Conversion de données en JSON en C #
- Je veux obtenir des enregistrements de la base de données dans un
DataTable. - Convertissez ensuite la
DataTableen objet JSON. - Renvoie l'objet JSON à ma fonction JavaScript.
J'utilise this code en appelant:
string result = JsonConvert.SerializeObject(DatatableToDictionary(queryResult, "Title"), Newtonsoft.Json.Formatting.Indented);
Pour convertir un DataTable en JSON, cela fonctionne correctement et renvoie les éléments suivants:
{
"1": {
"viewCount": 703,
"clickCount": 98
},
"2": {
"viewCount": 509,
"clickCount": 85
},
"3": {
"viewCount": 578,
"clickCount": 86
},
"4": {
"viewCount": 737,
"clickCount": 108
},
"5": {
"viewCount": 769,
"clickCount": 130
}
}
Mais je voudrais qu'il retourne ce qui suit:
{"records":[
{
"Title": 1,
"viewCount": 703,
"clickCount": 98
},
{
"Title": 2,
"viewCount": 509,
"clickCount": 85
},
{
"Title": 3,
"viewCount": 578,
"clickCount": 86
},
{
"Title": 4,
"viewCount": 737,
"clickCount": 108
},
{
"Title": 5,
"viewCount": 769,
"clickCount": 130
}
]}
Comment puis-je faire ceci?
Cet extrait de code de Convertir une chaîne de caractères en JSON en C #, VB.NET pourrait vous aider ... .. Il utilise System.Web.Script.Serialization.JavaScriptSerializer pour sérialiser le contenu au format JSON:
public string ConvertDataTabletoString()
{
DataTable dt = new DataTable();
using (SqlConnection con = new SqlConnection("Data Source=SureshDasari;Initial Catalog=master;Integrated Security=true"))
{
using (SqlCommand cmd = new SqlCommand("select title=City,lat=latitude,lng=longitude,description from LocationDetails", con))
{
con.Open();
SqlDataAdapter da = new SqlDataAdapter(cmd);
da.Fill(dt);
System.Web.Script.Serialization.JavaScriptSerializer serializer = new System.Web.Script.Serialization.JavaScriptSerializer();
List<Dictionary<string, object>> rows = new List<Dictionary<string, object>>();
Dictionary<string, object> row;
foreach (DataRow dr in dt.Rows)
{
row = new Dictionary<string, object>();
foreach (DataColumn col in dt.Columns)
{
row.Add(col.ColumnName, dr[col]);
}
rows.Add(row);
}
return serializer.Serialize(rows);
}
}
}
Nous pouvons accomplir la tâche de deux manières simples: l’une en utilisant Json.NET dll et l’autre en utilisant la classe StringBuilder.
Utilisation de Newtonsoft Json.NET
string JSONresult;
JSONresult = JsonConvert.SerializeObject(dt);
Response.Write(JSONresult);
Lien de référence: Newtonsoft: Convertir DataTable en objet JSON en ASP.Net C #
Utilisation de StringBuilder
public string DataTableToJsonObj(DataTable dt)
{
DataSet ds = new DataSet();
ds.Merge(dt);
StringBuilder JsonString = new StringBuilder();
if (ds != null && ds.Tables[0].Rows.Count > 0)
{
JsonString.Append("[");
for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
{
JsonString.Append("{");
for (int j = 0; j < ds.Tables[0].Columns.Count; j++)
{
if (j < ds.Tables[0].Columns.Count - 1)
{
JsonString.Append("\"" + ds.Tables[0].Columns[j].ColumnName.ToString() + "\":" + "\"" + ds.Tables[0].Rows[i][j].ToString() + "\",");
}
else if (j == ds.Tables[0].Columns.Count - 1)
{
JsonString.Append("\"" + ds.Tables[0].Columns[j].ColumnName.ToString() + "\":" + "\"" + ds.Tables[0].Rows[i][j].ToString() + "\"");
}
}
if (i == ds.Tables[0].Rows.Count - 1)
{
JsonString.Append("}");
}
else
{
JsonString.Append("},");
}
}
JsonString.Append("]");
return JsonString.ToString();
}
else
{
return null;
}
}
Ceci a une approche similaire à la réponse acceptée, mais utilise LINQ pour convertir les données en listes en une seule ligne de code.
//convert datatable to list using LINQ. Input datatable is "dt", returning list of "name:value" tuples
var lst = dt.AsEnumerable()
.Select(r => r.Table.Columns.Cast<DataColumn>()
.Select(c => new KeyValuePair<string, object>(c.ColumnName, r[c.Ordinal])
).ToDictionary(z=>z.Key,z=>z.Value)
).ToList();
//now serialize it
var serializer = new System.Web.Script.Serialization.JavaScriptSerializer();
return serializer.Serialize(lst);
C'est un moyen extrêmement utile d'énumérer un datatable, ce qui prend normalement une tonne de codage! Voici quelques variations:
//convert to list with array of values for each row
var list1 = dt.AsEnumerable().Select(r => r.ItemArray.ToList()).ToList();
//convert to list of first column values only
var list2 = dt.AsEnumerable().Select(r => r.ItemArray[0]).ToList();
// parse a datatable with conditions and get CSV string
string MalesOver21 = string.Join(",",
dt.AsEnumerable()
.Where(r => r["GENDER"].ToString()=="M" && r.Field<int>("AGE")>21)
.Select(r => r.Field<string>("FULLNAME"))
);
Une autre manière sans utiliser le sérialiseur javascript:
public static string DataTableToJSON(DataTable Dt)
{
string[] StrDc = new string[Dt.Columns.Count];
string HeadStr = string.Empty;
for (int i = 0; i < Dt.Columns.Count; i++)
{
StrDc[i] = Dt.Columns[i].Caption;
HeadStr += "\"" + StrDc[i] + "\":\"" + StrDc[i] + i.ToString() + "¾" + "\",";
}
HeadStr = HeadStr.Substring(0, HeadStr.Length - 1);
StringBuilder Sb = new StringBuilder();
Sb.Append("[");
for (int i = 0; i < Dt.Rows.Count; i++)
{
string TempStr = HeadStr;
for (int j = 0; j < Dt.Columns.Count; j++)
{
TempStr = TempStr.Replace(Dt.Columns[j] + j.ToString() + "¾", Dt.Rows[i][j].ToString().Trim());
}
//Sb.AppendFormat("{{{0}}},",TempStr);
Sb.Append("{"+TempStr + "},");
}
Sb = new StringBuilder(Sb.ToString().Substring(0, Sb.ToString().Length - 1));
if(Sb.ToString().Length>0)
Sb.Append("]");
return StripControlChars(Sb.ToString());
}
//To strip control characters:
//A character that does not represent a printable character but //serves to initiate a particular action.
public static string StripControlChars(string s)
{
return Regex.Replace(s, @"[^\x20-\x7F]", "");
}
Vous pouvez utiliser la même manière que celle spécifiée par Alireza Maddah et si vous voulez utiliser deux tables de données dans un tableau json, procédez comme suit:
public string ConvertDataTabletoString()
{
DataTable dt = new DataTable();
DataTable dt1 = new DataTable();
using (SqlConnection con = new SqlConnection("Data Source=SureshDasari;Initial Catalog=master;Integrated Security=true"))
{
using (SqlCommand cmd = new SqlCommand("select title=City,lat=latitude,lng=longitude,description from LocationDetails", con))
{
con.Open();
SqlDataAdapter da = new SqlDataAdapter(cmd);
da.Fill(dt);
System.Web.Script.Serialization.JavaScriptSerializer serializer = new System.Web.Script.Serialization.JavaScriptSerializer();
List<Dictionary<string, object>> rows = new List<Dictionary<string, object>>();
Dictionary<string, object> row;
foreach (DataRow dr in dt.Rows)
{
row = new Dictionary<string, object>();
foreach (DataColumn col in dt.Columns)
{
row.Add(col.ColumnName, dr[col]);
}
rows.Add(row);
}
SqlCommand cmd1 = new SqlCommand("_another_query_", con);
SqlDataAdapter da1 = new SqlDataAdapter(cmd1);
da1.Fill(dt1);
System.Web.Script.Serialization.JavaScriptSerializer serializer1 = new System.Web.Script.Serialization.JavaScriptSerializer();
Dictionary<string, object> row1;
foreach (DataRow dr in dt1.Rows) //use the old variable rows only
{
row1 = new Dictionary<string, object>();
foreach (DataColumn col in dt1.Columns)
{
row1.Add(col.ColumnName, dr[col]);
}
rows.Add(row1); // Finally You can add into old json array in this way
}
return serializer.Serialize(rows);
}
}
}
La même manière peut être utilisée pour autant de tables de données que vous le souhaitez.
