DataRowState、AcceptChanges、RejectChanges综合使用示例：实现DataGridView数据的增、删、改

  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;
 11 using System.Data.SqlClient;
 12 using System.Configuration;
 13 
 14 namespace DataRowStateDemo
 15 {
 16     public partial class FrmMain : Form
 17     {
 18         public FrmMain()
 19         {
 20             InitializeComponent();
 21         }
 22                                
 23         //连接字符串
 24         string strConn = ConfigurationManager.ConnectionStrings["DbConn"].ConnectionString;
 25 
 26         /// <summary>
 27         /// 加载
 28         /// </summary>
 29         /// <param name="sender"></param>
 30         /// <param name="e"></param>
 31         private void btn_LoadData_Click(object sender, EventArgs e)
 32         {
 33             Initdgv();
 34             this.btn_Add.Visible = false;
 35         }
 36 
 37         /// <summary>
 38         /// 初始化DataGridView
 39         /// </summary>
 40         private void Initdgv()
 41         {
 42             SqlConnection conn = new SqlConnection(strConn);
 43             string strSQL = "select * from Users";
 44             SqlCommand cmd = new SqlCommand(strSQL, conn);
 45             SqlDataAdapter adapter = new SqlDataAdapter(cmd);
 46             DataSet dsDgv = new System.Data.DataSet();
 47             try
 48             {
 49                 conn.Open();
 50                 //填充数据
 51                 adapter.Fill(dsDgv);
 52 
 53                 this.dgv_Demo.DataSource = dsDgv.Tables[0];
 54                 //不显示最后的空行
 55                 this.dgv_Demo.AllowUserToAddRows = false;
 56                 // 设置第一列只读
 57                 this.dgv_Demo.Columns[0].ReadOnly = true;
 58             }
 59             catch (Exception ex)
 60             { }
 61             finally
 62             {
 63                 conn.Close();
 64             }
 65         }
 66 
 67         /// <summary>
 68         /// 编辑
 69         /// </summary>
 70         /// <param name="sender"></param>
 71         /// <param name="e"></param>
 72         private void btn_Edit_Click(object sender, EventArgs e)
 73         {
 74             this.dgv_Demo.AllowUserToAddRows = true;
 75         }
 76 
 77         /// <summary>
 78         /// 保存
 79         /// </summary>
 80         /// <param name="sender"></param>
 81         /// <param name="e"></param>
 82         private void btn_Save_Click(object sender, EventArgs e)
 83         {
 84             DataTable dtCopy = this.dgv_Demo.DataSource as DataTable;
 85             DataSet dsUsers = new DataSet();
 86 
 87             //产生与表Users结构相同的空表
 88             DataTable dtAdd = GetEmptyTable();
 89             DataTable dtEdit = GetEmptyTable();
 90             DataTable dtDel = GetEmptyTable();
 91 
 92             //根据DataRowState的状态获取新增、修改、删除的表数据
 93             dtAdd = dtCopy.GetChanges(DataRowState.Added);
 94             dtEdit = dtCopy.GetChanges(DataRowState.Modified);
 95             dtDel = dtCopy.GetChanges(DataRowState.Deleted);
 96 
 97             //新增
 98             if (dtAdd != null)
 99             {
100                 dtAdd.TableName = "Added";
101                 dsUsers.Tables.Add(dtAdd);
102             }
103             //修改
104             if (dtEdit != null)
105             {
106                 dtEdit.TableName = "Edit";
107                 dsUsers.Tables.Add(dtEdit);
108             }
109             //删除
110             if (dtDel != null)
111             {
112                 dtDel.TableName = "Del";
113                 dtDel.RejectChanges();
114                 dsUsers.Tables.Add(dtDel);
115             }
116             //保存数据
117             if (SaveUser(dsUsers))
118             {
119                 MessageBox.Show("保存成功!");
120                 //重新加载数据
121                 Initdgv();
122             }
123             else
124             {
125                 MessageBox.Show("保存失败!");
126             }
127         }
128 
129         /// <summary>
130         /// 根据表结构产生空表
131         /// </summary>
132         /// <returns></returns>
133         private DataTable GetEmptyTable()
134         {
135             DataTable dtTable = new DataTable("Users");
136             //使用集合初始化器添加列
137             dtTable.Columns.AddRange(new DataColumn[]{
138                    new DataColumn("UserID",typeof(Int32)),
139                    new DataColumn("UserName",typeof(string)),
140                    new DataColumn("Password",typeof(string)),
141                    new DataColumn("Sex",typeof(Char)),
142                    new DataColumn("Birthday",typeof(DateTime))
143             });
144             return dtTable;
145         }
146 
147         /// <summary>
