假設您要從資料庫中查詢出一些字串，然後填寫到表單的下拉選單中。
例如一個示意的Java程式如下：
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| package onlyfun.caterpillar;
?
publicclass Option {
public String[] getOptions() {
returnnew String[] {"良葛格", "毛美眉", "米小狗"};
}
} |
傳回的字串陣列，您要填寫到下拉選單中，當然，首先我們要在dwr.xml中開發這個物件…
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| <?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 1.0//EN""http://www.getahead.ltd.uk/dwr/dwr10.dtd">
<dwr>
<allow>
<create creator="new" javascript="OPT">
<param name="class" value="onlyfun.caterpillar.Option"/>
</create>
</allow>
</dwr>
|
這是我們的網頁…
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| <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=BIG5">
<script src="option.js" type="text/javascript"></script>
<script src="dwr/interface/OPT.js" type="text/javascript"></script>
<script src="dwr/engine.js" type="text/javascript"></script>
<script src="dwr/util.js" type="text/javascript"></script>
?
</head>
?
<body>
選項: <select id="opts"></select>
</body>
</html>
|
傳回的字串陣列會填入opts這個select中，我們的option.js如下…
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| window.onload = function() {
OPT.getOptions(populate);
};
?
function populate(list){
DWRUtil.removeAllOptions("opts");
DWRUtil.addOptions("opts", list);
} |
夠簡單了…不需要解釋了…
看一下結果…?
好啦！我知道有人在說了，這個程式有夠無聊…
改一下！就是個不錯的範例了，例如連動方塊，唔！在Ajax in action中叫啥？Dynamic double combo？…
假設一個會去從資料庫中查詢資料的Java程式示意如下：
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| package onlyfun.caterpillar;
?
import java.util.Map;
import java.util.TreeMap;
?
publicclass Bike {
??private Map<String, String[]> bikes;
??
??public Bike() {
????bikes = new TreeMap<String, String[]>();
????bikes.put("2000", new String[] {"2000 T1", "2000 T2", "2000 T3"});
????bikes.put("2001", new String[] {"2001 A1", "2001 A2"});
????bikes.put("2002", new String[] {"2002 BW1", "2002 BW2", "2002 BW"});
????bikes.put("2003", new String[] {"2003 S320"});
????bikes.put("2004", new String[] {"2004 TA1", "2004 TA2", "2004 TA3"});
??}
??
??public String[] getYears() {
????String[] keys = new String[bikes.size()];
????int i = 0;
????for(String key : bikes.keySet()) {
??????keys[i++] = key;
????}
????return keys;
??}
??
??public String[] getBikes(String year) {
????return bikes.get(year);
??}
} |
getYears()跟getBkies()分別表示產品的年份跟型號，這邊用Map模擬，實際上資料是來自資料庫的查詢。
一樣的，在dwr.xml中設定：
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| <?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 1.0//EN""http://www.getahead.ltd.uk/dwr/dwr10.dtd">
<dwr>
<allow>
<create creator="new" javascript="Bike" scope="application">
<param name="class" value="onlyfun.caterpillar.Bike"/>
</create>
</allow>
</dwr>
|
我們會有個腳踏車年份與型號查詢頁面：
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| <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=BIG5">
<title>Insert title here</title>
<script type='text/javascript' src='dwr/interface/Bike.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>
<script type='text/javascript' src='bike.js'></script>
</head>
<body onload="refreshYearList();">
??年份：<select id="years" onchange="refreshBikeList();"></select><br/><br/>
??型號：<select id="bikes"></select><br/>
</body>
</html>
|
注意，在選完第一個年份後，會觸發onchange事件，接著第二個下拉選單會自動填上對應年份的型號，而不是按鈕按下，再去取得第二個下拉選單，然後refresh...blah...blah...
bike.js如下…
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| function refreshYearList() {
Bike.getYears(populateYearList);
}
?
function populateYearList(list){
DWRUtil.removeAllOptions("years");
DWRUtil.addOptions("years", list);
refreshBikeList();
}
?
function refreshBikeList() {
var year = $("years").value;
Bike.getBikes(year, populateBikeList);
}
?
function populateBikeList(list){
DWRUtil.removeAllOptions("bikes");
DWRUtil.addOptions("bikes", list);
} |
一樣很簡單…
看個無聊的畫面…XD
Trackback: http://tb.blog.csdn.net/TrackBack.aspx?PostId=1239538
posted on 2007-03-05 11:48
壞男孩 閱讀(1061)
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java命令學習