Question

所以我在Visual Studio C＃中创建个人项目

我对C＃和编码很新。我创建了一个登录面板，我想要一种存储数据的方法，而不需要数据库服务器，更像是文本文件。

如图所示存储

--------------------
      Profiles
[Username] [Password]
Admin       123abc
Test        imboss
--------------------

并且毕竟它有一个检查方法来查看是否 usernameTextBox和passwordTextBox等于任何配置文件。

private void loginButton_Click(object sender, EventArgs e)
{
    string username, password;
    username = textBox1.Text;
    password = textBox2.Text;


    if ("userProfileName".ToString() == username && "userPassword".ToString() == password)
    {
        //login
    }
    else
    {
        MessageBox.Show("You have entered a wrong user name or password!");
    }
}

Answer 1

一种简单的方法是将用户名和密码存储在app.config文件中。

        var userPassword = ConfigurationManager.AppSettings[username];

        if (userPassword == password)
        {
            MessageBox.Show("Welcome");
        } else {
            MessageBox.Show("You have entered a wrong user name or password!");
        }

可以使用ConfigurationManger类从文件中读取值。要使用该类，您需要在文件顶部添加引用和使用语句。

import React, { Component } from 'react';
import {
  StyleSheet,
  View,
  Switch,
  ListView
} from 'react-native';

export default class FriendListBody extends Component {
   ds = new ListView.DataSource({ rowHasChanged: (r1, r2) => r1 !== r2       });

  constructor(props) {
    super(props);

    let friends = this.props.friends.map((friend) => {
      return {
        ...friend,
        selected: false
      }
    });

    this.state = {
      datasource: this.ds.cloneWithRows(friends),
      friends
    };

    this._renderRow= this._renderRow.bind(this);
    this._setValue = this._setValue.bind(this);
  }

  render() {
    return (
      <View style={styles.container}>
        <ListView
          dataSource={this.state.datasource}
          renderRow={this._renderRow}
          style={styles.listView}
          enableEmptySections={true}
        />
      </View>
    );
  }

  _setValue(id, value) {
    let newList = this.state.friends.slice();
    let pos = -1;

    for (let i = 0; i < this.state.friends.length; i++) {
      if (id === this.state.friends[i]._id) {
        pos = i;
        break;
      }
    }

    newList[pos].selected = value;
    const datasource = this.ds.cloneWithRows(newList);

    this.setState({ 
      friends: newList, 
      datasource: datasource
    );
  }

  _renderRow(rowData) {
    return (
      <View key={rowData._id} style={{ borderRadius: 10 }}>
        <Switch
          onValueChange={(value) => this._setValue(rowData._id, value)}
          style={{ marginBottom: 10 }}
          value={ rowData.selected } />
      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: '#d9d9d9',
  },
  listView: {
    flex: 1,
    borderColor: 'grey'
  }
});

Answer 2

            using System.Data;
            using System.Data.SqlClient;

            SqlConnection conn = new SqlConnection("Data Source=IP; Initial Catalog=DataBaseName; User Id=sa; password=123;");
            conn.Open();
            SqlCommand cmd = new SqlCommand("SELECT * FROM Profiles WHERE USERNAME=@USERNAME AND PASSWORD=@PASSWORD", conn);
            cmd.Parameters.AddWithValue("@USERNAME",textBox1.Text);
            cmd.Parameters.AddWithValue("@PASSWORD",textBox2.Text);
            if(cmd.ExecuteNonQuery()>0)
            {
               //Login
            }
            else
            {
               MessageBox.Show("You have entered a wrong user name or password!");
            }
            conn.Close();

登录数据库C＃没有SQL

2 个答案: