文本框保存最后输入的值

Question

I have a project with Form and WPF(xaml) that popup with button click in the Form. The WPF have TextBoxes that the user can enter some values then to click to use these values in my project. what Im trying to achieve is that in the first call the user enter values and if he call it again, the TextBoxes shows the last entered values. Also I want to prevent the user from entered value for example here less than 1.

Here is my WPF code:

<Window x:Class="Alarms.AlarmsFC_Popup"
        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:Alarms"
        mc:Ignorable="d"
        Title="Alarms" Height="150" Width="525" Background="LightSteelBlue" Icon="warningred.ico">
    <Border Padding="10">
    <StackPanel>
            <!--IO Fields-->
            <Grid>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="*"/>
                    <ColumnDefinition Width="*"/>
                </Grid.ColumnDefinitions>

                <!--Begin Alarm-->
                <StackPanel Grid.Column="0" Margin="0 0 10 0">
                    <TextBlock Text="Number From" FontWeight="Black"/>
                    <TextBox x:Name="BeginAlarmBox1" Padding="1" Margin="0 5 0 0" Background="White" Text="1"></TextBox>
                </StackPanel>

                <!--End Alarm-->
                <StackPanel Grid.Column="1" Margin="0 0 0 0">
                    <TextBlock Text="Number To" FontWeight="Black"/>
                    <TextBox x:Name="EndAlarmBox1" Padding="1" Margin="0 5 0 0" Background="White" Text="32"></TextBox>
                </StackPanel>
            </Grid>

            <!--Buttons-->
            <Grid Margin="0,10,0,0">
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="*"/>
                    <ColumnDefinition Width="*"/>
                </Grid.ColumnDefinitions>
                <Button Name="BtnExport" Content="Export" Grid.Column="0" Margin="0,10,10,0" Padding="8" Click="BtnExport_Click" />
                <Button Name="BtnCancel" Content="Cancel" Grid.Column="1" Margin="10,10,0,0" Padding="8" Click="BtnCancel_Click" />
            </Grid>

        </StackPanel>
    </Border>
</Window>

And the code behind

public partial class AlarmsFC_Popup : Window
    {
        public AlarmsFC_Popup(int BAlarm)
        {
            InitializeComponent();
            BeginAlarm = BAlarm;
        }
        public int BeginAlarm
        {
            get { return int.Parse(BeginAlarmBox1.Text); }
            set { 
                BeginAlarmBox1.Text = value.ToString();
                if (value < 1) MessageBox.Show("Value has to be 1 or higher!");
                }
        }
        private void BtnExport_Click(object sender, RoutedEventArgs e)
        {
            if (!String.IsNullOrEmpty(BeginAlarmBox1.Text)) && (!String.IsNullOrEmpty(EndAlarmBox1.Text))
            {
                BeginAlarm = int.Parse(BeginAlarmBox1.Text);

                    MessageBox.Show(String.Format("Your for loop start at {0}", BeginAlarm.ToString()));
                    this.Close();
            }
            else
            {
                MessageBox.Show("One or more fields are empty. Fill all fields then press Export!");
            }

        }
        private void BtnCancel_Click(object sender, RoutedEventArgs e)
        {
            //MessageBox.Show("You clicked me at " + e.GetPosition(this).ToString());
        }
    }

Then I call it in my main Form

private void BtnAlarms_Click(object sender, EventArgs e)
        {

            AlarmsFC_Popup Alarms = new AlarmsFC_Popup(1, 32);
            Alarms .ShowDialog();
            int FirstAlarm = Alarms .BeginAlarm;
        }

What I'm doing wrong? why it doesn't hold my last entered value, instead it always shows me 1 for the begin alarm

Answer 1

You need to store the value somewhere, otherwise it goes away once you close the window.

You could for example do this using a private field in the main window:

int _beginAlarm = 1;
private void BtnAlarms_Click(object sender, EventArgs e)
{
    AlarmsFC_Popup Alarms = new AlarmsFC_Popup(_beginAlarm, 32);
    Alarms.ShowDialog();
    _beginAlarm = Alarms.BeginAlarm;
}