Javascript中自动切换焦点实现代码_基础知识



代码如下:






window.onload = function() {
var EventUtil = {
addhandler:function(element,type,handler) {
if(element.addEventListenter) {
element.addEventListenter(type,handler,false);
} else if (element.attachEvent) {
element.attachEvent("on"+type,handler);
} else {
element["on"+type] = handler;
}
},

getEvent:function(event) {
return event?event:window.event;
},

getTarget:function() {
return event.target || event.srcElement;
},

preventDefault:function() {
if(event.preventDefault) {
event.preventDefault();
} else {
event.returnValue = false;
}
},

stopPropagation:function() {
if(event.stopPropagation) {
event.stopPropagation();
} else {
event.cancelBuddle = true;
}
},

removehandler:function(element,type,handler) {
if(element.removeEventListenter) {
element.addEventListenter(type,handler,false);
} else if (element.detachEvent) {
element.detachEvent("on"+type,handler);
} else {
element["on"+type] = null;
}
},

getCharCode: function(event) {
if(typeof event.charCode == "number") {
return event.charCode;
} else {
return event.keyCode;
}
},

getClipboardText: function(event) {
var clipboardData = event.clipboardData || window.clipboardData;
return clipboardData.getData("text");
},

setClipboardText: function(event,value) {
if(event.clipboardData) {
return event.clipboardData.setData("text/plain",value);
} else if(window.clipboardData){
return window.clipboardData.setData("text",value);
}
}

}

var textarea = document.forms[0].elements["text"];
var button = document.getElementById("button");

(function() {
function tabForward(event) {
event = EventUtil.getEvent(event);
var target = EventUtil.getTarget(event);

if(target.value.length == target.maxLength) {
var form = target.parentElement;

for(var i=0,len = form.elements.length;iif(form.elements[i] == target) {
form.elements[i+1].focus();
return ;
}
}
}

}

var textTel1 = document.getElementById("txtTel1");
var textTel2 = document.getElementById("txtTel2");
var textTel3 = document.getElementById("txtTel3");

EventUtil.addhandler(textTel1,"keyup",tabForward);
EventUtil.addhandler(textTel2,"keyup",tabForward);
EventUtil.addhandler(textTel3,"keyup",tabForward);

})();
}