C# Maui暂时还没有TextBox,因为这个可以通过xaml样式实现,但是为了长期使用,自己写一个TextBox。
定义一个TextEventArgs
public class TextEventArgs : EventArgs
{
public string Text{ get; set; }
public TextEventArgs(string text)
{
Text = text;
}
}
PropertyManager和之前的例子一样,这里就不重复了。除非更新了新功能。
我的MauiProgram.cs中添加了自定义字体,这个在第一个MAUI 配置中说了,以后也不再重复了。自己去https://www.iconfont.cn/注册账号,添加自己喜欢的字体icon,然后下载下来覆盖项目中的IconFont.ttf
fonts.AddFont("IconFont.ttf", "IconFont");
TextBox继承Border,以后所有自定义控件都继承于Border,不要用Frame了,因为这个在将来的未来会被淘汰。现在Border可以实现所有功能。
public class TextBox : Border
{
public static readonly BindableProperty TextProperty = BindableProperty.Create(
nameof(Text), typeof(string), typeof(TextBox), null,
BindingMode.TwoWay, propertyChanged: OnTextChanged);
public static readonly BindableProperty IsPasswordProperty = BindableProperty.Create(
nameof(IsPassword), typeof(bool), typeof(TextBox), false);
public static readonly BindableProperty IsMultilineProperty = BindableProperty.Create(
nameof(IsMultiline), typeof(bool), typeof(TextBox), false);
public static readonly BindableProperty PlaceholderProperty = BindableProperty.Create(
nameof(Placeholder), typeof(string), typeof(TextBox), null);
public static readonly BindableProperty TextColorProperty = BindableProperty.Create(
nameof(TextColor), typeof(Color), typeof(TextBox), Colors.Black);
public static readonly BindableProperty TextSizeProperty = BindableProperty.Create(
nameof(TextSize), typeof(double), typeof(TextBox), 15d);
public static readonly BindableProperty IsReadOnlyProperty = BindableProperty.Create(
nameof(IsReadOnly), typeof(bool), typeof(TextBox), false,
propertyChanged: OnIsReadOnlyChanged);
public static readonly BindableProperty CharacterSpacingProperty = BindableProperty.Create(
nameof(CharacterSpacing), typeof(double), typeof(TextBox), 0d);
public static readonly BindableProperty CornerRadiusProperty =
BindableProperty.Create(nameof(CornerRadius), typeof(double), typeof(TextBox), 0d,
propertyChanged: PropertyManager.CornerRadiusProperty);
public static readonly BindableProperty IconTextProperty =
BindableProperty.Create(nameof(IconText), typeof(string), typeof(TextBox), null);
public static readonly BindableProperty IconTextColorProperty =
BindableProperty.Create(nameof(IconTextColor), typeof(Color), typeof(TextBox), Colors.Gray);
public static readonly BindableProperty IconTextFontSizeProperty =
BindableProperty.Create(nameof(IconTextFontSize), typeof(double), typeof(TextBox), 22d);
public static readonly BindableProperty IconFontFamilyProperty =
BindableProperty.Create(nameof(IconFontFamily), typeof(string), typeof(TextBox), "IconFont");
public event EventHandler<TextEventArgs>? ReturnPressed, EditingFinished;
public string Text
{
get => (string)GetValue(TextProperty);
set => SetValue(TextProperty, value);
}
public bool IsPassword
{
get => (bool)GetValue(IsPasswordProperty);
set => SetValue(IsPasswordProperty, value);
}
public bool IsMultiline
{
get => (bool)GetValue(IsMultilineProperty);
set => SetValue(IsMultilineProperty, value);
}
public string Placeholder
{
get => (string)GetValue(PlaceholderProperty);
set => SetValue(PlaceholderProperty, value);
}
public Color TextColor
{
get => (Color)GetValue(TextColorProperty);
set => SetValue(TextColorProperty, value);
}
public double TextSize
{
get => (double)GetValue(TextSizeProperty);
set => SetValue(TextSizeProperty, value);
}
public bool IsReadOnly
{
get => (bool)GetValue(IsReadOnlyProperty);
set => SetValue(IsReadOnlyProperty, value);
}
public double CharacterSpacing
{
get => (double)GetValue(CharacterSpacingProperty);
set => SetValue(CharacterSpacingProperty, value);
}
public double CornerRadius
{
get => (double)GetValue(CornerRadiusProperty);
set => SetValue(CornerRadiusProperty, value);
}
public string IconText
{
get => (string)GetValue(IconTextProperty);
set => SetValue(IconTextProperty, value);
}
public Color IconTextColor
{
get => (Color)GetValue(IconTextColorProperty);
set => SetValue(IconTextColorProperty, value);
}
public double IconTextFontSize
{
get => (double)GetValue(IconTextFontSizeProperty);
set => SetValue(IconTextFontSizeProperty, value);
}
public string IconFontFamily
{
get => (string)GetValue(IconFontFamilyProperty);
set => SetValue(IconFontFamilyProperty, value);
}
private static void OnTextChanged(BindableObject bindable, object oldValue, object newValue)
{
var tb = (TextBox)bindable;
var newText = newValue as string ?? string.Empty;
var oldText = oldValue as string ?? string.Empty;
if (newText.Length > oldText.Length && tb.IsMultiline)
{
var addText = newText.Substring(oldText.Length);
if (addText.Contains('\r') || addText.Contains('\n'))
{
//如果是回车换行,则触发ReturnPressed事件,安全派发到UI线程
tb.Dispatcher.Dispatch(() => tb.ReturnPressed?.Invoke(tb, new TextEventArgs(newText)));
}
}
}
//动态更新IsReadOnly属性
private static void OnIsReadOnlyChanged(BindableObject bindable, object oldValue, object newValue)
{
var tb = (TextBox)bindable;
if (tb.grid.Children.Count == 0)
return;
if (tb.grid.Children[0] is InputView view)
{
view.IsReadOnly = (bool)newValue;
view.Background = (bool)newValue ? Colors.WhiteSmoke : Colors.Transparent;
}
}
private Grid grid;
public TextBox()
{
grid = new Grid()
{
ColumnDefinitions = new ColumnDefinitionCollection
{
new ColumnDefinition { Width = GridLength.Star },
new ColumnDefinition { Width = GridLength.Auto }
},
};
// 设置布局
this.Content = grid;
this.StrokeThickness = 1;
this.Stroke = Colors.LightGray;
this.StrokeShape = new RoundRectangle() { CornerRadius = CornerRadius };
this.Padding = new Thickness(0);
//重载OnHandlerChanged中也可以初始化,构造函数会先于属性设置执行
//Dispatcher.Dispatch(Init)也可以初始化
this.Loaded += Init;
}
private void Init(object? sender, EventArgs e)
{
//凡是设置了propertyChanged的属性,都需要在这里手动初始化,因为Dispatcher.Dispatch/Loaded会在propertyChanged之后执行
InputView edit = IsMultiline ?
