1. 程式人生 > >如何實現WPF登陸介面的記住賬號密碼功能()

如何實現WPF登陸介面的記住賬號密碼功能()

在這裡插入圖片描述
剛開始學程式設計。學了三個月了,學的C#和.net(貌似有點坑),公司應該是讓做b/s,socket和資料庫比較難,暫時不怎麼會,對WPF花的時間比較多一些(畢竟視覺化效果看起來比價有成就感)(WPF的課程案例貌似不多,加油)
新手菜鳥,大神勿噴。我覺得幾個有趣的地方,左上角的【HIM是畫的,因為這樣縮放清晰度一樣,刺激。

<Polygon Fill="DarkSlateGray" Stroke="DarkSlateGray" StrokeThickness="1" FillRule="EvenOdd" Points="5,5 67,5 62,13 25,13 25,47 62,47 67,55 5,55"/>

圖片那個是把一個TabControl控制元件翻轉了180°

<TabControl.RenderTransform>
                    <RotateTransform Angle="180"/>
                </TabControl.RenderTransform>

好了,接下來看如何記住賬號密碼功能。主要是兩個文字框,一個是textbox,另一個是passwordbox,還有一個記住密碼的勾選框

<TextBox Name="txt_UserName"  Text="{Binding Path=SaveLoginID}"
                HorizontalAlignment="Center" VerticalAlignment="Bottom" Width="200" Height="40"></TextBox>
<PasswordBox Name="txt_PSW"  PasswordChar="*" 
                                 local:PasswortBoxHelper.Attach="True" local:PasswortBoxHelper.Password="{Binding Path=SaveLoginPSW,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"
                                 HorizontalAlignment="Center" VerticalAlignment="Center" Width="200" Height="40"></PasswordBox>
<CheckBox Name="LoginIDMemory"  IsChecked="{Binding Path=SaveUser}">記住密碼</CheckBox>

可以將控制元件的值儲存在視窗中,但是這樣做之後缺乏靈活性,會將應用程式資料與UI介面混在一起,並不是一種好的設計。我們應該新建一個類,並將使用者所做的選擇儲存在其中。
(1)新建一個類,將其命名為SaveOptions
(2)我們要記住CheckBox,TextBox,PasswordBox的值,輸入以下程式碼

using System;

namespace DataEntity
{
    [Serializable]
    public class SaveOptions
    {
        private bool _SaveUser = false;
        public bool SaveUser
        {
            get { };
            set { };
        }

        private string _SaveLoginID;
        public string SaveLoginID
        {
            get { };
            set { };
        }

        private string _SaveLoginPSW;
        public string SaveLoginPSW
        {
            get { };
            set { };
        }
    } 
}

(3)返回程式碼隱藏檔案(我的是 登陸.xaml.cs),新增一個private欄位來儲存saveOptions例項;並在建構函式中新增以下程式碼。

using System.Windows;
using System.IO;
using System.Xml.Serialization;

namespace CfyDWS
{
    /// <summary>
    /// 登入.xaml 的互動邏輯
    /// </summary>
    public partial class LoginWindow : Window
    {
        private SaveOptions saveOptions;

        public LoginWindow()
        {
            if (saveOptions == null)
            {
                //確定指定的檔案是否存在
                if (File.Exists("SaveOptions.xml"))
                {
                    using (var stream = File.OpenRead("SaveOptions.xml"))
                    {
                        var serializer = new XmlSerializer(typeof(SaveOptions));
                        saveOptions = serializer.Deserialize(stream) as SaveOptions;
                    }
                }
                else
                    saveOptions = new SaveOptions();
            }
            InitializeComponent();
        }
}

接下來建立動態繫結
(4)在InitializeComponent();這一行之前加上一下程式碼:

DataContext = saveOptions;

(5)轉到SaveOptions類,對其進行修改

using System;
using System.ComponentModel;

namespace DataEntity
{
    [Serializable]
    public class SaveOptions : INotifyPropertyChanged
    {
        private bool _SaveUser = false;
        public bool SaveUser
        {
            get { return _SaveUser; }
            set
            {
                _SaveUser = value;
                OnPropertyChanged(nameof(SaveUser));
            }
        }

        private string _SaveLoginID;
        public string SaveLoginID
        {
            get { return _SaveLoginID; }
            set
            {
                _SaveLoginID = value;
                OnPropertyChanged(nameof(SaveLoginID));
            }
        }

        private string _SaveLoginPSW;
        public string SaveLoginPSW
        {
            get { return _SaveLoginPSW; }
            set
            {
                _SaveLoginPSW = value;
                OnPropertyChanged(nameof(SaveLoginPSW));
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;
        public void OnPropertyChanged(string propertyName)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

