Set the focus on a textbox in xaml wpf

问题:

Despite some posts on this forum and others i cannot find something that tells me how to set the focus on a TextBox.

I have a userControl with many labels and textBoxes. When the form is loaded I want the a particular textBox to have the focus.

I have set the tabIndex but that didn't seem to work.

Any suggestions?

回答1:

You can use the FocusManager.FocusedElement attached property for this purpose. Here's a piece of code that set the focus to TxtB by default.

<StackPanel Orientation="Vertical" FocusManager.FocusedElement="{Binding ElementName=TxtB}">
    <TextBox x:Name="TxtA" Text="A" />
    <TextBox x:Name="TxtB" Text="B" />
</StackPanel>

You can also use TxtB.Focus() in your code-behind if you don't want to do this in XAML.

回答2:

You can apply this property directly on the TextBox :

<TextBox Text="{Binding MyText}" FocusManager.FocusedElement="{Binding RelativeSource={RelativeSource Self}}"/>

回答3:

I am new to using WPF and reading through the above examples I had a similar experience trying set the focus to a textbox using the xaml code examples given, i.e. all the examples above didn't work.

What I found was I had to place the FocusManager.FocusElement in the page element. I assume this would probably work as well if you used a Window as the parent element. Anyway, here is the code that worked for me.

 <Page x:Class="NameOfYourClass"
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
  xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
  mc:Ignorable="d"
  Title="Title" 
  Height="720"
  Width="915"
  Background="white"
  Loaded="pgLoaded"
  FocusManager.FocusedElement="{Binding ElementName=NameOfYourTextBox}">

  <!-- Create child elements here. -->

  </Page>

回答4:

bind the element you want to point the focus in as

FocusManager.FocusedElement= "{Binding ElementName= Comobox1}"

in grid or groupbox etc

回答5:

FocusManager was not in intellisense and this confused me a bit. I just typed the entire attribute and it worked.

FocusManager.FocusedElement="{Binding ElementName=MyTextBox}"

---

Microsoft Visual Studio Enterprise 2015 version 14.0.23107.0/C#/WPF

回答6:

For completeness, there is also a way to handle this from code behind (e.g. in the case of controls that, for whatever reason, are created dynamically and don't exist in XAML). Attach a handler to the window's Loaded event and then use the ".Focus()" method of the control you want. Bare-bones example below.

public class MyWindow
{
    private VisualCollection controls;
    private TextBox textBox;

    // constructor
    public MyWindow()
    {
        controls = new VisualCollection(this);
        textBox = new TextBox();
        controls.Add(textBox);

        Loaded += window_Loaded;
    }

    private void window_Loaded(object sender, RoutedEventArgs e)
    {
        textBox.Focus();
    }
}

回答7:

In my case, the provided answers did not work. Somewhere in the code after the InitializeComponent();

I had to add

MyTextBox.Focus(); and it works.