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;

没有工作：（

Answer 1

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);
        }
    }
}

并向顶部添加：

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

Answer 2

如其他答案中所述，如果您使用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，否则它将不起作用：

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

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 4

UWP自定义条目渲染器可能是......

using System.ComponentModel;

using Xamarin.Forms;
using Xamarin.Forms.Platform.UWP;

[assembly: ExportRenderer(typeof(Entry), typeof(myApp.UWP.ExtendedEntryRenderer))]
namespace myApp.UWP
{
    public class ExtendedEntryRenderer : EntryRenderer
    {
        protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
        {
            base.OnElementPropertyChanged(sender, e);

            if (e.PropertyName == nameof(Entry.IsFocused)
                && Control != null && Control.FocusState != Windows.UI.Xaml.FocusState.Unfocused)
                Control.SelectAll();
        }
    }
}

Answer 5

在我的情况下，要做出@SAIJAN KP的答案，我制作了Focused处理程序async，并等待了一段时间以等待光标出现在Entry上：

    private async void Entry_Focused(object sender, FocusEventArgs e)
    {
        await Task.Delay(100);
        entryTest.CursorPosition = x;
        entryTest.SelectionLength = y;
    }

XAML

<Entry x:Name="entryTest" Text="155134343" Focused="Entry_Focused"  />

自动选择焦点Xamarin上的所有文本

5 个答案: