登录页面未以 xamarin 形式进行验证 [英] Login page is not validating in xamarin form
问题描述
我使用 xamarin 表单创建了登录页面,并创建了名为 validationbehaviour.cs 的类文件,并通过行为类验证了输入字段.
I have created login page using xamarin forms and created the class file called validationbehaviour.cs and validated input fields through behaviour class.
xaml 登录页面代码:
xaml login page code:
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:local="clr-namespace:LoginUser"
x:Class="LoginUser.MainPage">
<StackLayout Spacing="20" Padding="50" VerticalOptions="Center">
<Entry Placeholder="Username"></Entry>
<Entry Placeholder="Password" IsPassword="True">
<Entry.Behaviors>
<local:PasswordValidationBehavior />
</Entry.Behaviors>
</Entry>
<Button Text="Log In" TextColor="White" BackgroundColor="##ff77D065"></Button>
</StackLayout>
</ContentPage>
这是我的validationbehaviour.cs代码:
Here is my validationbehaviour.cs code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Xamarin.Forms;
using System.Text.RegularExpressions;
namespace LoginUser
{
public class ValidationBehavior: Behavior<Entry>
{
const string pwRegex = @"^(?=.*[A-Za-z])(?=.*d)(?=.*[$@$!%*#?&])[A-Za- zd$@$!%*#?&]{8,}$";
protected override void OnAttachedTo(Entry bindable)
{
bindable.TextChanged += HandleTextChanged;
base.OnAttachedTo(bindable);
}
private void HandleTextChanged(object sender, TextChangedEventArgs e)
{
bool IsValid = false;
IsValid= (Regex.IsMatch(e.NewTextValue, pwRegex));
((Entry)sender).TextColor = IsValid ? Color.Default : Color.Red;
}
protected override void OnDetachingFrom(Entry bindable)
{
bindable.TextChanged -= HandleTextChanged;
base.OnDetachingFrom(bindable);
}
}
}
所以当我在 android 模拟器中运行程序时,登录设计工作正常但验证不起作用.
So when I run the program in android emulator,the login design is working fine but validation is not working.
推荐答案
也许你应该将 IsValid 变量更改为这样的属性:
Maybe you should change IsValid variable to property like this:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Xamarin.Forms;
using System.Text.RegularExpressions;
namespace LoginUser
{
public class ValidationBehavior: Behavior<Entry>
{
const string pwRegex = @"^(?=.*[a-z])(?=.*[A-Z])(?=.*d)(?=.*[^da-zA-Z]).{8,15}$";
static readonly BindablePropertyKey IsValidPropertyKey = BindableProperty.CreateReadOnly("IsValid", typeof(bool), typeof(ValidationBehavior), false);
public static readonly BindableProperty IsValidProperty = IsValidPropertyKey.BindableProperty;
public bool IsValid
{
get { return (bool)base.GetValue(IsValidProperty); }
private set { base.SetValue(IsValidPropertyKey, value); }
}
protected override void OnAttachedTo(Entry bindable)
{
bindable.TextChanged += HandleTextChanged;
}
private void HandleTextChanged(object sender, TextChangedEventArgs e)
{
IsValid= (Regex.IsMatch(e.NewTextValue, pwRegex, RegexOptions.IgnoreCase, TimeSpan.FromMilliseconds(250)));
((Entry)sender).TextColor = IsValid ? Color.Default : Color.Red;
}
protected override void OnDetachingFrom(Entry bindable)
{
bindable.TextChanged -= HandleTextChanged;
}
}
}
另一个错误也是你的正则表达式,请尝试以下操作:
Another error is also your regular expression, try the following:
^(?=.*[a-z])(?=.*[A-Z])(?=.*d).{8,15}$
如果您还想要求至少一个特殊字符(这可能是个好主意),请尝试以下操作:
If you also want to require at least one special character (which is probably a good idea), try this:
^(?=.*[a-z])(?=.*[A-Z])(?=.*d)(?=.*[^da-zA-Z]).{8,15}$
使用我的示例,您会得到这样的结果:
With my sample you get like this:
使用密码:123456
使用密码:AbcDe12!
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