Ajax总结

1，自己封装ajax对象，如下：

var Ajax = function(setting) {
	if (window.XMLHttpRequest)
		xhr = new XMLHttpRequest();
	else {
		xhr = new ActiveXObject("Microsoft.XMLHTTP");
	}
	xhr.onreadystatechange = function() {
		if (xhr.readyState == 4) {
			if (xhr.status == 200) {
				if (setting.success)
					setting.success(xhr.responseText);
				else
					console.log(xhr.responseText);
			} else {
				if (setting.error)
					setting.error(xhr.status);
				else {
					console.log('Error:' + xhr.status);
				}
			}
		}
	};


	var data = "";
	if (typeof setting.data === 'string') {
		data = setting.data;
		if (data.charAt(0) == '?')
			data = data.substring(1, data.length);
	} else if (typeof setting.data == 'object') {
		for (key in setting.data) {
			data += key + '=' + setting.data[key] + '&';
		}
		data = data.replace(/&$/, '');
	}


	var type = setting.type || 'GET';


	if (type == 'GET') {// GET方式提交
		xhr.open(type, setting.url + '?' + data, true);
		xhr.send();
	} else {// POST方式提交
		xhr.open(type, setting.url, true);
		xhr.setRequestHeader("Content-type",
				"application/x-www-form-urlencoded");
		xhr.send(data);
	}
};

使用：

Ajax({
	url : "url",
	type : 'POST',
	data : {
		key : value
	},
	success : function(msg) {
		alert(msg);
	},
	error : function(msg) {
		alert('error');
	}
});

2,使用jQuery库，如下：

$.ajax({
        url : "url",
	type : "post",
	data : {
		key : value
	},
	dataType : "json",
	success : function(msg) {
		alert(msg);
	},
	error : function(XMLHttpRequest, textStatus, errorThrown) {
		alert(textStatus);
	}
});