Try
...
...
Except
...
End;
Exception
Try
...
...
Except
on E:Exception do
begin
MessageBox(Handle, PWideChar(E.Message), PWideChar(E.Class), MB_ICONError);
end
End;
2021年9月12日 星期日
2021年9月2日 星期四
Delphi DataSet和JSON互轉函式
一、DataSet轉JSON
//1）資料集轉換為JSON字串：//需USES System.JSON;
function DataSetToJson(ADataset: TDataSet): string;
var
LRecord: string;
LField: TField;
i: integer;
begin
Result := '';
if (not ADataset.Active) or (ADataset.IsEmpty) then
Exit;
Result := '[';
ADataset.DisableControls;
ADataset.First;
while not ADataset.Eof do
begin
for i := 0 to ADataset.FieldCount - 1 do
begin
LField := ADataset.Fields[i];
if LRecord = '' then
LRecord := '{"' + LField.FieldName + '":"' + LField.Text + '"'
else
LRecord := LRecord + ',"' + LField.FieldName + '":"' + LField.Text + '"';
if i = ADataset.FieldCount - 1 then
begin
LRecord := LRecord + '}';
if Result = '[' then
Result := Result + LRecord
else
Result := Result + ',' + LRecord;
LRecord := '';
end;
end;
ADataset.Next;
end;
ADataset.EnableControls;
Result := Result + ']';
end;
二、JSON轉DataSet
//2）JSON字串轉換為資料集：procedure JsonToDataSet(AJson: string; ADataset: TDataSet);
var
jDataSet: TJSONArray;
jRecord: TJSONObject;
i, j: Integer;
begin
if (AJson = '') or (ADataset = nil) or (not ADataset.Active) then
Exit;
jDataSet := TJSONArray.Create;
jDataSet := TJSONObject.ParseJSONValue(AJson, True) as TJSONArray;
while not ADataset.Eof do
ADataset.Delete;
for i := 0 to jDataSet.Size - 1 do
begin
ADataset.Append;
jRecord := jDataSet.Get(i) as TJSONObject;
for j := 0 to ADataset.FieldCount - 1 do
begin
if ADataset.Fields[j].ReadOnly then
Continue;
ADataset.Fields[j].AsString := jRecord.GetValue(ADataset.Fields[j].FieldName).Value;
end;
ADataset.Post;
end;
end;
轉貼至: https://www.itread01.com/content/1548927014.html，(因應語法及版本做適當的修正)
Json To ClientDataset
procedure JsonToClientDataset(AJson:String; AClientDataset:TClientDataset);
var
jDataSet: TJSONArray;
jRecord: TJSONObject;
i, j: Integer;
procedure CreateClientDataset;
var k, iFieldCount:Integer;
sFieldName:String;
begin
AClientDataset.Close;
AClientDataset.Fields.Clear;
AClientDataset.FieldDefs.Clear;
jRecord := jDataSet.Get(0) as TJSONObject;
iFieldCount := jRecord.Count; //欄位數
for k := 0 to iFieldCount-1 do
begin
sFieldName := Trim(jRecord.Pairs[k].JsonString.Value);
AClientDataset.FieldDefs.Add(sFieldName, ftString, 2000);
end;
AClientDataset.CreateDataSet;
end;
begin
if (AJson = '') or (AClientDataset = nil) then
Exit;
jDataSet := TJSONArray.Create;
jDataSet := TJSONObject.ParseJSONValue(AJson, True) as TJSONArray;
//
CreateClientDataset;
//
for i := 0 to jDataSet.Size - 1 do
begin
AClientDataset.Append;
jRecord := jDataSet.Get(i) as TJSONObject;
for j := 0 to AClientDataset.FieldCount - 1 do
begin
AClientDataset.Fields[j].AsString := jRecord.GetValue(AClientDataset.Fields[j].FieldName).Value;
jDataSet.Count;
end;
AClientDataset.Post;
end;
end;
2021年9月1日 星期三
截取 ADO 錯誤訊息
procedure ADOConnection1ExecuteComplete(Connection: TADOConnection; RecordsAffected: Integer;
const Error: Error; var EventStatus: TEventStatus; const Command: _Command; const Recordset: _Recordset);
begin
//ADO 錯誤訊息
if EventStatus=esErrorsOccured then
begin
ShowMessage(Error.Description);
end;
end;
const Error: Error; var EventStatus: TEventStatus; const Command: _Command; const Recordset: _Recordset);
begin
//ADO 錯誤訊息
if EventStatus=esErrorsOccured then
begin
ShowMessage(Error.Description);
end;
end;
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