Convertissez les données en JSON avec C # .net
public static object DataTableToJSON(DataTable table)
{
var list = new List<Dictionary<string, object>>();
foreach (DataRow row in table.Rows)
{
var dict = new Dictionary<string, object>();
foreach (DataColumn col in table.Columns)
{
dict[col.ColumnName] = (Convert.ToString(row[col]));
}
list.Add(dict);
}
JavaScriptSerializer serializer = new JavaScriptSerializer();
return serializer.Serialize(list);
}
Essayez cette fonction personnalisée.
public static string DataTableToJsonObj(DataTable dt)
{
DataSet ds = new DataSet();
ds.Merge(dt);
StringBuilder jsonString = new StringBuilder();
if (ds.Tables[0].Rows.Count > 0)
{
jsonString.Append("[");
for (int rows = 0; rows < ds.Tables[0].Rows.Count; rows++)
{
jsonString.Append("{");
for (int cols = 0; cols < ds.Tables[0].Columns.Count; cols++)
{
jsonString.Append(@"""" + ds.Tables[0].Columns[cols].ColumnName + @""":");
/*
//IF NOT LAST PROPERTY
if (cols < ds.Tables[0].Columns.Count - 1)
{
GenerateJsonProperty(ds, rows, cols, jsonString);
}
//IF LAST PROPERTY
else if (cols == ds.Tables[0].Columns.Count - 1)
{
GenerateJsonProperty(ds, rows, cols, jsonString, true);
}
*/
var b = (cols < ds.Tables[0].Columns.Count - 1)
? GenerateJsonProperty(ds, rows, cols, jsonString)
: (cols != ds.Tables[0].Columns.Count - 1)
|| GenerateJsonProperty(ds, rows, cols, jsonString, true);
}
jsonString.Append(rows == ds.Tables[0].Rows.Count - 1 ? "}" : "},");
}
jsonString.Append("]");
return jsonString.ToString();
}
return null;
}
private static bool GenerateJsonProperty(DataSet ds, int rows, int cols, StringBuilder jsonString, bool isLast = false)
{
// IF LAST PROPERTY THEN REMOVE 'COMMA' IF NOT LAST PROPERTY THEN ADD 'COMMA'
string addComma = isLast ? "" : ",";
if (ds.Tables[0].Rows[rows][cols] == DBNull.Value)
{
jsonString.Append(" null " + addComma);
}
else if (ds.Tables[0].Columns[cols].DataType == typeof(DateTime))
{
jsonString.Append(@"""" + (((DateTime)ds.Tables[0].Rows[rows][cols]).ToString("yyyy-MM-dd HH':'mm':'ss")) + @"""" + addComma);
}
else if (ds.Tables[0].Columns[cols].DataType == typeof(string))
{
jsonString.Append(@"""" + (ds.Tables[0].Rows[rows][cols]) + @"""" + addComma);
}
else if (ds.Tables[0].Columns[cols].DataType == typeof(bool))
{
jsonString.Append(Convert.ToBoolean(ds.Tables[0].Rows[rows][cols]) ? "true" : "fasle");
}
else
{
jsonString.Append(ds.Tables[0].Rows[rows][cols] + addComma);
}
return true;
}
Pour accéder à la valeur convertible datatable dans la méthode Json, suivez les étapes ci-dessous:
$.ajax({
type: "POST",
url: "/Services.asmx/YourMethodName",
data: "{}",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (data) {
var parsed = $.parseJSON(data.d);
$.each(parsed, function (i, jsondata) {
$("#dividtodisplay").append("Title: " + jsondata.title + "<br/>" + "Latitude: " + jsondata.lat);
});
},
error: function (XHR, errStatus, errorThrown) {
var err = JSON.parse(XHR.responseText);
errorMessage = err.Message;
alert(errorMessage);
}
});
J'ai une fonction simple pour convertir datatable en chaîne json.
