I have a TcxGrid component to show data of a MS Access table. One of this columns have a picture. The column "Properties" of this column is marked as "ButtonEdit".
I don't want to use a BlobEdit. I want to create another form, for display this picture. It will be opened by OnButtonClick() event of the grid column. But, I don't know how to get the column content (as TStream or other type), or the column name/field name in the OnButtonClick() event. I can't fix the column name, because it's a "generic" grid for show any Access table.
How can I do it?
It will be nice to understand your question better if you can post your code. But offcourse You can get column contents easily by using FieldByName method. Try to use that.
You did not say how you load the data into the grid, but to get the cell content you can use:
VarAsType(cxGrid1TableView1.DataController.Values[cxGrid1TableView1.Controller.FocusedRecordIndex,cxGrid1TableView1.Controller.FocusedColumnIndex],varString)
Related
I'm new to delphi and have created an SQL query which displays the results of a search entered by the user through an edit box (showing data from 2 related tables) in a dbGrid.
The dbgrid displays no data until a search has been made and then the results of that search are displayed, however i was wondering whether it was possible to show all the related data in the dbgrid as if it were a table and the search then simply selects from it?
thanks
You could display all the data in the table. Then write an onExit event handler for your edit box which would look something like this (assuming that the string which you are entering in the edit box is supposed to match the value in the 'name' field of the query)
query.locate ('name', edit1.text, [loPartialValue]);
This will cause the dbgrid's cursor to jump to the first line which matches the string in the edit box.
Instead of using the OnExit event, you could also use the OnChange event of the edit box, but this would mean a search after every key stroke.
Your question was a bit vague so it's difficult to give a specific answer.
I am trying to create a Delphi grid to allow display and edit in a db grid of data that might have a different data type on each row. I would like to display a specific control for each data type, e.g. when the data type is DateTime, I want to display my custom edit control that allows typing a date in or popping up a calendar.
The data looks something like this:
Name DataType DateValue StringValue BooleanValue
---------------------------------------------------------
A Date 1/1/2007
B String asdf
C Boolean True
...and in the db, this table has a column for each possible type of value. So, there is a BooleanValue column, DateValue, etc.
What I would like to do is display a single 'Value' column in the grid that displays the appropriate edit control depending on what the 'DataType' is for that row. So, the grid should look like :
Name DataType Value
---------------------------
A Date 1/1/2007
B String asdf
C Boolean True
It seems I will need to display a different edit control (to allow the user to edit the Value column) for each row dynamically based on the value of the DataType column. I know there are more advanced grids out there that handle this sort of problem, but the powers that be will not allow anything but what is available out-of-the-box with Delphi.
Any ideas on how to make something like this work?
Personally, I would not go for editing directly inside the TDBGrid in this case, since your Table is not DB normalized (I don't use it in any case actually). I would have used a Calculated field to display the desired value in the grid, And dynamically created the TDBxxxEdits on the form for each field type (How about your own TDBTreeEdit for example, a TDBRichEdit, or a DB Image pickup editor, etc...?).
In case you do want to use your own controls on the TDBGrid, and replace the default TInplaceEdit editor, you can refer the following article: Adding components to a DBGrid, and a related article: Displaying and editing MEMO fiels in Delphi's TDBGrid
Displaying all of the data in the same column is quite easy. You can simply add a calculated string field, and change the value according to what you are storing in that row.
The editing is quite a bit more complicated. If you want to have an in-place editor, you are in for a world of hurt... I've done it, it's a pain, and takes a lot of time. If you want to display a dialog to edit the value, that's much easier. You can add a column objects to the grid and you can setup the column you have attached to the calc field to display a button. When the button is clicked you simply display the editing dialog needed for that row, and commit the edits when the dialog is closed.
There are other ways to get this done, but I would say the above would be the shortest way. Other ways may include custom draw events to display your data in one column, intercept clicks to create your own editor, etc, etc, etc...
after add calculated fields .
