WPF 我怎样才能用 1 个事件处理程序做到这一点

Question

I have a problem, i have 5 buttons that load txt files from system and show it as string on textblocks but i dont know how to do it without 5 event handlers

    private void OnClick1(object sender, RoutedEventArgs e)
            {            
                OpenFileDialog openFileDialog = new OpenFileDialog();
                if (openFileDialog.ShowDialog() == true)
                numbers1.Text = File.ReadAllText(openFileDialog.FileName);
            }

OnClick1 is button1, numbers1 is a textblock1 now i have 5 codes like this (with numbers2.Text, numbers3.Text etc) how can i do it shorter

Answer 1

This should get you started I think

private void btnLoad_Click(object sender, RoutedEventArgs e)
        {
            OpenFileDialog openFileDialog = new OpenFileDialog();
            openFileDialog.Multiselect = true;
            List<TextBlock> textBlocks = new List<TextBlock>();
            textBlocks.Add(txt1);
            textBlocks.Add(txt2);
            textBlocks.Add(txt3);
            textBlocks.Add(txt4);
            textBlocks.Add(txt5);

            int count = 0;
          
            if (openFileDialog.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                
                foreach (String files in openFileDialog.FileNames)
                {
                    var currentText = textBlocks[count];
                    currentText.Text = File.ReadAllText(files);
                    count++;
                }
                
               
            }
        }

Here is the xaml code

<StackPanel Orientation="Vertical" HorizontalAlignment="Center" Margin="5">
            <Button Name="btnLoad" Content="Load All" Click="btnLoad_Click" ></Button>
            <TextBlock x:Name="txt1" HorizontalAlignment="Left" Margin="5" TextWrapping="Wrap" Text="TextBlock" VerticalAlignment="Top" Width="118"/>
            <TextBlock x:Name="txt2" HorizontalAlignment="Left" Margin="5"  TextWrapping="Wrap" Text="TextBlock" VerticalAlignment="Top" Width="118"/>
            <TextBlock x:Name="txt3" HorizontalAlignment="Left" Margin="5" TextWrapping="Wrap" Text="TextBlock" VerticalAlignment="Top" Width="118"/>
            <TextBlock x:Name="txt4" HorizontalAlignment="Left" Margin="5" TextWrapping="Wrap" Text="TextBlock" VerticalAlignment="Top" Width="118"/>
            <TextBlock x:Name="txt5" HorizontalAlignment="Left" Margin="5" TextWrapping="Wrap" Text="TextBlock" VerticalAlignment="Top" Width="118"/>
        </StackPanel>

Answer 2

I may be misunderstanding what you are asking. However, if you want the different buttons to use the same click event. Then the click event is going to have to be able to distinguish “which” button was clicked in order to know which text box to use.

In this case, I recommend you give each button a name and then in the click event, cast the sender as a Button , then check its name to determine which text box to use. All buttons are wired up to this ONE (1) event. Example something like…

private void btn_Click(object sender, RoutedEventArgs e) {
  Button btnSender = (Button)sender;
  TextBox tb = null;
  switch (btnSender.Name) {
    case "btn1":
      tb = txt1;
      break;
    case "btn2":
      tb = txt2;
      break;
    case "btn3":
      tb = txt3;
      break;
    case "btn4":
      tb = txt4;
      break;
  }
  if (tb != null) {
    OpenFileDialog openFileDialog = new OpenFileDialog();
    if (openFileDialog.ShowDialog() == true)
      tb.Text = File.ReadAllText(openFileDialog.FileName);
  }
}