如何使用json在前后台进行数据传输实例介绍

上一篇博客写到用javascript生成多组文本，可以让数据的输入不受显示，现在我们需要把这些输入写入数据库，这里就用到json传入。

首先，我们来写一下后台如何生成要传输的数据
[html]

function generateDtb() { 
//写入 
var txtName = document.getElementById("txtName").value; 
//创建数组 
var dtb = new Array(); 
//通过循环把数据写入到数组并返回 
for (var i = 0; i < firstGroup.length; i++) { 
var row = new Object(); 
row.Name = txtName; 
row.fullMoney = firstGroup[i].value; 
row.discount = secondGroup[i].value; 
dtb.push(row); 
} 
return dtb; 
} 
function generateDtb() { 
//写入 
var txtName = document.getElementById("txtName").value; 
//创建数组 
var dtb = new Array(); 
//通过循环把数据写入到数组并返回 
for (var i = 0; i < firstGroup.length; i++) { 
var row = new Object(); 
row.Name = txtName; 
row.fullMoney = firstGroup[i].value; 
row.discount = secondGroup[i].value; 
dtb.push(row); 
} 
return dtb; 
}

把数组转换成json串传入到后台：
[html]

$(function () { 
//点击botton1 
$("#lbtnOK").click(function () { 
var url = "DiscountManger.aspx?ajax=1"; 
var dtb = generateDtb(); 
// var strName = document.getElementById("txtName").value; 
if (dtb == null) 
{ } 
else { 
//序列化对象 
var postdata = JSON.stringify(dtb); 
//异步请求 
$.post(url, { json: postdata }, function (json) { 
if (json) { 
jBox.tip("添加成功！", "提示"); 
location.reload(); 
} 
else { 
jBox.tip("添加失败！", "提示"); 
location.reload(); 
} 
}, "json") 
} 
}); 
}); 
$(function () { 
//点击botton1 
$("#lbtnOK").click(function () { 
var url = "DiscountManger.aspx?ajax=1"; 
var dtb = generateDtb(); 
// var strName = document.getElementById("txtName").value; 
if (dtb == null) 
{ } 
else { 
//序列化对象 
var postdata = JSON.stringify(dtb); 
//异步请求 
$.post(url, { json: postdata }, function (json) { 
if (json) { 
jBox.tip("添加成功！", "提示"); 
location.reload(); 
} 
else { 
jBox.tip("添加失败！", "提示"); 
location.reload(); 
} 
}, "json") 
} 
}); 
});

在后台的操作：
首先判断是否需要传输数据
[html]

if (!IsPostBack) 
{ 
//判断是否异步请求 
if (Request.QueryString["ajax"] == "1") 
{ 
ProcessRequest(); 
} 
if (!IsPostBack) 
{ 
//判断是否异步请求 
if (Request.QueryString["ajax"] == "1") 
{ 
ProcessRequest(); 
}

在这里进行对数据的处理：
[html]

/// <summary> 
/// 处理异步请求 
/// </summary> 
private void ProcessRequest() 
{ 
//存入要填写的策略 
ArrayList arrDiscount = new ArrayList(); 
Response.ContentType = "text/html"; 
string json = Request.Form["json"]; 
//反序列化DataTable 
if (json == null) 
{ 
return; 
} 
else 
{ 
DataTable newdtb = Json2Dtb(json); 
for (int i = 0; i < newdtb.Rows.Count; i++) 
{ 
Entity.StrategyDiscount enStrategyDiscount = new Entity.StrategyDiscount(); 
//打折方案名 
enStrategyDiscount.name = newdtb.Rows[i]["Name"].ToString(); 
//商店ID 
enStrategyDiscount.shopId = long.Parse(LoginInfo.ShopID); 
enStrategyDiscount.fullMoney = Convert.ToDecimal(newdtb.Rows[i]["fullMoney"].ToString()); 
enStrategyDiscount.discount = Convert.ToDecimal(newdtb.Rows[i]["discount"].ToString()); 
//写入数据到数组 
arrDiscount.Add(enStrategyDiscount); 
} 
//写入数据到数据库 
IStrategyBLL strategy = new StrategyBLL(); 
if (strategy.AddStrategyDiscount(arrDiscount)) 
{ 
Response.Write("true"); 
Response.End(); 
} 
else 
{ 
Response.Write("false"); 
Response.End(); 
} 
} 
/// <summary> 
/// 处理异步请求 
/// </summary> 
private void ProcessRequest() 
{ 
//存入要填写的策略 
ArrayList arrDiscount = new ArrayList(); 
Response.ContentType = "text/html"; 
string json = Request.Form["json"]; 
//反序列化DataTable 
if (json == null) 
{ 
return; 
} 
else 
{ 
DataTable newdtb = Json2Dtb(json); 
for (int i = 0; i < newdtb.Rows.Count; i++) 
{ 
Entity.StrategyDiscount enStrategyDiscount = new Entity.StrategyDiscount(); 
//打折方案名 
enStrategyDiscount.name = newdtb.Rows[i]["Name"].ToString(); 
//商店ID 
enStrategyDiscount.shopId = long.Parse(LoginInfo.ShopID); 
enStrategyDiscount.fullMoney = Convert.ToDecimal(newdtb.Rows[i]["fullMoney"].ToString()); 
enStrategyDiscount.discount = Convert.ToDecimal(newdtb.Rows[i]["discount"].ToString()); 
//写入数据到数组 
arrDiscount.Add(enStrategyDiscount); 
} 
//写入数据到数据库 
IStrategyBLL strategy = new StrategyBLL(); 
if (strategy.AddStrategyDiscount(arrDiscount)) 
{ 
Response.Write("true"); 
Response.End(); 
} 
else 
{ 
Response.Write("false"); 
Response.End(); 
} 
}

