我试图在 php 5.2 中使用 strlen() 找出字符串的确切长度。字符串 ($data) 包含 ' ' 和 ' '.
echo strlen($data);
代码:
// fetch table header
$header = '';
while ($fieldData = $result->fetch_field()) {
$header .= $fieldData->name . "\t";
}
// fetch data each row, store on tabular row data
while ($row = $result->fetch_assoc()) {
$line = '';
foreach($row as $value){
if(!isset($value) || $value == ""){
$value = "\t";
}else{
// important to escape any quotes to preserve them in the data.
$value = str_replace('"', '""', $value);
// needed to encapsulate data in quotes because some data might be multi line.
// the good news is that numbers remain numbers in Excel even though quoted.
$value = '"' . $value . '"' . "\t";
}
$line .= $value;
}
$data .= trim($line)."\n";
}
// this line is needed because returns embedded in the data have "\r"
// and this looks like a "box character" in Excel
$data = str_replace("\r", "", $data);
// Nice to let someone know that the search came up empty.
// Otherwise only the column name headers will be output to Excel.
if ($data == "") {
$data = "\nno matching records found\n";
}
// create table header showing to download a xls (excel) file
header("Content-type: application/octet-stream");
header("Content-Disposition: attachment; filename=$export_filename");
header("Cache-Control: public");
header("Content-length: " . strlen($data); // tells file size
header("Pragma: no-cache");
header("Expires: 0");
// output data
echo $header."\n".$data;
这不会返回准确的长度(它小于实际长度)。请指教。
您告诉用户代理期待 strlen($data),然后实际发送 $header。” “.$data!在代码末尾尝试类似的内容...
$output=$header."\n".$data;
// create table header showing to download a xls (excel) file
header("Content-type: application/octet-stream");
header("Content-Disposition: attachment; filename=$export_filename");
header("Cache-Control: public");
header("Content-length: " . strlen($output); // tells file size
header("Pragma: no-cache");
header("Expires: 0");
// output data
echo $output;
内容长度标头不包括标头长度加上响应正文。
Content-Length: 响应正文的长度(以八位字节为单位(8 位字节))
仅供参考,因为“答案”中使用的变量是标题+数据。不要被误导。
在获取字符串长度之前,如果
'\t'
确实有错误(我还没有检查过),请使用'\n'
或类似的其他函数从$data
中删除str_replace
和strlen()
符号。
您回显了
$header
和 $data
,但您仅将 Content-Length
设置为 $data
的大小。
如果
$header
包含其他 HTTP 标头,则应使用 $header
输出 header()
。否则,您应该将 Content-Length
设置为 strlen($header."\n".$data)
。