new Editor()
{
Margin = new Thickness(0),
AutoSize = EditorAutoSizeOption.TextChanges,
VerticalTextAlignment = TextAlignment.Start,
IsReadOnly = IsReadOnly,
Background = IsReadOnly ? Colors.WhiteSmoke : Colors.Transparent,
} :
new Entry()
{
Margin = new Thickness(0),
VerticalTextAlignment = TextAlignment.Start,
IsReadOnly = IsReadOnly,
Background = IsReadOnly ? Colors.WhiteSmoke : Colors.Transparent,
};
grid.Children.Add(edit);
edit.SetBinding(InputView.TextProperty, new Binding(nameof(Text), mode: BindingMode.TwoWay, source: this));
edit.SetBinding(InputView.PlaceholderProperty, new Binding(nameof(Placeholder), mode: BindingMode.TwoWay, source: this));
edit.SetBinding(InputView.TextColorProperty, new Binding(nameof(TextColor), mode: BindingMode.TwoWay, source: this));
edit.SetBinding(InputView.FontSizeProperty, new Binding(nameof(TextSize), mode: BindingMode.TwoWay, source: this));
edit.SetBinding(InputView.CharacterSpacingProperty, new Binding(nameof(CharacterSpacing), mode: BindingMode.TwoWay, source: this));
if (edit is Entry entry)
{
edit.SetBinding(Entry.IsPasswordProperty, new Binding(nameof(IsPassword), mode: BindingMode.TwoWay, source: this));
entry.Completed += (s, e) =>
{
ReturnPressed?.Invoke(this, new TextEventArgs(edit.Text));
edit.Unfocus();
};
}
edit.Unfocused += (s, e) =>
{
EditingFinished?.Invoke(this, new TextEventArgs(edit.Text));
};
if (IsPassword)
{
Label icon = new Label()
{
Text = IconText,
FontFamily = IconFontFamily,
FontSize = IconTextFontSize,
TextColor = IconTextColor,
VerticalTextAlignment = TextAlignment.Center,
Margin = new Thickness(10, 0),
};
grid.Children.Add(icon);
Grid.SetColumn(icon, 1);
icon.SetBinding(Label.TextProperty, new Binding(nameof(IconText), mode: BindingMode.TwoWay, source: this));
icon.SetBinding(Label.TextColorProperty, new Binding(nameof(IconTextColor), mode: BindingMode.TwoWay, source: this));
icon.SetBinding(Label.FontSizeProperty, new Binding(nameof(IconTextFontSize), mode: BindingMode.TwoWay, source: this));
icon.SetBinding(Label.FontFamilyProperty, new Binding(nameof(IconFontFamily), mode: BindingMode.TwoWay, source: this));
TapGestureRecognizer tapGesture = new TapGestureRecognizer();
tapGesture.Tapped += OnTapped;
icon.GestureRecognizers.Add(tapGesture);
}
}
private void OnTapped(object? sender, TappedEventArgs e)
{
Grid? grid = (sender as Label)?.Parent as Grid;
if (grid == null)
return;
if (grid.Children[0] is Entry entry)
{
entry.IsPassword = !entry.IsPassword;
}
}
}
TextBox.xaml (前面的例子已经说明了如何把自定义控件,加到默认命名空间,以后也不再重复了)
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="MauiViews.MauiDemos.Book._03.TextBox"
Title="TextBox" HeightRequest="400" WidthRequest="300">
<Grid RowDefinitions="auto,auto,auto, *">
<TextBox Placeholder="单行输入-只读" CornerRadius="15" IsReadOnly="True"/>
<TextBox Grid.Row="1" Placeholder="单行输入" ReturnPressed="TextBox_ReturnPressed" CornerRadius="15"/>
<TextBox Grid.Row="2" Placeholder="密码输入" IsPassword="True" ReturnPressed="TextBox_ReturnPressed"
IconText=""/>
<TextBox Grid.Row="3" Placeholder="多行输入" IsMultiline="True" ReturnPressed="TextBox_ReturnPressed"/>
</Grid>
</ContentPage>
对应的cs代码
using Shares.Utility;
using System.Diagnostics;
namespace MauiViews.MauiDemos.Book._03;
public partial class TextBox : ContentPage
{
public TextBox()
{
InitializeComponent();
}
private void TextBox_ReturnPressed(object? sender, TextEventArgs e)
{
Trace.WriteLine($"TextBox_ReturnPressed: {e.Text}");
}
}
运行效果