function( status ) {
                var len = this._queue.length,
                    i, file;
    
                status = status || STATUS.QUEUED;
    
                for ( i = 0; i < len; i++ ) {
                    file = this._queue[ i ];
    
                    if ( status === file.getStatus() ) {
                        return file;
                    }
                }
    
                return null;
            }
function( status ) {
                var len = this._queue.length,
                    i, file;
    
                status = status || STATUS.QUEUED;
    
                for ( i = 0; i < len; i++ ) {
                    file = this._queue[ i ];
    
                    if ( status === file.getStatus() ) {
                        return file;
                    }
                }
    
                return null;
            }
function ( status ) { var len = this . _queue . length , i , file ; status = status || STATUS . QUEUED ; for ( i = 0 ; i < len ; i ++ ) { file = this . _queue [ i ] ; if ( status === file . getStatus ( ) ) { return file ; } } return null ; }
从队列中取出一个指定状态的文件。
@grammar fetch( status ) => File
@method fetch
@param {String} status [文件状态值](#WebUploader:File:File.Status)
@return {File} [File](#WebUploader:File)
从队列中取出一个指定状态的文件。
Returns the first file in the queue that matches the status