I'm struggling getting a certain column within my DataGridView to display things right. It had been working and I must have broken something subtly, now all I get is an empty string. Does anyone know why this might be?
// this inherits from DataGridView
this.Rows.Add(new object[]
{
"test",
new CustomType("A", "1")
});
CustomType()
{
...
public override String ToString()
{
return this.String1 + ":" + this.String2;
}
}
The result of such a thing is my Row.Cells[1].Value is "A : 1". However the FormattedValue is always blank...
I can't tell if your way is incorrect, but you seem to be doing it differently than the API reference for DataGridView.FormattedValue would suggest.
Did you try it that way?
Ok, I managed to find the cause of this... Unfortunately it was an annoying designer change whereby it lost the information that the column was bound to when I removed a different control from there.
This means that the databinding was not set, and hence it didn't know how to display the value.
Related
This question is an offshoot of: Localizing ObjectListView OLVColumn, impossible due to Empty Name property
For simplicity's sake, let's say my ObjectListView contains car information. User A wants to display only Make and Model columns. User B only wants to display Model and Year columns. These preferences would be saved to/loaded from an .ini file on the users' local machines.
I cannot loop through the columns of the ObjectListView and do if (col.Name == colNameFromIni) { col.Visible == true; } because the .Name property of every column is an empty string ("") and does not get serialized to the designer codebehind file. This never happens with any other Winforms control (Label, Button, etc.) They always get their .Name written to the designer codebehind.
In some sense, this is a flaw in Winforms itself, because OLVColumn inherits from System.Windows.Forms.ColumnHeader, and a traditional ListView has exactly the same problem. .Name is always an empty string for all columns.
I would like to patch our local build of ObjectListView.dll to force populate the .Name property, but I can't figure out how Winforms automagically knows the name of every control on the form. It somehow(?) knows the names of the OLVColumn objects since it can display them in the Edit Columns... dialog on the ObjectListView's context menu. I'm also a little fuzzy on where the best spot is to plug this in.
(Yes, per linked question at top I know that as a last resort, I can hardcode colXX.Name = "colXX"; for all columns in my source code, but future column additions are likely to get overlooked and a programmatic solution is much preferred.)
(See also: https://sourceforge.net/p/objectlistview/bugs/160/ : the ObjectListView author declared this a wont-fix so it is up to me (or us), I guess.)
As you point out, this is a bug which is not with the ObjectListView, but the underlying component. And a bug which is around since at least 2008! Therefore, I doubt it will ever be fixed by MS.
Actually, it is a problem with the Autogenerated code in the designer.
If you look at other components such as a button, then the autogenerated code adds a name such as this;
//
// button2
//
this.button2.Location = new System.Drawing.Point(458, 199);
this.button2.Name = "button2";
...
But for ColumnHeader (Listview) and OLVColumn (ObjectListView), then this is not done, so then you end up with this.
//
// olvColumn1
//
this.olvColumn1.AspectName = "Name";
this.olvColumn1.Text = "Name";
If you manually add the line
this.olvColumn1.Text = "olvColumn1";
Then the "problem" is solved.
Of course, you can't do this, because the designer will override the autogenerated code when you make any changes, and then you will lose these manually added lines. It is also not sustainable.
So I'm afraid you need to code around this with some kind of ugly solution. Some options are:
Use the Tag to store the name and compare against this.
Use the text instead of the name (not possible if you have multi
language support!)
Code the names column manually in the Constructor
Set the Text to be something like "ColName;ColText" and then in your
code separate these out.
I have done option 3 in the past, but only I was maintaining the code, so this was easy.
What you could do to ensure you don't have discrepancies is to add a check in your constructor to compare the actual number of columns with the number you expect (hard coded for), and throw an exception if they don't match. Also, not the best, but another way to highlight and reduce errors.
The workaround for this is to get the OLVColumns via reflection and set their column's Name property at runtime. Every OLVColumn is a form-level field, so just pick them out of the list returned by GetFields().
Dim allFieldInfos As FieldInfo() = GetType(FrmMain).GetFields(BindingFlags.NonPublic or BindingFlags.Instance)
For Each fi As FieldInfo In allFieldInfos
If fi.FieldType Is GetType(OLVColumn) Then
Dim instance As OLVColumn = fi.GetValue(Me)
For Each col As OLVColumn In fdlvMain.AllColumns
If ReferenceEquals(col, instance) Then
col.Name = fi.Name
End If
Next
End If
Next
Anyone knows how to get list of selected CheckBoxList values from Umbraco using ContentService?
