What is the best way to remember Text/Value of a control after it is enabled again?
In my special case I have a checkbox to enable/disable a NumericSpinBox.
When checkbox is switched to Checked=false: spinbox is disabled and the last value (e.g. 10) should be remembered and the text should be cleared.
When checkbox is switched to Checked=true: spinbox is enabled again and the remembered value (e.g. 10) is reassigned.
Ok, I could store the value in an extra field of my form or container control. But if there are several controls with remembering values the additional fields are too much overhead (in terms of readability) for so small feature IMO.
So I hope you have better solutions.
You can store value in the Tag property of the numericbox or checkbox
Define a Type that represent the fields that you want and create an object of that type that hold all the state of your UI element. Set the value manually on enable or use binding
Related
I am not sure combobox would be the best vehicle for tackling this problem, but visually it is appealing.
Consider such data as angle -- I could enter its value in radians (single editbox) or in form of degree, minute, second, millisecond (4 editboxes) -- there are other representations, but those two will suffice here. For now I have combobox with mode entries "radians", "DMS" changing mode shows/hides appropriate control.
This approach has two flaws -- it takes a bit more space (for extra combobox with modes), and since each control is different is size everything on right of it moves.
So I am thinking about more direct approach, instead selecting mode, which in turns switches visibility of given control, would it be possible to put each control inside combobox, and combobox would then select that control. The target data would be exactly the same for each row (angle), but each row would have different control, because each row would mean different representation.
Is doable with combobox or am I banging at the wrong door? If combobox is suitable for this task, how to do it?
I was so focused on data binding at the combobox level that I didn't notice that the solution uses the basics of combobox.
So first, for the moment forget about combobox binding to anything -- simply per each row define ComboBoxItem and put any control you like. In effect you will get multiple controls for the same data.
At this point the only missing part is selecting the mode. Since I no longer rely on manually switching visibility of the controls (combobox does it automatically) then I can bind to SelectedIndex and convert it only fly back and forth to mode.
Please note combobox is not bound per se to the actual data (angle in this case).
How can I get my CheckBoxList to have three possible states ? More precisely, is there a way to have three possible states for each checkbox : checked, unchecked, undefined (in most GUIs this is represented as a full square).
Alternatively, do you recommend another control that would meet these needs ?
UPDATE : Ok, given that HTML does not support tri-state checkboxes, I'm looking for a way to 'CSS' (color fill, highlight, etc...) the checkboxes of the items that are in that 'undefined' state from my server point of view.
Not all GUIs represent undefined as a full square. That's why it's going to be clearer to use one of the following:
1. Radio boxes
2. Dropdown
3. ListBox
Any asp.net control you use will ultimately need to be rendered as an html checkbox, which can only be checked or unchecked. You could use a data- attribute to keep track of extra state behind the scenes, but that wouldn't be reflected in the UI.
I suppose you could also implement a client-side solution using JavaScript and CSS as well.
You could just extend or derive from the CheckBoxList and create your own custom control from it.
Here is an example of this.
Custom CheckBoxList
I have decided to use CheckBoxList anyway, since I need two states accessible by the user, and a third one not accessible by the user but to display inconsistencies.
The way I have solved this is through Javascript + CSS. Some bits of ideas here: http://css-tricks.com/indeterminate-checkboxes/
I'm working a WPF application which has a number of groupboxes, each containing 3-4 controls a piece. Each of these groupboxes contains a reset button.
Instead of explicitly writing a line for each item the groupbox reset buton should reset is there a way to have the reset button only reset all items for the groupbox it's contained upon?
When researching this issue I found the following post which seems relevant but I'm unsure how to extend Nathan's answer to do this: What is the best way to clear all controls on a form C#?
You can use this question as an source of methods you need.
First of all you need to find groupbox that contains button. To do that use sender argument form click event it is reference to button that was clicked and call FindVisualParent method from one of answers in that question. This will give you groupbox.
Then Find all ui elements by FindVisualChildren<DependencyObject> method. This will give you super set of controls that are to be cleared.
Then it is just a loop over this as in question that you referenced. Note that that question was intended for winforms not wpf so you will have to revise the controldefaults dictionary which handles grouping controls ~(Panel GroupBox) which is not needed here (and would not work in wpf).
You might add a TAG to each control telling which property is beeing edited in the control, and then on reset press, you travel up the button to find containing GroupBox, then down to find all controls contained in this GroupBox, and then you find, with the TAGs, the name of the properties that needs reset. You then reset the properties using Reflexion.
Maybe an issue is that the default value might not be obvious. But you could store the default values for all your bindings in a static object, and copy the value of the property for this reset object into the current status object.
Rq : you could also use reflexion to get the bindings for all control of current GroupBox, and then get the bounded properties from the binding, so no need for a TAG. BUT if a control has several bindings, you won't know which one to reset. In my case, controls within GroupBoxes have also a color binding to indicate wether they have default value (green) or non-default (red), hence the need for a TAG. (BUT the color indicator are read-only so reflexion could, in fact, also be used with a little more use of Reflexion... was just too lazy to change a working logic when i saw that :-) )
I don't know about your bindings so obviously i cannot tell what's best, i hope this thoughs can help.
In WinForm, I have a combobox with DropDownStyle set to DropDownList (so can't enter a Text). In the properties window, there is the Items property which is a string collection. I enter all my values.
But now, I would like to set one of these value by default (instead to have the empty entry at run-time). I know how to do this via coding, but I am pretty sure (damn memory) that it was possible to set one of the value in the string collection as default by adding a special symbole in front of the line.
Anybody know that symbole? Or my memory is playing me trick and it is not possible to do it via the designer?
Doesn't look like it can be done when using a DropDownList. From here it is suggested that you can set the text property to the default value you want, but this will only works in a DropDown rather than DropDownList style.
I'm sorry but that is not possible within the Designer only, since the Text property is used for this feature and that property is ignored/cleared when the using a DropDownList.
If you don't mind having your data values outside of the Designer, you could probably use DataBinding to accomplish this since the DisplayMember and ValueMember properties of ComboBox can be used in the Designer and would set the display value. I don't normally use DataBinding so unfortunately I cannot provide code examples - perhaps another user can chime in?
I looked at http://msdn.microsoft.com/en-us/library/7tas5c80.aspx for reference and it makes sense as far as editable column goes.
The question is how do I host a "view only" custom control in a DataGridView (WinForm and C#)?
Derive from DataGridViewCell and override the Paint methods.
Another easy way would be to make that column one of the "DataKeyNames" columns of the grid. Any field that is considered a "Key" is by default disabled from a user editing it. However, if you deal with object analysis on "clicked" on records for editing, or other, the array of returned keys will be in the same sequence as they are listed in the DataKeyNames property. So, even though you may be ignoring the actual value as a "Key", it can act to disable it.
HTH