(6)返回登陸.xaml檔案,選擇CheckBox,然後新增IsChenk屬性,如下所示:

IsChecked="{Binding Path=SaveUser}"

(7)同理繫結TextBoX控制元件的Text屬性

Text="{Binding Path=SaveLoginID}"

(8)繫結PasswordBox的Password屬性時會出現一個錯誤,PasswordBox的Password屬性不是依賴項屬性,無法繫結。
其原因是,出於安全考慮,對密碼進行資料庫不是一個很好的設計,因此應該避免。但是有時這種安全性是不必要的,那麼不能繫結到Password屬性就很麻煩了。在這種特殊情況下,您可以利用以下PasswordBoxHelper。程式碼如下

http://www.wpftutorial.net/PasswordBox.html

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;

namespace CfyDWS
{
    public static class PasswortBoxHelper
    {
        //通過呼叫PasswordHelper.Attach財產。附加財產PasswordHelper.Password提供PasswordBox控制元件的原始密碼屬性的可繫結副本。
        public static readonly DependencyProperty PasswordProperty =
        DependencyProperty.RegisterAttached("Password",
        typeof(string), typeof(PasswortBoxHelper),
        new FrameworkPropertyMetadata(string.Empty, OnPasswordPropertyChanged));

        public static readonly DependencyProperty AttachProperty =
            DependencyProperty.RegisterAttached("Attach",
            typeof(bool), typeof(PasswortBoxHelper), new PropertyMetadata(false, Attach));

        private static readonly DependencyProperty IsUpdatingProperty =
           DependencyProperty.RegisterAttached("IsUpdating", typeof(bool),
           typeof(PasswortBoxHelper));


        public static void SetAttach(DependencyObject dp, bool value)
        {
            dp.SetValue(AttachProperty, value);
        }

        public static bool GetAttach(DependencyObject dp)
        {
            return (bool)dp.GetValue(AttachProperty);
        }

        public static string GetPassword(DependencyObject dp)
        {
            return (string)dp.GetValue(PasswordProperty);
        }

        public static void SetPassword(DependencyObject dp, string value)
        {
            dp.SetValue(PasswordProperty, value);
        }

        private static bool GetIsUpdating(DependencyObject dp)
        {
            return (bool)dp.GetValue(IsUpdatingProperty);
        }

        private static void SetIsUpdating(DependencyObject dp, bool value)
        {
            dp.SetValue(IsUpdatingProperty, value);
        }

        private static void OnPasswordPropertyChanged(DependencyObject sender,
            DependencyPropertyChangedEventArgs e)
        {
            PasswordBox passwordBox = sender as PasswordBox;
            passwordBox.PasswordChanged -= PasswordChanged;

            if (!(bool)GetIsUpdating(passwordBox))
            {
                passwordBox.Password = (string)e.NewValue;
            }
            passwordBox.PasswordChanged += PasswordChanged;
        }

        private static void Attach(DependencyObject sender,
            DependencyPropertyChangedEventArgs e)
        {
            PasswordBox passwordBox = sender as PasswordBox;

            if (passwordBox == null)
                return;

            if ((bool)e.OldValue)
            {
                passwordBox.PasswordChanged -= PasswordChanged;
            }

            if ((bool)e.NewValue)
            {
                passwordBox.PasswordChanged += PasswordChanged;
            }
        }

        private static void PasswordChanged(object sender, RoutedEventArgs e)
        {
            PasswordBox passwordBox = sender as PasswordBox;
            SetIsUpdating(passwordBox, true);
            SetPassword(passwordBox, passwordBox.Password);
            SetIsUpdating(passwordBox, false);
        }
    }
}

檢視登陸.xaml視窗,看到有名稱空間CfyDWS的引用,沒有的話自己手動新增,要引用CfyDWS名稱空間下的PasswordBoxHelper類的方法。

<Window x:Class="CfyDWS.LoginWindow"
        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:CfyDWS"
        mc:Ignorable="d"
        WindowStartupLocation="CenterScreen"
        Title="登入視窗" Icon="image\昌恆圖示.png" Height="780" Width="1460" ResizeMode="CanMinimize">

