The simple designer is almost done; it is only missing the code used to create new fields in the report.
If you look at the code we are using for the toolbar event handler, you will see that it set the CreateFieldInfo property on the designer and says to wait for the CreateField event from the designer.
Add the following code to create new fields in the report:
' handle clicks on toolbar buttons
Private Sub _tb_ButtonClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.ToolBarButtonClickEventArgs) Handles _tb.ButtonClick
' …
' add fields
' (just set create info and wait for CreateField event from designer)
If e.Button.Equals(_btnAddField) Then
_c1rd.CreateFieldInfo = e.Button
If e.Button.Equals(_btnAddLabel) Then
_c1rd.CreateFieldInfo = e.Button
End Sub
• C#
// handle clicks on toolbar buttons
private void _tb_ButtonClick(object sender, System.Windows.Forms.ToolBarButtonClickEventArgs e)
{
// …
// add fields
// (just set create info and wait for CreateField event from designer)
if (e.Button == _btnAddField) _c1rd.CreateFieldInfo = e.Button;
if (e.Button == _btnAddLabel) _c1rd.CreateFieldInfo = e.Button;
}
The CreateFieldInfo property can be set to any non-null object to indicate to the designer that you want to create a new field. The designer doesn't know what type of field you want to create or how you want to initialize it, so it tracks the mouse and allows the user to draw the field outline on a section. It then fires the CreateField event passing the information you need to create the field yourself.
Add the following code to handle the CreateField event:
Dim _ctr As Integer
Private Sub _c1rd_CreateField(ByVal sender As Object, ByVal e As C1.Win.C1ReportDesigner.CreateFieldEventArgs) Handles _c1rd.CreateField
' save undo info
_c1rd.UndoStack.SaveState()
' add label field
_ctr = _ctr + 1
Dim fieldName As String = String.Format("NewField{0}", _ctr)
Dim fieldText As String = fieldName
Dim f As Field = e.Section.Fields.Add(fieldName, fieldText, e.FieldBounds)
' if this is a calculated field,
' change the Text and Calculated properties
If e.CreateFieldInfo.Equals(_btnAddField) Then
Dim fieldNames As String() = _c1rd.Report.DataSource.GetDBFieldList(True)
If (fieldNames.Length > 0) Then
f.Text = fieldNames(0)
f.Calculated = True
End If
End If
End Sub
• C#
int _ctr = 0;
private void _c1rd_CreateField(object sender,
C1.Win.C1ReportDesigner.CreateFieldEventArgs e)
{
// save undo info
_c1rd.UndoStack.SaveState();
// add label field
string fieldName = string.Format("NewField{0}", ++_ctr);
string fieldText = fieldName;
Field f = e.Section.Fields.Add(fieldName, fieldText, e.FieldBounds);
// if this is a calculated field,
// change the Text and Calculated properties
if (e.CreateFieldInfo == _btnAddField)
{
string[] fieldNames = _c1rd.Report.DataSource.GetDBFieldList(true);
if (fieldNames.Length > 0)
{
f.Text = fieldNames[0];
f.Calculated = true;
}
}
}
Note how the code starts by calling the SaveState method on the designer, so the user can undo the field creation. After that, the field is created, and the CreateFieldInfo parameter is used to customize the new field and make it behave as a label or as a calculated field.
That concludes the simple designer application: an introduction to the operation of the C1ReportDesigner control.
|
