How to bind NSAttributedString to UITextView

Question

we are using MVVMCross and we are having trouble binding an NSAttributedString to a UITextView. It's weird because the same code works without using a BindingSet and also using Bindig for Text property instead of AttributedText

As said, this line of code is not binding, the TextView just shows the default text:

set.Bind (TxtActivityText).For(txt => txt.AttributedText).To (vm => vm.Activity).WithConversion("ActivitySpanMessage");

... and outputs the following warning: "MvxBind:Warning: 6.06 Failed to create target binding for binding AttributedText for Activity"

While with this line is working fine:

set.Bind (TxtActivityText).For(txt => txt.Text).To (vm => vm.Activity).WithConversion("ActivitySpanMessage"); // Works fine also binding to the default property

And finally, without using bindings it works fine too:

TxtActivityText.AttributedText = SpanMessageHelper.ConvertToAttributedString(ViewModel.Activity, null, null, null); // This function is the same I call in the ActivitySpanMessageConverter

Any ideas? May this be a bug?

Is there any debug information in trace? Is there any more info you can provide in the question - e.g. some code values that are used? it "may be a bug"(TM) but others have seen Attributed Text binding working fine - eg. stackoverflow.com/questions/17934294/… and github.com/MvvmCross/MvvmCross/issues/791 — Stuart
Yes, it says MvxBind:Warning: 6.06 Failed to create target binding for binding AttributedText for Activity. It's weird because it's a pretty simple casa: simple XIB done with xCode6 with some other controls working fine. Tomorrow I'll try if its a problem with the simulator — Jordi Corominas
Please edit the question to include the relevant trace and information - it's easier to read in the question than it is in the comments. Thanks. — Stuart

chkimes chkimes · Accepted Answer · 2015-03-30T18:56:11

This is probably because the Xamarin linker is not including UITextView.AttributedText since it is only used in an expression. See this post for more info: MvvmCross Failed to create target binding for EditingDidBegin on iPhone

You can fix this by going to LinkerPleaseInclude.cs and changing your UITextView include method:

public void Include(UITextView textView)
{
    textView.Text = textView.Text + "";
    textView.Changed += (sender, args) => { textView.Text = ""; };

    // Add this line here
    textView.AttributedText = new NSAttributedString();
}

How to bind NSAttributedString to UITextView

1 Answers