('图片必须小于20M');
           return false;
        }
        else{
          return true;
        }
        
      }, function (files, rejected){
        console.log(files);
         
        if( files.length ){
          var file = files[0];
           var img0 = FileAPI.Image(file);
           var img1 = FileAPI.Image(file);
           var ratio = 0;
          FileAPI.getInfo(file, function (err, info) {  //get image ratio
              if (!err) {
                if (info.width > info.height) {
                  ratio = info.width / 500;
                }
                else {
                  ratio = info.height / 500;
                }
              }
            });
 
            img0.resize(500, 500, 'max')   //place image and register jcrop
                .get(function(err, img) {
                  $('#img2').empty();
                  $('#img2').append($(img));
 
                  $('#img2').children().Jcrop({
                    aspectRatio: 1,
                    bgColor: 'rgba(0,0,0,0.4)',
                    onSelect: function(c) {
                      img1.matrix.sx = c.x * ratio;
                      img1.matrix.sy = c.y * ratio;
                      img1.matrix.sw = c.w * ratio;
                      img1.matrix.sh = c.h * ratio;
                      img1.matrix.dw = 500;
                      img1.matrix.dh = 500;
 
                      img1.get(function(err, img) {
                        // $('#img3').empty();
                        //   $('#img3').append($(img));
                        $('#img3').html($(img));
                      });
 
                    }
                  });
                });
                  $('#btn').on('click',function(){
                        FileAPI.upload({
//                          url: '/testUpFile/upFile',
                          // headers: { 'Content-Type': 'multipart/form-data' },
                          files: { images: img1 },
                          progress: function (evt){ /* ... */ },
                          complete: function (err, xhr){ /* ... */
                            //alert(xhr.responseText);
                            console.log(xhr);
                          }
                        });              
                  });
          }
        });
      });
  });

完整代码：

<!DOCTYPE html>
<html>
  <head>
    <title>TODO supply a title</title>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width">
    <script src="./jquery.min.js"></script>  
    <script src="./jcrop/jquery.Jcrop.min.js"></script>
    <link href="./jcrop/jquery.Jcrop.min.css" rel="stylesheet">
  </head>
  <style>
    
    .upload-btn {
  width: 130px;
  height: 25px;
  overflow: hidden;
  position: relative;
  border: 3px solid #06c;
  border-radius: 5px;
  background: #0cf;

}
  .upload-btn:hover {
    background: #09f;
  }
  .upload-btn__txt {
    z-index: 1;
    position: relative;
    color: #fff;
    font-size: 18px;
    font-family: "Helvetica Neue";
    line-height: 24px;
    text-align: center;
    text-shadow: 0 1px 1px #000;
  }
  .upload-btn input {
    top: -10px;
    right: -40px;
    z-index: 2;
    position: absolute;
    cursor: pointer;
    opacity: 0;
    filter: alpha(opacity=0);
    font-size: 50px;
  }
    
  </style>
 
  
  <body>
    <div>
    <!-- "js-fileapi-wrapper" -- required class -->
    <div class="js-fileapi-wrapper upload-btn" id="choose">
       
      <input name="files" type="file" multiple />
      <button id="btn">上传</button>
    </div>
    <div id="images">
 
      <p style="margin-top: 40px;"></p>
      
      <div id="img2" ></div>
      
      <div id="img3"></div>
    </div>

  </div>

  <script>window.FileAPI = { staticPath: './fileapi/' };</script>
  <script src="./fileapi/FileAPI.min.js"></script>
  <script>
 
    var el = $('input').get(0);
    
 
    FileAPI.event.on(el, 'change', function (evt){
      var files = FileAPI.getFiles(evt); // Retrieve file list

      FileAPI.filterFiles(files, function (file, info){
        if( !/^image/.test(file.type)  ){
          alert('图片格式不正确');
          return false;
        }
        else if(file.size > 20 * FileAPI.MB){
          alert('图片必须小于20M');
           return false;
        }
        else{
          return true;
        }
        
      }, function (files, rejected){
 
        
        if( files.length ){
          var file = files[0];
           var img0 = FileAPI.Image(file);
           var img1 = FileAPI.Image(file);
           var ratio = 0;
          FileAPI.getInfo(file, function (err, info) {  //get image ratio
              if (!err) {
                if (info.width > info.height) {
                  ratio = info.width / 500;
                }
                else {
                  ratio = info.height / 500;
                }
              }
            });

            img0.resize(500, 500, 'max')   //place image and register jcrop
                .get(function(err, img) {
                  $('#img2').empty();
                  $('#img2').append($(img));

                  $('#img2').children().Jcrop({
                    aspectRatio: 1,
                    bgColor: 'rgba(0,0,0,0.4)',
                    onSelect: function(c) {
                      img1.matrix.sx = c.x * ratio;
                      img1.matrix.sy = c.y * ratio;
                      img1.matrix.sw = c.w * ratio;
                      img1.matrix.sh = c.h * ratio;
                      img1.matrix.dw = 500;
                      img1.matrix.dh = 500;

                      img1.get(function(err, img) {
                        // $('#img3').empty();
                        //   $('#img3').append($(img));
                        $('#img3').html($(img));
                      });

                    }
                  });
                });
                  $('#btn').on('click',function(){
                        FileAPI.upload({
                        url: '/testUpFile/upFile',
 
                          files: { images: img1 },
                          progress: function (evt){ /* ... */ },
                          complete: function (err, xhr){ /* ... */
                            //alert(xhr.responseText);
 
                          }
                        });
                    
                  });

          }
        });
      });
  
  </script>
  </body>
</html>

以上所述就是本文的全部内容了，希望大家能够喜欢。

jcrop 传照片 var jquery