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Created attachment 8371 [details]
1. Open attached project
2. Build and Deploy to Simulator
3. Enter the "Buy Pears" item
4. Activate Switch
5. Navigate to and Enter Buy Pears
6. Enter some text
7. Disable the switch
The edited/entered control should become disabled and dark grey
It stays white
I have checked this issue as per steps defined in bug description, And I am getting same behavior defined in bug description.
Output Log: https://gist.github.com/Parmendrak/35e64405c8b2beaf3b9b
=== Xamarin Studio ===
Version 5.5 (build 227)
Installation UUID: 1a096c6f-0678-402e-89b2-a2c10f7e80e4
Mono 3.10.0 ((detached/47db868)
GTK+ 2.24.23 (Raleigh theme)
Package version: 310000019
=== Apple Developer Tools ===
Xcode 6.0.1 (6528)
=== Xamarin.iOS ===
Version: 126.96.36.199 (Business Edition)
Build date: 2014-10-03 00:25:37-0400
=== Xamarin.Android ===
Version: 4.18.0 (Business Edition)
Android SDK: /Users/360_macmini/Desktop/android-sdk-macosx
Supported Android versions:
2.1 (API level 7)
2.2 (API level 8)
2.3 (API level 10)
3.1 (API level 12)
3.2 (API level 13)
4.0 (API level 14)
4.0.3 (API level 15)
4.1 (API level 16)
4.2 (API level 17)
4.3 (API level 18)
4.4 (API level 19)
4.4.87 (API level 20)
Java SDK: /usr
java version "1.6.0_65"
Java(TM) SE Runtime Environment (build 1.6.0_65-b14-462-11M4609)
Java HotSpot(TM) 64-Bit Server VM (build 20.65-b04-462, mixed mode)
=== Xamarin.Mac ===
Version: 188.8.131.52 (Business Edition)
=== Build Information ===
Release ID: 505000227
Git revision: 7b721eeec7a2fa4c4f4de0ecd2aed4dc25edac95
Build date: 2014-10-02 15:53:38-04
Xamarin addins: 99ed56b428b31eba1efaace4d82188d6f334e6ca
=== Operating System ===
Mac OS X 10.9.4
Darwin ShrutiMac.local 13.3.0 Darwin Kernel Version 13.3.0
Tue Jun 3 21:27:35 PDT 2014
The original description is missing some important context from the Desk case.
The reason this behavior is suspected to be a bug is that all of the items have the same binding for the `BackgroundColorProperty`. Selecting and editing an item in the list is somehow disabling the binding on that item.
- When the user first navigates into the "Buy Pears" editing view, the background color of the "Buy Pears" item responds to the state of the switch control.
- After the user has changed the text of the "Buy Pears" item to "Buy Apples", the background color of the "Buy Apples" item does _not_ respond to the state of the switch control.
## Additional information
I'll update this bug again in a little bit with:
- Confirmation that the problem occurs on the latest Xamarin.Forms version.
- A note about whether the problem also occurs on Android and Windows Phone. In general, I suspect it would be helpful to specify the list of affected platforms on all Xamarin.Forms bugs.
Update: I think this might be an intentional behavior of the Xamarin.Forms binding machinery and not a bug.
## Workaround (or maybe really the correct fix)
Change the following line in `TodoItemPage.OnControlLoseFocus()`:
> ((Entry)sender).BackgroundColor = Xamarin.Forms.Color.White;
> ((Entry)sender).SetBinding(StackLayout.BackgroundColorProperty, new Binding("SelectedBackgroundColor", BindingMode.OneWay));
## Further explanation
Explicitly setting  the `BackgroundColor` property in `TodoItemPage.OnControlReceivedFocus()` apparently un-sets the binding. Re-setting the binding allows it to work again as normal.
>  ((Entry)currentControl).BackgroundColor = Xamarin.Forms.Color.Lime;
## Version information
Tested on iPhone 4s (iOS 7.1.2), iPhone simulator (iOS 8.0), Android device (Android 4.1.2)
Xamarin 184.108.40.206 (ff146f5240189a2ec6d3c6f75cf3967f79c79a18)
Xamarin.Android 220.127.116.11 (3b7ef0a796e8744972c48034403a6e7cb7ec189e)
Xamarin.iOS 18.104.22.168 (65b2f3a0f52f365b90ac952f0ec2e40fa0b510d4)
Created attachment 8394 [details]
Simpler test case
This is probably unnecessary at this point, but here's an even simpler test case that also includes sub-projects for all 3 platforms: iOS, Android, and Windows Phone.
This test case explicitly sets the `BackgroundColor` property on `entryElement2` directly during initialization rather than in the `Focused` and `Unfocused` event handlers.
## Steps to reproduce
1. Run the app on any iOS, Android, or Windows Phone device, emulator, or simulator.
2. Tap the `Switch` element.
The background of the second `Entry` element does _not_ change to gray when the switch moves to the "off" position.
## Workaround / fix
Uncomment the line in `App.GetMainPage()` after the explicit property set that re-sets the binding:
> entryElement2.SetBinding(StackLayout.BackgroundColorProperty, new Binding("SelectedBackgroundColor", BindingMode.OneWay));
Actually this is how Bindings are supposed to work. If you want to set the property without unsetting your binding, you need to update your ViewModel.
Note there was a bug where sometimes the bindings would get unset when the Entry would update as the user types. This has been resolved.
For my scenario, I have some Entry fields that will have bindings for the background color and some that will not have this binding. For all Entry fields, I need to change the background color when the control receives focus. I am performing this logic in a base class with several different views derived from this. Is there a way to tell if a control has bindings set for the background color property and then save the binding information off before changing the color? Then reset the binding information when the control loses focus?
I wanted to follow up on my question - is there a way to determine if there is a binding defined for a given property, save that binding information off, and then reassign it?