Sample:
procedure OnCalculate(DataSet:TDataSet);
begin
case IndexText(DataSet['ValueType'],['Date','String','Boolean']) of
0:DataSet['DateValue']:=StrToDateTime(DataSet['Value']); // also converting
1:DataSet['StringValue']:=DataSet['Value'];
2:DataSet['BooleanValue']:= MatchText(DataSet['Value'],['1','True','T','Y','Yes']);
{etc datatypes}
end;
end;
I'm looking to add hover text to a given column in a grid with row specific data. I'm planning on overriding the mouse-enter event, but I'm unsure how to populate a Tooltip and have it display next to the mouse.
Any direction would be appreciated, thanks!
**Edit: It looks like the method to override is actually called "Tooltip". I was able to override this and get a tooltip to display.
The question remains: How to access the current row's data for the column that the Tooltip is on?
To show a tooltip with the description of the foreign key field, the following must be met:
Base your field on an extended data type
Put a relation on the extended data type
Have the relation point to a base table
Set the TitleField1 and TitleField2 attributes on the base table
Have a unique index on the key fields of your base table
You can put the relation on the (transaction) table instead of the extended data type.
Do that in AX 2012 or if the relation has more than one field to join.
Here's the tooltip code that I ended up using:
public str toolTip()
{
;
return tblYourTable::find(this.value()).Description;
}
**Edit per Jan's comment to greatly simplify code
as a follow up question to my previous one. I can edit the DBMemo's now.
However they always seem to have the values from the very first row in the table.
I've done a DBMemo1.Text = ''
I've done a locate on the DataSet underneath to see if it would clear it. but no.
What do I need to do to have that empty and type something in to insert it?
Like any other data-aware control, the memo is bound to the values from the current row in the table. Try putting a TDBNavigator and a TDBGrid on your form so you can play around with the current record and see what's going on. If you want to create an empty row to insert into it, you need to call Insert or Append on the dataset, or click the + symbol on the TDBNavigator. This creates a new, blank row in the dataset and sets it to the current row.
You probably need to add a new row to the dataset.
DataSet.Append;
I saw your last question and I believe the following tutorial will help you:
http://delphi.about.com/od/database/a/databasecourse_2.htm
To clear the text from DBMemo you should either Insert, Append or Delete+Insert/Append on your data set. Mason explained you very well that you need to have a 'navigator' for your data set. Follow the examples provided here:
http://delphi.about.com/od/database/ss/dbcourse_browse.htm
Best regards,
Radu
So I'm messing around with a new project in Delphi 2009 and the default components that can be dropped onto a form for accessing data consist of a SQLConnection, DataSource and SQLQuery. If I add a simple select to the query component, say:
select name from customers
and then drop a DBComboBox on the form and link it up with the DataSource I get a single record in the combo box. After using Google for half and hour to figure out what I was doing wrong it looks like you have to manually add some code to your project which loops through the dataset and adds all the records to the drop down box. Something like:
while not SQLQuery.eof do
begin
DBComboBox.items.add(SQLQuery.fieldbyname('name').asstring);
SQLQuery.next;
end;
And that actually sort of works, but then you get a list in the drop down which you can't actually select anything from. Regardless of the result though I'm wondering why would you even use a DBComboBox if you have to manually add the result of your query to it? Seems to me that if it doesn't automatically populate the db combo box with the result of the query then we might as well be using a non-data-aware component like tcombobox.
I guess what I'm asking is why does it work this way? Isn't the purpose of data aware drag-and-drop controls to minimize the amount of actual written code and speed development? Is there a method that I'm missing that is supposed to make this easier?
A TDBComboBox doesn't get its list of values from the database; it gets its current value from the database. Link it to a field in your dataset, and when you change the active record, the combo box's current value will change. Change the combo box's current value, and the corresponding field's value will change.
If you want to get the list of values from the database as well, then use a TDBLookupComboBox.
This is all covered in the help:
Using TDBListBox and TDBComboBox
Displaying and Editing Data in Lookup List and Combo Boxes
Defining a Lookup List Column
I think you want the TDBLookupComboBox because that allows you to lookup from a list of items where the list comes from a dataset.
In the TDBComboBox, the list is just a TStrings manually filled with data.
--jeroen
DbCombox is a dbaware version of the standard combobox component.