【C#】上机实验九

1. 设计一个Windows登陆窗体应用程序，能够实现根据现有表中数据模拟登陆，并设置相关属性，具体界面如下。

可能使用到的类：

（1）SqlConnection

（2）SqlCommand

（3）SqlDataReader

（4）MessageBox

 1 using System;
 2 using System.Collections.Generic;
 3 using System.ComponentModel;
 4 using System.Data;
 5 using System.Drawing;
 6 using System.Linq;
 7 using System.Text;
 8 using System.Windows.Forms;
 9 using System.Data.SqlClient;
10 
11 namespace Myform
12 {
13     public partial class Form1 : Form
14     {
15         public Form1()
16         {
17             InitializeComponent();
18         }
19 
20         private void label1_Click(object sender, EventArgs e)
21         {
22 
23         }
24 
25         private void button1_Click(object sender, EventArgs e)
26         {
27             
28             string connString = @"Data Source=(LocalDB)MSSQLLocalDB;AttachDbFilename=D:C#09J20172202899何海钊MyformMyformPropertiesDatabase1.mdf;Integrated Security=True";
29             SqlConnection conn = null;
30             SqlCommand cmd = null;
31             SqlDataReader reader = null;
32             try
33             {
34                 conn = new SqlConnection(connString);
35                 conn.Open();
36                 cmd = conn.CreateCommand();
37                 cmd.CommandText = "Select username , password From Table1 where username = @username and password = @password ";
38                 cmd.Parameters.AddWithValue("@username", textBox1.Text.Trim());
39                 cmd.Parameters.AddWithValue("@password", textBox2.Text.Trim());
40                 reader = cmd.ExecuteReader();
41                 if (reader.Read())
42                 {
43                     MessageBox.Show("登录成功", "OK", MessageBoxButtons.OK, MessageBoxIcon.Information);
44                 }
45                 else
46                 {
47                     MessageBox.Show("用户名密码不正确", "NO", MessageBoxButtons.OK, MessageBoxIcon.Error);
48                 }
49                 
50             }
51             catch (Exception ex)
52             {
53                 MessageBox.Show(ex.Message, "Open Error", MessageBoxButtons.OK);
54             }
55             finally 
56             {
57                 if (reader != null) reader.Close();
58                 if (conn.State == ConnectionState.Open) conn.Close();
59             }
60         }
61     }
62 }
Code1

2、设计一个Windows登陆窗体应用程序，根据下图设置相关属性，该程序能够读写现有表中数据，具体界面如下。

 1 using System;
 2 using System.Collections.Generic;
 3 using System.ComponentModel;
 4 using System.Data;
 5 using System.Drawing;
 6 using System.Linq;
 7 using System.Text;
 8 using System.Windows.Forms;
 9 using System.Data.SqlClient;
10 
11 namespace Myform2
12 {
13     public partial class Form1 : Form
14     {
15         public Form1()
16         {
17             InitializeComponent();
18         }
19 
20         private SqlConnection conn = null;
21         private SqlCommand cmd = null;
22         private SqlDataReader reader = null;
23         private SqlDataAdapter adapter = null;
24         private DataSet List = null;
25         
26         private string connString = @"Data Source=(LocalDB)MSSQLLocalDB;AttachDbFilename=D:C#09J20172202899何海钊dbDatabase1.mdf;Integrated Security=True;Connect Timeout=30";
27 
28         private void button1_Click(object sender, EventArgs e)
29         {
30             try
31             {
32                 conn = new SqlConnection(connString);
33                 conn.Open();
34                 cmd = conn.CreateCommand();
35                 cmd.CommandText = "Insert into Table1 ( username , password ) values (@username , @password ) ";
36                 cmd.Parameters.AddWithValue("@username", textBox1.Text.Trim());
37                 cmd.Parameters.AddWithValue("@password", textBox2.Text.Trim());
38                 int n = cmd.ExecuteNonQuery();
39                 if ( n > 0 )
40                 {
41                     MessageBox.Show("成功插入", "Insert OK ", MessageBoxButtons.OK, MessageBoxIcon.Information);
42                 }
43                 else
44                 {
45                     MessageBox.Show("插入失败", "Insert error", MessageBoxButtons.OK, MessageBoxIcon.Error);
46                 }
47 
48             }
49             catch (Exception ex)
50             {
51                 MessageBox.Show(ex.Message, "Open Error", MessageBoxButtons.OK);
52             }
53             finally
54             {
55                 if (reader != null) reader.Close();
56                 if (conn.State == ConnectionState.Open) conn.Close();
57             }
58         }
59 
60         private void button2_Click(object sender, EventArgs e)
61         {
62             try
63             {
64                 conn = new SqlConnection(connString);
65                 conn.Open();
66                 cmd = conn.CreateCommand();
67                 cmd.CommandText = "Select * From Table1 ";
68 
69                 adapter = new SqlDataAdapter(cmd);
70 
71                 List = new DataSet();
72 
73                 adapter.Fill(List);
74                 DataTable table = List.Tables[0];
75 
76                 DataRowCollection Rows = table.Rows;
77 
78                 for (int i = 0; i < Rows.Count; i++)
79                 {
80                     DataRow row = Rows[i];
81                     string username = (string)row["username"];
82                     string password = (string)row["password"];
83 
84                     this.richTextBox1.Text += username + " " + password + "
";
85                 }
86             }
87             catch (Exception ex)
88             {
89                 MessageBox.Show(ex.Message, "Open Error", MessageBoxButtons.OK);
90             }
91             finally
92             {
93                 if (reader != null) reader.Close();
94                 if (conn.State == ConnectionState.Open) conn.Close();
95             }
96         }
97     }
98 }
Code2

