Wpf textblock text binding not updating

The third and last Text Box uses the Property Changed value, which means that the source value will be updated each time the bound property changes, which it does in this case as soon as the text changes.Try running the example on your own machine and see how the three textboxes act completely different: The first value doesn't update before you click the button, the second value isn't updated until you leave the Text Box, while the third value updates automatically on each keystroke, text change etc.

As of writing, all properties except for the Text property, is updated as soon as the property changes (Property Changed), while the Text property is updated when focus on the destination element is lost (Lost Focus).

Default is, obviously, the default value of the Update Source Trigger.

In the following example, the highlighted lines of code show that the As a result, the Text Block shows the same text (because the source changes) as the user enters text into the Text Box, as illustrated by the following screenshot of the sample: If you have a dialog or a user-editable form and you want to defer source updates until the user is finished editing the fields and clicks "OK", you can set the Update Source Trigger value of your bindings to Explicit, as in the following example: Note You can use the same technique for properties of other controls, but keep in mind that most other properties have a default Update Source Trigger value of Property Changed.

For more information, see the Update Source Trigger property page.

The Update Source Trigger property of a binding controls how and when a changed value is sent back to the source.

However, since WPF is pretty good at controlling this for you, the default value should suffice for most cases, where you will get the best mix of a constantly updated UI and good performance.

As you can see, each of the three textboxes now uses a different Update Source Trigger.

The first one is set to Explicit, which basically means that the source won't be updated unless you manually do it.

And the problem in reality is in all your Text Box’s’ binding: Your bindings are so simple format, only binding to the property (in the above case ‘Path’), The binding in the above case has all other properties set to default values except the one set explicitly ‘Path’. Update Source Trigger It’s set to Default by default.

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