我正在尝试将 an 的内容类型与HttpPostedFileBase
一系列可接受的类型进行比较,并且遇到了一些真正奇怪的行为。
array.Contains()
找不到字符串,但是如果我遍历集合并将每个条目与字符串进行比较,它就会得到匹配。
这是我的代码:
string[] acceptable = new string[]{
"text/comma-separated-values",
"text/csv",
"text/anytext",
"application/csv",
"application/excel",
"application/octet-stream",
"application/vnd.ms-excel",
"application/vnd.msexcel"
};
string type = model.file.ContentType.ToLower().Trim();
string err = "acceptable.Contains(type) = " +
(acceptable.Contains(type) ? "true" : "false");
err += "<br/><br/>";
foreach (string s in acceptable)
{
if (s == type)
err += "but " + type + " is definitely in the string array!";
}
上面的代码输出如下
acceptable.Contains(type) = false
but application/octet-stream is definitely present in the string array!
如果我将打印的值复制并粘贴file.ContentType
到字符串变量中并运行比较,它工作正常。仅在直接从 读取值时才会失败,顺便说一下HttpPostedFileBase.ContentType
,这是类型System.String
。