这里，我们需要把json转换成datatable
[html]

/// <summary> 
/// Json转DataTable 
/// </summary> 
/// <param name="json"></param> 
/// <returns></returns> 
private DataTable Json2Dtb(string json) 
{ 
JavaScriptSerializer jss = new JavaScriptSerializer(); 
ArrayList dic = jss.Deserialize<ArrayList>(json); 
DataTable dtb = new DataTable(); 
if (dic.Count > 0) 
{ 
foreach (Dictionary<string, object> drow in dic) 
{ 
if (dtb.Columns.Count == 0) 
{ 
foreach (string key in drow.Keys) 
{ 
dtb.Columns.Add(key, drow[key].GetType()); 
} 
} 
DataRow row = dtb.NewRow(); 
foreach (string key in drow.Keys) 
{ 
row[key] = drow[key]; 
} 
dtb.Rows.Add(row); 
} 
} 
return dtb; 
} 
/// <summary> 
/// Json转DataTable 
/// </summary> 
/// <param name="json"></param> 
/// <returns></returns> 
private DataTable Json2Dtb(string json) 
{ 
JavaScriptSerializer jss = new JavaScriptSerializer(); 
ArrayList dic = jss.Deserialize<ArrayList>(json); 
DataTable dtb = new DataTable(); 
if (dic.Count > 0) 
{ 
foreach (Dictionary<string, object> drow in dic) 
{ 
if (dtb.Columns.Count == 0) 
{ 
foreach (string key in drow.Keys) 
{ 
dtb.Columns.Add(key, drow[key].GetType()); 
} 
} 
DataRow row = dtb.NewRow(); 
foreach (string key in drow.Keys) 
{ 
row[key] = drow[key]; 
} 
dtb.Rows.Add(row); 
} 
} 
return dtb; 
}

这样，就可以把数据无刷新的写入到数据库。
当然，如果我们有一个从数据库读取的datatable，如果通过json显示在前台呢。
首先，我们需要把datatable转换为json数据
[html]

/// <summary> 
/// DataTable转Json 
/// </summary> 
/// <param name="dtb"></param> 
/// <returns></returns> 
private string Dtb2Json(DataTable dtb) 
{ 
JavaScriptSerializer jss = new JavaScriptSerializer(); 
ArrayList dic = new ArrayList(); 
foreach (DataRow row in dtb.Rows) 
{ 
Dictionary<string, object> drow = new Dictionary<string, object>(); 
foreach (DataColumn col in dtb.Columns) 
{ 
drow.Add(col.ColumnName, row[col.ColumnName]); 
} 
dic.Add(drow); 
} 
return jss.Serialize(dic); 
} 
/// <summary> 
/// DataTable转Json 
/// </summary> 
/// <param name="dtb"></param> 
/// <returns></returns> 
private string Dtb2Json(DataTable dtb) 
{ 
JavaScriptSerializer jss = new JavaScriptSerializer(); 
ArrayList dic = new ArrayList(); 
foreach (DataRow row in dtb.Rows) 
{ 
Dictionary<string, object> drow = new Dictionary<string, object>(); 
foreach (DataColumn col in dtb.Columns) 
{ 
drow.Add(col.ColumnName, row[col.ColumnName]); 
} 
dic.Add(drow); 
} 
return jss.Serialize(dic); 
}

然后写回到前台
[html]

/// <summary> 
/// 处理异步请求 
/// </summary> 
private void ProcessRequest() 
{ 
Response.ContentType = "text/html"; 
string json = Request.Form["json"]; 
//反序列化DataTable 
DataTable newdtb = Json2Dtb(json); 
//序列化DataTable为JSON 
string back = Dtb2Json(newdtb); 
Response.Write(back); 
Response.End(); 
} 
/// <summary> 
/// 处理异步请求 
/// </summary> 
private void ProcessRequest() 
{ 
Response.ContentType = "text/html"; 
string json = Request.Form["json"]; 
//反序列化DataTable 
DataTable newdtb = Json2Dtb(json); 
//序列化DataTable为JSON 
string back = Dtb2Json(newdtb); 
Response.Write(back); 
Response.End(); 
}

在前台接受显示：
[html]

$(function() { 
//点击botton1 
$("#botton1").click(function() { 
createTable(json); 
}); 
}); 
//显示Json中的数据 
function createTable(json) { 
var table = $("<table border='1'></table>"); 
for (var i = 0; i < json.length; i++) { 
o1 = json[i]; 
var row = $("<tr></tr>"); 
for (key in o1) { 
var td = $("<td></td>"); 
td.text(o1[key].toString()); 
td.appendTo(row); 
} 
row.appendTo(table); 
} 
table.appendTo($("#back")); 
} 
$(function() { 
//点击botton1 
$("#botton1").click(function() { 
createTable(json); 
}); 
}); 
//显示Json中的数据 
function createTable(json) { 
var table = $("<table border='1'></table>"); 
for (var i = 0; i < json.length; i++) { 
o1 = json[i]; 
var row = $("<tr></tr>"); 
for (key in o1) { 
var td = $("<td></td>"); 
td.text(o1[key].toString()); 
td.appendTo(row); 
} 
row.appendTo(table); 
} 
table.appendTo($("#back")); 
}

这样，就完成了json向后台传输数据和显示后台数据了，当然，这种传输方式只是传输的一种，如果是简单的字符串也可以用get和post进行传输，但是，javascript本身具有不安全性和不稳定行，对于一些比较重要的数据，建议还是寻找一些更可靠的方法。