J'ai utilisé Newtonsoft pour générer une chaîne. Je n'utilise pas Newtonsoft pour sérialiser complètement Datatable. Soyez prudent à ce sujet.
Peut-être que cela peut être utile.
private string DataTableToJson(DataTable dt) {
if (dt == null) {
return "[]";
};
if (dt.Rows.Count < 1) {
return "[]";
};
JArray array = new JArray();
foreach(DataRow dr in dt.Rows) {
JObject item = new JObject();
foreach(DataColumn col in dt.Columns) {
item.Add(col.ColumnName, dr[col.ColumnName]?.ToString());
}
array.Add(item);
}
return array.ToString(Newtonsoft.Json.Formatting.Indented);
}
public static string ConvertIntoJson(DataTable dt)
{
var jsonString = new StringBuilder();
if (dt.Rows.Count > 0)
{
jsonString.Append("[");
for (int i = 0; i < dt.Rows.Count; i++)
{
jsonString.Append("{");
for (int j = 0; j < dt.Columns.Count; j++)
jsonString.Append("\"" + dt.Columns[j].ColumnName + "\":\""
+ dt.Rows[i][j].ToString().Replace('"','\"') + (j < dt.Columns.Count - 1 ? "\"," : "\""));
jsonString.Append(i < dt.Rows.Count - 1 ? "}," : "}");
}
return jsonString.Append("]").ToString();
}
else
{
return "[]";
}
}
public static string ConvertIntoJson(DataSet ds)
{
var jsonString = new StringBuilder();
jsonString.Append("{");
for (int i = 0; i < ds.Tables.Count; i++)
{
jsonString.Append("\"" + ds.Tables[i].TableName + "\":");
jsonString.Append(ConvertIntoJson(ds.Tables[i]));
if (i < ds.Tables.Count - 1)
jsonString.Append(",");
}
jsonString.Append("}");
return jsonString.ToString();
}
//Common DLL client, server
public class transferDataTable
{
public class myError
{
public string Message { get; set; }
public int Code { get; set; }
}
public myError Error { get; set; }
public List<string> ColumnNames { get; set; }
public List<string> DataTypes { get; set; }
public List<Object> Data { get; set; }
public int Count { get; set; }
}
public static class ExtensionMethod
{
public static transferDataTable LoadData(this transferDataTable transfer, DataTable dt)
{
if (dt != null)
{
transfer.DataTypes = new List<string>();
transfer.ColumnNames = new List<string>();
foreach (DataColumn c in dt.Columns)
{
transfer.ColumnNames.Add(c.ColumnName);
transfer.DataTypes.Add(c.DataType.ToString());
}
transfer.Data = new List<object>();
foreach (DataRow dr in dt.Rows)
{
foreach (DataColumn col in dt.Columns)
{
transfer.Data.Add(dr[col] == DBNull.Value ? null : dr[col]);
}
}
transfer.Count = dt.Rows.Count;
}
return transfer;
}
public static DataTable GetDataTable(this transferDataTable transfer, bool ConvertToLocalTime = true)
{
if (transfer.Error != null || transfer.ColumnNames == null || transfer.DataTypes == null || transfer.Data == null)
return null;
int columnsCount = transfer.ColumnNames.Count;
DataTable dt = new DataTable();
for (int i = 0; i < columnsCount; i++ )
{
Type colType = Type.GetType(transfer.DataTypes[i]);
dt.Columns.Add(new DataColumn(transfer.ColumnNames[i], colType));
}
int index = 0;
DataRow row = dt.NewRow();
foreach (object o in transfer.Data)
{
if (ConvertToLocalTime && o != null && o.GetType() == typeof(DateTime))
{
DateTime dat = Convert.ToDateTime(o);
row[index] = dat.ToLocalTime();
}
else
row[index] = o == null ? DBNull.Value : o;
index++;
if (columnsCount == index)
{
index = 0;
dt.Rows.Add(row);
row = dt.NewRow();
}
}
return dt;
}
}
//Server
[OperationContract]
[WebInvoke(Method = "GET", ResponseFormat = WebMessageFormat.Json, BodyStyle = WebMessageBodyStyle.WrappedRequest, UriTemplate = "json/data")]
transferDataTable _Data();
public transferDataTable _Data()
{
try
{
using (SqlConnection con = new SqlConnection(ConfigurationManager.AppSettings["myConnString"]))
{
con.Open();
DataSet ds = new DataSet();
SqlDataAdapter myAdapter = new SqlDataAdapter("SELECT * FROM tbGalleries", con);
myAdapter.Fill(ds, "table");
DataTable dt = ds.Tables["table"];
return new transferDataTable().LoadData(dt);
}
}
catch(Exception ex)
{
return new transferDataTable() { Error = new transferDataTable.myError() { Message = ex.Message, Code = ex.HResult } };
}
}
//Client
Response = Vossa.getAPI(serviceUrl + "json/data");
transferDataTable transfer = new JavaScriptSerializer().Deserialize<transferDataTable>(Response);
if (transfer.Error == null)
{
DataTable dt = transfer.GetDataTable();
dbGrid.ItemsSource = dt.DefaultView;
}
else
MessageBox.Show(transfer.Error.Message, "Error", MessageBoxButton.OK, MessageBoxImage.Error);
Passez le datable à cette méthode, elle retournerait json String.