I use contentService.GetValue("currencies")
and I get string with numbers and commas something like "154,155,156,157"
How can I get actual values?
Does anyone know how to do it using DataTypeService?
As it was mentioned above, you can use Umbraco helpers method to retrieve string value for the PreValue id.
Umbraco.GetPreValueAsString([PreValueId])
You can find more about it here: https://our.umbraco.org/documentation/reference/querying/umbracohelper/#getprevalueasstring-int-prevalueid
It's calling database directly through the DataTypeService behind the scene. It's worth to reconsider it and close it on another type of property / data type to avoid calling database on the frontend layer and just retrieve data from IPublishedContent cached model.
Read also about common pitfalls and anti-patterns in Umbraco: https://our.umbraco.org/documentation/Reference/Common-Pitfalls/
Those are prevalues.
From that given string, you have to split those and get the real value by calling one of umbraco library umbraco.library.GetPreValueAsString(123);
For example.
foreach(var item in contentService.GetValue("currencies").Split(',')) {
var realValue = umbraco.library.GetPreValueAsString(int.Parse(item);
}
You have 2 nulls because prevalues sometimes has blank values on it, like "121,56,,15,145".
You need then to modify your split code like this
foreach (var item in value.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries))
{
}
StringSplitOptions.RemoveEmptyEntries will ignore empty spaces.
I'm trying to create a WPF MarkupExtension class that provides translated text from my text translation class. The translation stuff works great, but requires a static method call with a text key to return the translated text. Like this:
ImportLabel.Text = Translator.Translate("import files");
// will be "Dateien importieren" in de or "Import files" in en
Its speciality is that it accepts a counting value to provide better wordings.
ImportLabel.Text = Translator.Translate("import n files", FileCount);
// will be "Import 7 files" or "Import 1 file"
Another example: If something takes yet 4 minutes, it's a different word than if it only takes one minute. If a text key "minutes" is defined as "Minuten" for any number and as "Minute" for a count of 1, the following method call will return the right word to use:
Translator.Translate("minutes", numberOfMinutes)
// will be "minute" if it's 1, and "minutes" for anything else
Now in a WPF application, there's a lot of XAML code and that contains lots of literal texts. To be able to translate them without getting nuts, I need a markup extension which I can pass my text key and that will return the translated text at runtime. This part is fairly easy. Create a class inheriting from MarkupExtension, add a constructor that accepts the text key as argument, store it in a private field, and let its ProvideValue method return a translation text for the stored key.
My real problem is this: How can I make my markup extension accept a counting value in such a way that it's data-bound and the translation text will update accordingly when the count value changes?
It should be used like this:
<TextBlock Text="{t:Translate 'import files', {Binding FileCount}}"/>
Whenever the binding value of FileCount changes, the TextBlock must receive a new text value to reflect the change and still provide a good wording.
I've found a similar-looking solution over there: http://blogs.microsoft.co.il/blogs/tomershamam/archive/2007/10/30/wpf-localization-on-the-fly-language-selection.aspx But as hard as I try to follow it, I can't understand what it does or why it even works. Everything seems to happen inside of WPF, the provided code only pushes it in the right direction but it's unclear how. I can't get my adaption of it to do anything useful.
I'm not sure whether it could be useful to let the translation language change at runtime. I think I'd need another level of bindings for that. To keep complexity low, I would not seek to do that until the basic version works.
At the moment there's no code I could show you. It's simply in a terrible state and the only thing it does is throwing exceptions, or not translating anything. Any simple examples are very welcome (if such thing exists in this case).
Nevermind, I finally found out how the referenced code works and could come up with a solution. Here's just a short explanation for the record.
<TextBlock Text="{t:Translate 'import files', {Binding FileCount}}"/>
This requires a class TranslateExtension, inherited from MarkupExtension, with a constructor accepting two parameters, one String and one Binding. Store both values in the instance. The classes' ProvideValue method then uses the binding it gets, adds a custom converter instance to it and returns the result from binding.ProvideValue, which is a BindingExpression instance IIRC.
public class TranslateExtension : MarkupExtension
{
public TranslateExtension(string key, Binding countBinding)
{
// Save arguments to properties
}
public override object ProvideValue(IServiceProvider serviceProvider)
{
countBinding.Converter = new TranslateConverter(key);
return countBinding.ProvideValue(serviceProvider);
}
}
The converter, say of class TranslateConverter, has a constructor that accepts one parameter, a String. This is my key argument from the TranslateExtension above. It remembers it for later.
