function openFileByUrl(url){
    console.log('url='+url); 
    this.showLoading();  
    var hearder = getHeader(url);
    console.log(hearder);
    wx.downloadFile({
        url: url,
        header: hearder ,         
        success: function (res) {         
            console.log(res);           
            var filePath = res.tempFilePath;
            console.log('filePath==='+filePath);           
            wx.openDocument({
            filePath: filePath,
            success: function (res) {
                console.log('打开文档成功')
            },
            fail:function(err){ 
                alert(err.errMsg);
            }
            })
        },
        complete:function(){
          console.log('compleate');
          wx.hideLoading();
        }
    })
}

安卓手机下载附件（不管是doc，还是pdf）后缀名变成了.htm。然后打开就报：fail file type not supported 2003，ios下正常。

请问什么问题？感谢