我正在尝试将Admin Html网格导出为CSV.我有两个方法getCsv()和getCsvFile()用于将结果网格导出为CSV文件.请问有谁能告诉我这两个功能有什么区别？

方法-1

$fileName = "filename.csv";
$content    = $this->getLayout()->createBlock('custom_modelue/adminhtML_report_grid')
            ->getCsv();
$this->_PReparedownloadResponse($fileName,$content);

方法-2

$fileName = "filename.csv";
$content    = $this->getLayout()->createBlock('custom_modelue/adminhtml_report_grid')
            ->getCsvFile();
$this->_prepareDownloadResponse($fileName,$content);

当我使用方法-1时,滤镜未应用于导出CSV结果.但在方法-2中,过滤器适用于结果集.

get CsvFile() is 

     Retrieve a file container array by grid data as CSV

     Return array wITh keys tyPE and value

     return array

and getCsv() is 
    Retrieve Grid data as CSV
    and return string