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<Window x:Class="WpfApp1.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:local="clr-namespace:WpfApp1" mc:Ignorable="d" Title="MainWindow" Height="450" Width="800"> <StackPanel Orientation="Horizontal"> <TextBox Text="{Binding InTexts, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Width="120" VerticalAlignment="Top"/> <TextBlock Text="{Binding Comments}" Foreground="Red" /> </StackPanel> </Window>前台代码
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using System.ComponentModel; using System.Windows; namespace WpfApp1 { /// <summary> /// MainWindow.xaml 的交互逻辑 /// </summary> public partial class MainWindow : Window, INotifyPropertyChanged { public MainWindow() { InitializeComponent(); DataContext = this; } private string _inTexts; public string InTexts { get { return _inTexts; } set { _inTexts = value; OnPropertyChanged("InTexts"); if (isNumberic(InTexts) == false) Comments = "请输入数字"; else Comments = null; } } private string _comments; public string Comments { get { return _comments; } set { _comments = value; OnPropertyChanged("Comments"); } } protected bool isNumberic(string message) { System.Text.RegularExpressions.Regex rex = new System.Text.RegularExpressions.Regex(@"^\d+$"); if (rex.IsMatch(message)) return true; else return false; } public event PropertyChangedEventHandler PropertyChanged; protected void OnPropertyChanged(string info) { var handler = PropertyChanged; handler?.Invoke(this, new PropertyChangedEventArgs(info)); } } }后台代码
标签:OnPropertyChanged,return,string,System,Comments,WPF,文本,public,输入 From: https://www.cnblogs.com/lizhiqiang0204/p/16708367.html