public DataTable GetTable()
{
string str = "Select * from GL_V";
OracleCommand cmd = new OracleCommand(str, con);
cmd.CommandType = CommandType.Text;
DataTable Dt = OracleHelper.GetDataSet(con, cmd).Tables[0];
return Dt;
}
public string DataTableToJSONWithJSONNet(DataTable table)
{
string JSONString = string.Empty;
JSONString = JsonConvert.SerializeObject(table);
return JSONString;
}
public static DataSet GetDataSet(OracleConnection con, OracleCommand cmd)
{
// create the data set
DataSet ds = new DataSet();
try
{
//checking current connection state is open
if (con.State != ConnectionState.Open)
con.Open();
// create a data adapter to use with the data set
OracleDataAdapter da = new OracleDataAdapter(cmd);
// fill the data set
da.Fill(ds);
}
catch (Exception ex)
{
throw;
}
return ds;
}
Avec Cinchoo ETL - une bibliothèque open source, vous pouvez exporter facilement DataTable vers JSON avec quelques lignes de code.
StringBuilder sb = new StringBuilder();
string connectionstring = @"Data Source=(localdb)\MSSQLLocalDB;Initial Catalog=Northwind;Integrated Security=True";
using (var conn = new SqlConnection(connectionstring))
{
conn.Open();
var comm = new SqlCommand("SELECT * FROM Customers", conn);
SqlDataAdapter adap = new SqlDataAdapter(comm);
DataTable dt = new DataTable("Customer");
adap.Fill(dt);
using (var parser = new ChoJSONWriter(sb))
parser.Write(dt);
}
Console.WriteLine(sb.ToString());
Sortie:
{"Customer": [
{
"CustomerID": "ALFKI",
"CompanyName": "Alfreds Futterkiste",
"ContactName": "Maria Anders",
"ContactTitle": "Sales Representative",
"Address": "Obere Str. 57",
"City": "Berlin",
"Region": null,
"PostalCode": "12209",
"Country": "Germany",
"Phone": "030-0074321",
"Fax": "030-0076545"
},
{
"CustomerID": "ANATR",
"CompanyName": "Ana Trujillo Emparedados y helados",
"ContactName": "Ana Trujillo",
"ContactTitle": "Owner",
"Address": "Avda. de la Constitución 2222",
"City": "México D.F.",
"Region": null,
"PostalCode": "05021",
"Country": "Mexico",
"Phone": "(5) 555-4729",
"Fax": "(5) 555-3745"
}
]}
essayez ceci (ExtensionMethods):
public static string ToJson(this DataTable dt)
{
List<Dictionary<string, object>> lst = new List<Dictionary<string, object>>();
Dictionary<string, object> item;
foreach (DataRow row in dt.Rows)
{
item = new Dictionary<string, object>();
foreach (DataColumn col in dt.Columns)
{
item.Add(col.ColumnName, (Convert.IsDBNull(row[col]) ? null : row[col]));
}
lst.Add(item);
}
return Newtonsoft.Json.JsonConvert.SerializeObject(lst);
}
et utilise:
DataTable dt = new DataTable();
.
.
.
var json = dt.ToJson();