3、设计一个Windows窗体应用程序，根据下图设置相关属性，该程序能够读取AdventureWorksDW_Data.mdf数据库中DimReseller表中数据，具体界面如下。

  1 using System;
  2 using System.Collections.Generic;
  3 using System.ComponentModel;
  4 using System.Data;
  5 using System.Drawing;
  6 using System.Linq;
  7 using System.Text;
  8 using System.Threading.Tasks;
  9 using System.Windows.Forms;
 10 using System.Data.SqlClient;
 11 
 12 namespace FormPage
 13 {
 14     public partial class Form1 : Form
 15     {
 16 
 17 
 18         private SqlConnection conn = null;
 19         private SqlCommand cmd = null;
 20         private SqlDataAdapter adapter = null;
 21         private SqlDataReader reader = null;
 22         private DataSet ds = null;
 23 
 24         private int pageSize = 10;
 25         private int rowCount = 0;
 26         private int pageNum = 0;
 27         private string connectString = @"Data Source=(LocalDB)MSSQLLocalDB;AttachDbFilename=D:C#09J20172202899何海钊MyForm3AdventureWorksDW2008AdventureWorksDW_Data.mdf;Integrated Security=True;Connect Timeout=30";
 28 
 29         public Form1()
 30         {
 31             InitializeComponent();
 32             Count_Row();
 33             Fill_Data();
 34         }
 35 
 36         private void btn_FirstPage_Click(object sender, EventArgs e)
 37         {
 38             pageNum = 0;
 39             Fill_Data();
 40         }
 41 
 42         
 43         private void btn_LastPage_Click(object sender, EventArgs e)
 44         {
 45             pageNum = rowCount/pageSize;
 46             Fill_Data();
 47         }
 48 
 49         private void btn_PrePage_Click(object sender, EventArgs e)
 50         {
 51             if( pageNum > 0 )
 52             {
 53                 pageNum--;
 54                 Fill_Data();
 55             }
 56         }
 57 
 58         private void btn_NextPage_Click(object sender, EventArgs e)
 59         {
 60             if (pageNum < rowCount / pageSize)
 61             {
 62                 pageNum++;
 63                 Fill_Data();
 64             }
 65             
 66         }
 67         private void btn_Fill_Click(object sender, EventArgs e)
 68         {
 69             Fill_Data();
 70         }
 71         void Fill_Data()
 72         {
 73             if (pageNum == 0)
 74             {
 75                 btn_FirstPage.Enabled = false;
 76                 btn_PrePage.Enabled = false;
 77             }
 78             else
 79             {
 80                 btn_FirstPage.Enabled = true;
 81                 btn_PrePage.Enabled = true;
 82             }
 83 
 84             if( pageNum == rowCount / pageSize)
 85             {
 86                 btn_LastPage.Enabled = false;
 87                 btn_NextPage.Enabled = false;
 88             }
 89             else
 90             {
 91                 btn_LastPage.Enabled = true;
 92                 btn_NextPage.Enabled = true;
 93             }
 94             try
 95             {
 96                 conn = new SqlConnection(connectString);
 97                 conn.Open();
 98 
 99                 cmd = conn.CreateCommand();
100                 cmd.CommandText = "Select top ("+pageSize+ ") Employeekey , FirstName , LastName , EmailAddress , Phone from DimEmployee where EmployeeKey not in( Select top (" + pageSize *pageNum+ ") EmployeeKey from DimEmployee order by EmployeeKey ) order by EmployeeKey";
101 
102 
103 
104                 ds = new DataSet();
105                 adapter = new SqlDataAdapter(cmd);
106                 adapter.Fill(ds , "DimEmployee" );
107 
108                 dataGridView1.DataSource = ds;
109                 dataGridView1.DataMember = "DimEmployee";
110 
111             }
112             catch (Exception ex)
113             {
114                 MessageBox.Show(ex.Message, "Fill Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
115             }
116             finally
117             {
118                 if (conn.State == ConnectionState.Open)
119                     conn.Close();
120             }
121         }
122 
123         void Count_Row()
124         {
125             try
126             {
127                 conn = new SqlConnection(connectString);
128                 conn.Open();
129 
130                 cmd = conn.CreateCommand();
131                 cmd.CommandText = "Select count(*) from DimEmployee";
132 
133                 reader = cmd.ExecuteReader();
134                 if( reader.Read())
135                 {
136                     rowCount = reader.GetInt32(0);
137                 }
138                 else
139                 {
140                     MessageBox.Show("Search Error", "0 row", MessageBoxButtons.OK, MessageBoxIcon.Error);
141                 }
142                 if (reader.IsClosed)
143                     reader.Close();
144             }
145             catch (Exception ex)
146             {
147                 MessageBox.Show(ex.Message, "Search Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
148             }
149             finally
150             {
151                 if (conn.State == ConnectionState.Open)
152                     conn.Close();
153                 if( reader.IsClosed)
154                     reader.Close();
155             }
156         }
157     }
158 }
Code3
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原文地址：https://www.cnblogs.com/Osea/p/11872356.html