Get JSON Array and add items to Combobox in Delphi - json

Question

I have this JSON data:
[
{
"Name":"val1",
"Age":"25"
},
{
"Name":"Vtya",
"Age":"24"
},
{
"Name":"fgani",
"Age":"21"
},
{
"Name":"Shami",
"Age":"21"
},
{
"Name":"Slakf",
"Age":"22"
}
]
I wrote this code to parse the data and add the Name value to a Combobox:
procedure TJSON_Sample.FormCreate(Sender: TObject);
var
LJsonArray: TJSONArray;
LJsonValue, LITEM: TJSONValue;
lJsonData: string;
ljsPair: TJsonPair;
begin
LJsonArray := TJSONObject.ParseJSONValue(TEncoding.
Default.GetBytes(lJsonData), 0) as TJSONArray;//lJsonData contains the above mentioned JSON data
try
for LJsonValue in LJsonArray do
begin
for LITEM in TJSONArray(LJsonValue) do
begin
cmbBox_Name.Items.Add(TJsonPair(LITEM).JsonValue.Value);
end;
end;
finally
LJsonArray.Free;
end;
end;
When I run this, it is adding all of the Names and Ages to the Combobox. Can someone please help me in adding the Names only?

Answer 1

Your code is looping fine through your JSON. Your problem is to get just the 'Name' value when adding the item to the combobox.
Try GetValue('Name') instead of the whole JSONValue.Value.
procedure TJSON_Sample.FormCreate(Sender: TObject);
var
LJsonArray: TJSONArray;
LJsonValue, LITEM: TJSONValue;
lJsonData: string;
ljsPair: TJsonPair;
begin
LJsonArray := TJSONObject.ParseJSONValue(TEncoding.
Default.GetBytes(lJsonData), 0) as TJSONArray;//lJsonData contains the above mentioned JSON data
try
for LJsonValue in LJsonArray do
begin
for LITEM in TJSONArray(LJsonValue) do
begin
cmbBox_Name.Items.Add(TJsonObject(LITEM).GetValue('Name').Tostring);
end;
end;
finally
LJsonArray.Free;
end;
end;

Answer 2

This Solved my request
procedure TJSON_Sample.FormCreate(Sender: TObject);
var
LITEM, lJsonValue: TJSONValue;
lJsonData: string;
begin
lJsonValue := TJSONObject.ParseJSONValue(TEncoding.
Default.GetBytes(lJsonData), 0);//lJsonData contains the above mentioned JSON data
if lJsonValue <> nil then
try
begin
for LITEM in lJsonValue as TJSONArray do
begin
cmbBox_Name.Items.Add(((LITEM as TJSONObject).Get('Name') .JsonValue as TJSONString).Value);
end;
end;
finally
lJsonValue.Free;
end;
end;

Answer 3

I would consider using the Items.AddObject method instead, and use Items.Object[ComboBox1.ItemIndex] on the OnChange event of the combo-box.

Answer 4

Here is almost the same code, but I add BeginUpdate/EndUpdate for combobox items and use generic methods to avoid type casting.
procedure TJSON_Sample.FormCreate(Sender: TObject);
var
LJson, LItem: TJSONValue;
lJsonData: string;
begin
cmbBox_Name.Items.BeginUpdate;
try
cmbBox_Name.Items.Clear;
LJson := TJSONObject.ParseJSONValue(TEncoding.
Default.GetBytes(lJsonData), 0);//lJsonData contains the above mentioned JSON data
if Assigned(LJson) then
begin
for LItem in LJson as TJSONArray do
cmbBox_Name.Items.Add(LItem.GetValue<string>('Name'));
end;
finally
cmbBox_Name.Items.EndUpdate;
end;
end;