然後修改PasswordBox的屬性

<PasswordBox Name="txt_PSW"  PasswordChar="*" 
                                 local:PasswortBoxHelper.Attach="True" local:PasswortBoxHelper.Password="{Binding Path=SaveLoginPSW, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"></PasswordBox>

這裡說下看到的另一個方法,用TextBox替換PasswordBox,然後用TextDecorations屬性畫小黑點裝飾TextBox,這種感覺視窗大小最好固定吧。而且小圓點的大小不好把握,也可能是我這裡學的差。

https://blog.csdn.net/SANYUNI/article/details/52775898

(9)我把儲存選項放在登陸按鈕上了
這裡我是當按下確定時,假如賬號密碼不對,未勾選記住密碼,則清空賬號密碼框,如果正確,則登入
這裡主要看using()的那一段程式碼段

        private void btn_login_Click(object sender, RoutedEventArgs e)
        {
            SqlConnectionStringBuilder connbuilder = new SqlConnectionStringBuilder();
            connbuilder.DataSource = Environment.MachineName;                             //獲取伺服器名稱,本機為Cheng-PC(data ource資料來源,一般為機器名稱或IP地址)
            connbuilder.IntegratedSecurity = true;                                        //登入方式,true為 Windows 身份驗證
            connbuilder.InitialCatalog = "昌恆DWS系統";                                   //資料庫名(Initial Catalog資料庫或SQL Server例項的名稱(與Database一樣))

            SqlConnection conn = new SqlConnection(connbuilder.ConnectionString);         //建立一個SqlConnecting物件並且初始化連線字串
            conn.Open();                                                                  //開啟資料庫連線
            string a = string.Format("select * from 賬戶管理 where login_ID='{0}' and login_PSW='{1}' ", txt_UserName.Text, txt_PSW.Password);   
                                                                                          //定義要執行的SQL語句(本處是查詢語句)
            SqlCommand comm = new SqlCommand(a, conn);                                    //建立SqlCommand的例項物件(string a表示要查詢的文字,SqlConnecting conn表示到SQL Server例項的連線)
            SqlDataReader dr = comm.ExecuteReader();                                      //ExecuteReader(),讀取資料,生成一個SqlDataReader物件並返回
            if (txt_UserName.Text == "" || txt_PSW.Password == "") //判斷輸入是否為空
            {
                MessageBox.Show("請填寫使用者名稱和密碼");
                using (var stream = File.Open("SaveOptions.xml", FileMode.Create))
                {
                    if (LoginIDMemory.IsChecked == false)
                    {
                        saveOptions.SaveLoginID = "";
                        saveOptions.SaveLoginPSW = "";
                    }
                    var serializer = new XmlSerializer(typeof(SaveOptions));
                    serializer.Serialize(stream, saveOptions);
                }
            }

            else
            {
                if (dr.Read())//判斷是否存在使用者輸入的使用者名稱和密碼
                {
                    MessageBox.Show("登陸成功"); // 顯示主視窗;
                    this.DialogResult = Convert.ToBoolean(1);
                    using (var stream = File.Open("SaveOptions.xml", FileMode.Create))
                    {
                        if (LoginIDMemory.IsChecked == false)
                        {
                            saveOptions.SaveLoginID = "";
                            saveOptions.SaveLoginPSW = "";
                        }
                        var serializer = new XmlSerializer(typeof(SaveOptions));
                        serializer.Serialize(stream, saveOptions);
                    }
                    conn.Close();                                                          //關閉資料庫連線
                    this.Close();
                }

                else
                {
                    MessageBox.Show("使用者名稱或密碼有誤");
                    using (var stream = File.Open("SaveOptions.xml", FileMode.Create))
                    {
                        if (LoginIDMemory.IsChecked == false)
                        {
                            saveOptions.SaveLoginID = "";
                            saveOptions.SaveLoginPSW = "";
                        }
                        var serializer = new XmlSerializer(typeof(SaveOptions));
                        serializer.Serialize(stream, saveOptions);
                    }
                    conn.Close();                                                          //關閉資料庫連線
                }
            }
        }

這裡的using程式碼段也可以寫進一個void方法裡,直接呼叫方法

using (var stream = File.Open("SaveOptions.xml", FileMode.Create))
                    {
                        if (LoginIDMemory.IsChecked == false)
                        {
                            saveOptions.SaveLoginID = "";
                            saveOptions.SaveLoginPSW = "";
                        }
                        var serializer = new XmlSerializer(typeof(SaveOptions));
                        serializer.Serialize(stream, saveOptions);
                    }
``