Whenever the Count value changes (it comes through the binding), WPF will request its value anew. It seems to walk from the source of the binding, through the converter, to the surface where it's displayed. By using a converter, we don't have to worry about the binding at all, because the converter gets the binding's current value as a method argument and is expected to return something else. Counting value (int) in, translated text (string) out. This is my code.
So it's the converter's task to adapt the number to a formulated text. It uses the stored text key for that. So what happens is basically a kinda backwards data flow. Instead of the text key being the main information and the count value being added to it, we need to treat the count value as the primary information and just use the text key as a side parameter to make it whole. This isn't exactly straightforward, but the binding needs to be the primary trigger. Since the key won't change, it can be stored for good in the instance of the converter. And every occurence of a translated text gets its own copy of the converter, each with an individual key programmed in.
This is what the converter could look like:
class TranslateConverter : IValueConverter
{
private string key;
public TranslateConverter(string key)
{
this.key = key;
}
public object Convert(object value, ...)
{
return Translator.Translate(key, (int) value);
}
}
That's the magic. Add the error handling and more features to get the solution.
I have a wpf datagrid that I want to sort programatically as if the user had clicked on the header. After some searching I found reference to using this:
datagrid_selected.Items.SortDescriptions(2).Direction = ComponentModel.ListSortDirection.Ascending
Looks like it would work. Intellisense says Direction is a getter and setter, but when I try to assign it to something I get the "Expression is a value and therefor cannot be the target of an assignment" error. By nature as a setter I should be able to assign this to a value, right? Any idea what's going wrong?
It appears as if SortDescriptions are boxed values.
Instead, try the following.
var sortDescription = grid.Items.SortDescriptions[0];
sortDescription.Direction = System.ComponentModel.ListSortDirection.Ascending;
grid.Items.SortDescriptions[0] = sortDescription;
This drives me crazy:
i'm using a datagridview (bound to a dataset) and textboxes also bound to the dataset (which means that everything typed into the textboxes is reflected in the datagridview). The datagridview is actually used only to show up the values (user is NOT able to edit anything in the cells).
So: when the user pushes the add new record button (automatically created by visual studio using binding navigator etc. ) i would like to programmatically select this new line (remember: user has not the ability to select with the mouse) and insert some values.
I tried to use the
DefaultValuesNeeded
event, but this is firing only if the user selects the row with the asterisk indicator (what the user is not allowed to do).
How can i simulate that behavior? Should i take another approach?
Thanks in advance!!
Was searching for alternatives to how I currently do this and just wanted to let you know about a couple ways I know of. Both of these will set defaults when using the * (new row) or using a BindingNavigator.
private void CityBindingSource_AddingNew(object sender,
AddingNewEventArgs e)
{
// Simply set the default value to the next viable ID,
// will automatically set the value when needed.
locationDataSet.CITY.CITY_IDColumn.DefaultValue =
CityTableAdapter.GetNewID(); // ++maxID;
}
Or
private void CityDataGridView_DefaultValuesNeeded(object sender,
DataGridViewRowEventArgs e)
{
// Gets called when datagridview's */NewRow is entered.
e.Row.Cells[0].Value = CityTableAdapter.GetNewID(); // ++maxID;
}
private void bindingNavigatorAddNewItem_Click(object sender,
EventArgs e)
{
// BindingNavigator button's AddNewItem automatic tie-
// in to bindingSource's AddNew() is removed.
// This sets the current cell to the NewRow's cell to trigger
// DefaultValuesNeeded event.
CityDataGridView.CurrentCell =
CityDataGridView.Rows[CityDataGridView.NewRowIndex].Cells[1];
}
I was really hoping to use this:
private void CityBindingSource_AddingNew(object sender,
AddingNewEventArgs e)
{
// Cast your strongly-typed
// bindingsource List to a DataView and add a new DataRowView
DataRowView rowView =
((DataView)CityBindingSource.List).AddNew();
var newRow = (LocationDTSDataSet.CITYRow)rowView.Row;
newRow.CITY_ID = CityTableAdapter.GetNewID();
newRow.CMMT_TXT = "Whatever defaults I want";
e.NewObject = rowView;
}
But when adding using the BindingNavigator or any code based bindingSource.AddNew() it results in just a blank row. Hopefully someone finds a better way, but this is working for me so far.
Revised:
How about the Datatable's TableNewRow event, then? If that gets fired when the BindingNavigator creates a new row, then that's an opportunity to populate the object.