在使用DTD解析此XML文件時，為什么會出現錯誤“StartTag：Invalid element name”

Question

該文檔基本上具有“目錄”作為根標簽，其中“電影”的子標簽后跟一個或多個“演員”。 這些子標簽中的每一個還包含更多子標簽。 我應該根據給出的一些規則為此制作一個DTD，但它只是拒絕我在doucment開頭放的任何東西。 有幫助嗎？

這是XML代碼：

<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>

<!DOCTYPE catalog SYSTEM "catalog.dtd">

<catalog>
    <movie movieID="m0100" genre="drama">
    <title>Monster&apos;s Ball</title>
<year>2001</year> 
<length>111 minutes</length>
<topBilledActors actorIDs="a0100 a0102" />
</movie>

<actor actorID="a0100" oscarWinner="yes">
    <name>Halle Berry</name>
<date>August 14, 1966</date>
<birthplace>Cleveland, Ohio</birthplace>
<role character="Leticia Musgrove" movie="m0100" />
<role character="Storm" movie="m0101" />
</actor>

<actor actorID="a0102" oscarWinner="yes">
    <name>Billy Bob Thornton</name>
<role character="Hank Grotowski" movie="m0100" />
</actor>

<movie movieID="m0101" genre="fantasy">
    <title>X-Men</title>
<year>2000</year>
<length>104 minutes</length>
<topBilledActors actorIDs="a0100 a0103" />
</movie>

<actor actorID="a0103" oscarWinner="no">
    <name>Ian McKellen</name>
<role character="Magneto" movie="m0101" />
<role character="Gandolf" movie="m0105" />
<role character="Gandolf" movie="m0107" />
</actor>

<movie movieID="m0105" genre="action" earningsRank="17">
    <name>Lord of the Rings: The Fellowship of the Ring</name>
<date>2001</date>
<length>178 minutes</length>
<topBilledActors actorIDs="a0103" />
</movie>

<movie movieID="m0107" genre="action" earningsRank="8">
    <name>Lord of the Rings: The Return of the King</name>
<date>2003</date>
<length>201 minutes</length>
<topBilledActors actorIDs="a0103" />
</movie>

<actor actorID="a0101" oscarWinner="yes">
<name>Tom Hanks</name>
<date>July 9, 1956</date>
<birthplace>Concord, California</birthplace>
<role character="Captain John H. Miller" movie="m0102" />
<role character="Forrest Gump" movie="m0103" />
<role character="Andrew Beckett" movie="m0104" />
</actor>

<movie movieID="m0102" genre="action" earningsRank="50">
    <name>Saving Private Ryan</name>
<date>1998</date>
<length>170 minutes</length>
<topBilledActors actorIDs="a0101 a0104" />
</movie>

<actor actorID="a0104" oscarWinner="yes">
    <name>Matt Damon</name>
<date>October 8, 1970</date>
<birthplace>Cambridge, Massachusetts</birthplace>
<role character="Private James Francis Ryan" movie="m0102" />
</actor>

<movie movieID="m0103" genre="comedy" earningsRank="14">
    <name>Forrest Gump</name>
<date>1994</date>
<length>142 minutes</length>
<topBilledActors actorIDs="a0101 a0105 a0106" />
</movie>

<actor actorID="a0105" oscarWinner="yes">
    <name>Sally Field</name>
<birthplace>Pasadena, California</birthplace>
<role character="Mrs. Gump" movie="m0103" />
</actor>

<actor actorID="a0106">
    <name>Gary Sinise</name>
<role character="Lt. Dan Taylor" movie="m0103" />
<role character="Ken Mattingly" movie="m0106" />
</actor>

<movie movieID="m0104" genre="drama">
    <name>Philadelphia</name>
<date>1993</date>
<length>125 minutes</length>
<topBilledActors actorIDs="a0101 a0107" />
</movie>

<movie movieID="m0106" genre="drama">
    <name>Apollo 13</name>
<date>1995</date>
<length>140 minutes</length>
<topBilledActors actorIDs="a0101 a0106" />
</movie>

<actor actorID="a0107" oscarWinner="yes">
    <name>Denzel Washington</name>
<role character="Joe Miller" movie="m0104" />
</actor>

</catalog>

這是DTD文件：

<!ELEMENT catalog (movie, actor+)*>

<!ELEMENT movie (title, year, length, topBilledActors)>
<!ATTLIST movie movieID ID #REQUIRED>
<!ATTLIST movie genre (fantasy |  action | drama | comedy) #REQUIRED>
<!ATTLIST movie earningsRank CDATA #IMPLIED>

<!ELEMENT title (#PCDATA)>
<!ELEMENT year (#PCDATA)>
<!ELEMENT length (#PCDATA)>
<!ELEMENT topBilledActors EMPTY>
<!ATTLIST topBilledActors ActorIDs IDREFS>

<!ELEMENT actor (name, date*, birthplace*, role+)>
<!ATTLIST actor actorID ID #REQUIRED>
<!ATTLIST actor oscarWinner (yes|no) "no">

<!ELEMENT name (#PCDATA)>
<!ELEMENT date (#PCDATA)>
<!ELEMENT birthplace (#PCDATA)>
<!ELEMENT role EMPTY>
<!ATTLIST role character CDATA>
<!ATTLIST role movie IDREF>

編輯：我正在使用XML驗證器驗證這一點， 網址為http://www.w3schools.com/xml/xml_validator.asp

我的Web瀏覽器（IE）不顯示該文件並給出錯誤：

Required white space was missing. Error processing resource 'file:///C:/Documents and        Settings/Administrator/Desktop/...

 <!ATTLIST topBilledActors ActorIDs IDREFS>

Answer 1

我認為您需要指定屬性是否為#REQUIRED或#IMPLIED或#FIXED“Default_Value”以使您的DTD有效。 你還應該有<!DOCTYPE 。