自动选择焦点Xamarin上的所有文本

Question

如何在Entry,Editor,Label中自动选择焦点上的所有文本？使用跨平台.

Quantity.IsFocused = true; 

没工作:(

Answer 1

1.添加焦点事件.Cs

protected  void Txt_Focussed(object sender, FocusEventArgs e)
{
    txt.CursorPosition = 0;
    txt.SelectionLength = txt.Text.Length;
}

设置焦点

protected override void OnAppearing()
{
    base.OnAppearing();
    txt.Focus();
}

XAML 代码

<Entry x:Name="txt" Text="155134343" Focused="Txt_Focussed" />

Answer 2

如其他答案中所述，如果您使用的是 Xamarin Forms 4.2+，则可以使用 CursorPosition 和 SelectionLength 属性。但是，您需要确保在主线程上调用它，否则它将无法工作：

XAML

<Entry x:Name="MyEntry" Focused="MyEntry_Focused"  />

C＃

private void MyEntry_Focused(object sender, FocusEventArgs e)
{
    Dispatcher.BeginInvokeOnMainThread(() =>
    {
        MyEntry.CursorPosition = 0;
        MyEntry.SelectionLength = MyEntry.Text != null ? MyEntry.Text.Length : 0
    });
}

Answer 3

在MainActivity中添加

public class MyEntryRenderer : EntryRenderer
{
    protected override void OnElementChanged (ElementChangedEventArgs<Entry> e)
    {
        base.OnElementChanged (e);
        if (e.OldElement == null) {
            var nativeEditText = (global::Android.Widget.EditText)Control;
            nativeEditText.SetSelectAllOnFocus (true);
        }
    }
}

并添加到顶部:

[assembly: ExportRenderer (typeof (Entry), typeof (MyEntryRenderer))]