本文主要解決在 ie6 下，jquery 無法設置 select 選中的問題。我們先看個例子：
<!DOCTYPE HTML> <html lang="en-US"> <head> <meta charset="UTF-8"/> <title>demo</title> </head> <body> <select name="gameZone" id="gameZone"> <option value="0">請選擇游戲大區</option> <option value="1">游戲一區</option> <option value="2">游戲二區</option> </select> </body> </html> <script type="text/javascript" src="/js/jquery.min.js"></script> <script type="text/javascript"> $(function(){ $.each($('#gameZone > option'),function(){ if($(this).val() == '1'){ $(this).attr('selected','selected'); } }); }); </script>
以上代碼在所有瀏覽器中都沒有問題，打開頁面 select 會選中第二個選項。那么當 select 里的內容是動態添加的，又會是怎樣的情況呢？
<!DOCTYPE HTML> <html lang="en-US"> <head> <meta charset="UTF-8"/> <title>demo</title> </head> <body> <select name="gameZone" id="gameZone"> <option value="0">請選擇游戲大區</option> </select> </body> </html> <script type="text/javascript" src="/js/jquery.min.js"></script> <script type="text/javascript"> var servers ='[{"gm_id":33,"groups":[{"index":"1","name":"\u4f20\u4e16\u51b7\u6708","id":"game1"}],"id":"dx1","name":"\u7535\u4fe1\u4e00\u533a"},{"gm_id":39,"groups":[{"index":"3","name":"\u4ed9\u5251\u604b\u5f71","id":"game3"}],"id":"dx4","name":"\u7535\u4fe1\u4e8c\/\u4e09\/\u56db\/\u4e94\/\u516d\u533a"},{"gm_id":49,"groups":[{"index":"1","name":"\u7b11\u50b2\u5343\u53e4","id":"game1"}],"id":"dx7","name":"\u7535\u4fe1\u4e03\u533a\/\u516b\u533a\/\u4e5d\u533a"},{"gm_id":62,"groups":[{"index":"1","name":"\u98ce\u5f71\u76db\u5bb4","id":"game1"}],"id":"dx10","name":"\u7535\u4fe1\u5341\u533a"},{"gm_id":68,"groups":[{"index":"1","name":"\u70c8\u65e5\u661f\u5b87","id":"game1"},{"index":"3","name":"\u5929\u67a2\u661f\u8fb0","id":"game3"},{"index":"5","name":"\u7eb5\u5730","id":"game5"},{"index":"6","name":"\u91d1\u83b2","id":"game6"}],"id":"dx11","name":"\u7535\u4fe1\u5341\u4e00\u533a"}]'; function showZone(){ var serversLists = eval(servers); var serversHtml = '<option value="0">請選擇游戲大區</option>'; for(var i = 0; i < serversLists.length; i++){ serversHtml += '<option value="' + serversLists[i].id + '">' + serversLists[i].name + '</option>'; } return serversHtml; }; $(function(){ $('#gameZone').html(showZone()); $.each($('#gameZone > option'),function(){ if($(this).val() == 'dx1'){ $(this).attr('selected','selected'); } }); }); </script>
我們可以看到在 chrome，firefox，ie8，ie7 這些瀏覽器都沒有問題，但是在蛋疼的 ie6 瀏覽器中會 js 報錯（無法設置 selected 屬性，未指明的錯誤）。
解決方法有兩種：setTimeout 和 try/catch
第一種：setTimeout（推薦）
<!DOCTYPE HTML> <html lang="en-US"> <head> <meta charset="UTF-8"/> <title>demo</title> </head> <body> <select name="gameZone" id="gameZone"> <option value="0">請選擇游戲大區</option> </select> </body> </html> <script type="text/javascript" src="/js/jquery.min.js"></script> <script type="text/javascript"> var servers ='[{"gm_id":33,"groups":[{"index":"1","name":"\u4f20\u4e16\u51b7\u6708","id":"game1"}],"id":"dx1","name":"\u7535\u4fe1\u4e00\u533a"},{"gm_id":39,"groups":[{"index":"3","name":"\u4ed9\u5251\u604b\u5f71","id":"game3"}],"id":"dx4","name":"\u7535\u4fe1\u4e8c\/\u4e09\/\u56db\/\u4e94\/\u516d\u533a"},{"gm_id":49,"groups":[{"index":"1","name":"\u7b11\u50b2\u5343\u53e4","id":"game1"}],"id":"dx7","name":"\u7535\u4fe1\u4e03\u533a\/\u516b\u533a\/\u4e5d\u533a"},{"gm_id":62,"groups":[{"index":"1","name":"\u98ce\u5f71\u76db\u5bb4","id":"game1"}],"id":"dx10","name":"\u7535\u4fe1\u5341\u533a"},{"gm_id":68,"groups":[{"index":"1","name":"\u70c8\u65e5\u661f\u5b87","id":"game1"},{"index":"3","name":"\u5929\u67a2\u661f\u8fb0","id":"game3"},{"index":"5","name":"\u7eb5\u5730","id":"game5"},{"index":"6","name":"\u91d1\u83b2","id":"game6"}],"id":"dx11","name":"\u7535\u4fe1\u5341\u4e00\u533a"}]'; function showZone(){ var serversLists = eval(servers); var serversHtml = '<option value="0">請選擇游戲大區</option>'; for(var i = 0; i < serversLists.length; i++){ serversHtml += '<option value="' + serversLists[i].id + '">' + serversLists[i].name + '</option>'; } return serversHtml; }; $(function(){ $('#gameZone').html(showZone()); setTimeout(function(){ $.each($('#gameZone > option'),function(){ if($(this).val() == 'dx1'){ $(this).attr('selected','selected'); } }); },1); }); </script>
第二種：try/catch
<!DOCTYPE HTML> <html lang="en-US"> <head> <meta charset="UTF-8"/> <title>demo</title> </head> <body> <select name="gameZone" id="gameZone"> <option value="0">請選擇游戲大區</option> </select> </body> </html> <script type="text/javascript" src="/js/jquery.min.js"></script> <script type="text/javascript"> var servers ='[{"gm_id":33,"groups":[{"index":"1","name":"\u4f20\u4e16\u51b7\u6708","id":"game1"}],"id":"dx1","name":"\u7535\u4fe1\u4e00\u533a"},{"gm_id":39,"groups":[{"index":"3","name":"\u4ed9\u5251\u604b\u5f71","id":"game3"}],"id":"dx4","name":"\u7535\u4fe1\u4e8c\/\u4e09\/\u56db\/\u4e94\/\u516d\u533a"},{"gm_id":49,"groups":[{"index":"1","name":"\u7b11\u50b2\u5343\u53e4","id":"game1"}],"id":"dx7","name":"\u7535\u4fe1\u4e03\u533a\/\u516b\u533a\/\u4e5d\u533a"},{"gm_id":62,"groups":[{"index":"1","name":"\u98ce\u5f71\u76db\u5bb4","id":"game1"}],"id":"dx10","name":"\u7535\u4fe1\u5341\u533a"},{"gm_id":68,"groups":[{"index":"1","name":"\u70c8\u65e5\u661f\u5b87","id":"game1"},{"index":"3","name":"\u5929\u67a2\u661f\u8fb0","id":"game3"},{"index":"5","name":"\u7eb5\u5730","id":"game5"},{"index":"6","name":"\u91d1\u83b2","id":"game6"}],"id":"dx11","name":"\u7535\u4fe1\u5341\u4e00\u533a"}]'; function showZone(){ var serversLists = eval(servers); var serversHtml = '<option value="0">請選擇游戲大區</option>'; for(var i = 0; i < serversLists.length; i++){ serversHtml += '<option value="' + serversLists[i].id + '">' + serversLists[i].name + '</option>'; } return serversHtml; }; $(function(){ $('#gameZone').html(showZone()); try{ $.each($('#gameZone > option'),function(){ if($(this).val() == 'dx1'){ $(this).attr('selected','selected'); } }); }catch(e){} }); </script>