输入验证 Silverlight

发布于 2024-12-06 21:49:45 字数 277 浏览 0 评论 0原文

我有一个未绑定的文本框。

<TextBox x:Name="inputBox" Grid.Column="1" Grid.Row="1"  />

文本框仅接受数字（双精度），并在将其他内容（字母或符号）写入框中时显示警告。

在 TextChanged 事件中，我根据输入的值进行一些计算并将其显示在 TextBlock 中，因此我需要某种方法来验证输入是用户在框中写入的数字，但我很难找到一个好方法来做到这一点。

有什么想法吗？

原文

i have a textbox which is not bound.

<TextBox x:Name="inputBox" Grid.Column="1" Grid.Row="1"  />

The textbox is to only accept numbers (doubles) and show a warning at once something else(letters or symbols) is written in to the box.

On the TextChanged event, i do some calculations depending on the value enterd and show it in a TextBlock, therefor i need some way of validating that the input is a number as the user writes in the box, but i am having a hard time finding a good way to do this.

Any ideas?

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零度° 2024-12-13 21:49:45

我之前使用的是正则表达式来禁止非数字字符。也许这是可以适应的东西？

我的代码是针对服务器上的端口的，因此只有数字，但应该很容易添加 .对于双打（我认为“[^0-9\.]”应该有效，但正则表达式不是我非常擅长的东西:-)）

// Text change in Port text box
private void txtPort_TextChanged(object sender, TextChangedEventArgs e)
{
    // Only allow numeric input into the Port setting.
    Regex rxAllowed = new Regex(@"[^0-9]", RegexOptions.IgnoreCase);

    txtPort.Text = rxAllowed.Replace(txtPort.Text, ""); 
    txtPort.SelectionStart = txtPort.Text.Length; 
}

What I have used before is a regex to disallow non-numeric characters. Maybe this is something that could be adapted?

My code was for a port on a server so only numbers but should be straightforward to add the . for doubles (I think "[^0-9\.]" should work but regexs aren't something I am fantastically good at :-) )

// Text change in Port text box
private void txtPort_TextChanged(object sender, TextChangedEventArgs e)
{
    // Only allow numeric input into the Port setting.
    Regex rxAllowed = new Regex(@"[^0-9]", RegexOptions.IgnoreCase);

    txtPort.Text = rxAllowed.Replace(txtPort.Text, ""); 
    txtPort.SelectionStart = txtPort.Text.Length; 
}

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分开我的手 2024-12-13 21:49:45

这是何时使用行为的另一个示例。

public class TextBoxValidator : Behavior<TextBox>
{
  protected override void OnAttached()
  {
    AssociatedObject.TextChanged += new TextChanged(OnTextChanged);
  }

  private void OnTextChanged(object sender, TextChangedEventArgs e)
  {
    // Here you could add the code shown above by Firedragon or you could
    // just use int.TryParse to see if the number if valid.
    // You could also expose a Regex property on the behavior to allow lots of
    // types of validation
  }
}

您没有真正解释当用户输入无效值时您想要采取什么操作。

This is another example of when to use a Behavior.

public class TextBoxValidator : Behavior<TextBox>
{
  protected override void OnAttached()
  {
    AssociatedObject.TextChanged += new TextChanged(OnTextChanged);
  }

  private void OnTextChanged(object sender, TextChangedEventArgs e)
  {
    // Here you could add the code shown above by Firedragon or you could
    // just use int.TryParse to see if the number if valid.
    // You could also expose a Regex property on the behavior to allow lots of
    // types of validation
  }
}

You didn't really explain what actions you wanted to take when the user enters an invalid value.

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