148         /// 保存数据
149         /// </summary>
150         /// <param name="ds"></param>
151         /// <returns></returns>
152         private bool SaveUser(DataSet ds)
153         {
154             bool tf = false;
155             //新增
156             if (ds.Tables["Added"] != null)
157             {
158                 foreach (DataRow dr in ds.Tables["Added"].Rows)
159                 {
160                    tf= InsertUser(dr);
161                 }
162             }
163             //修改
164             if (ds.Tables["Edit"] != null)
165             {
166                 foreach (DataRow dr in ds.Tables["Edit"].Rows)
167                 {
168                     tf = UpdateUser(dr);
169                 }
170             }
171             //删除
172             if (ds.Tables["Del"] != null)
173             {
174                 foreach (DataRow dr in ds.Tables["Del"].Rows)
175                 {
176                     tf = DeleteUser(dr);
177                 }
178             }
179             return tf;
180         }
181 
182         /// <summary>
183         /// 数据库增加
184         /// </summary>
185         /// <param name="drDataRow"></param>
186         /// <returns></returns>
187         private bool InsertUser(DataRow drDataRow)
188         {
189             string strSQL = string.Format(@"insert into users values(‘{0}‘,‘{1}‘,‘{2}‘,‘{3}‘)", drDataRow["UserName"].ToString(), drDataRow["Password"].ToString(), 
                                                drDataRow["Sex"].ToString(), drDataRow["Birthday"].ToString());
190             return ExecuteSQL(strSQL);
191         }
192 
193         /// <summary>
194         /// 数据库删除
195         /// </summary>
196         /// <param name="drDataRow"></param>
197         /// <returns></returns>
198         private bool DeleteUser(DataRow drDataRow)
199         {
200             string strSQL = string.Format("delete from users where UserID=‘{0}‘", Convert.ToInt32(drDataRow["UserID"].ToString()));
201             return ExecuteSQL(strSQL);
202         }
203 
204         /// <summary>
205         /// 数据库修改
206         /// </summary>
207         /// <param name="drDataRow"></param>
208         /// <returns></returns>
209         private bool UpdateUser(DataRow drDataRow)
210         {
211             string strSQL = string.Format("update users set UserName=‘{0}‘,Password=‘{1}‘,Sex=‘{2}‘,Birthday=‘{3}‘ where UserID=‘{4}‘",
212                                          drDataRow["UserName"].ToString(), drDataRow["Password"].ToString(), drDataRow["Sex"].ToString(),
213                                          drDataRow["Birthday"].ToString(), Convert.ToInt32(drDataRow["UserID"].ToString()));
214             return ExecuteSQL(strSQL);
215         }
216 
217          /// <summary>
218          /// 数据库执行SQL语句
219          /// </summary>
220          /// <param name="strSQL"></param>
221          /// <returns></returns>
222         private bool ExecuteSQL(string strSQL)
223         {
224             bool tfResult = false;
225             SqlConnection conn = new SqlConnection(strConn);
226             SqlCommand cmd = new SqlCommand(strSQL, conn);
227             try
228             {
229                 conn.Open();
230                 tfResult= cmd.ExecuteNonQuery().Equals(1);
231             }
232             catch (Exception ex)
233             { }
234             finally
235             {
236                 conn.Close();
237             }
238 
239             return tfResult;
240         }
241 
242         /// <summary>
243         /// 删除
244         /// </summary>
245         /// <param name="sender"></param>
246         /// <param name="e"></param>
247         private void btn_Del_Click(object sender, EventArgs e)
248         {
249             if (this.dgv_Demo.SelectedRows.Count <= 0)
250             {
251                 MessageBox.Show("请先选择要删除的行");
252             }
253             else
254             {
255                 foreach(DataGridViewRow dr in this.dgv_Demo.SelectedRows)
256                 {
257                     //只是删除DataGridView中显示的数据，并没有删除数据库中的数据
258                     this.dgv_Demo.Rows.Remove(dr);
259                 }
260                 
261             }
262         }
263 
264         /// <summary>
265         /// 增加空行
266         /// </summary>
267         /// <param name="sender"></param>
268         /// <param name="e"></param>
269         private void btn_Add_Click(object sender, EventArgs e)
270         {
271             //DataGridView没有绑定数据时才可以使用Add()方法增加空行
272             this.dgv_Demo.Rows.Add();
273         }
274 
275         private void FrmMain_Load(object sender, EventArgs e)
276         {
277             this.dgv_Demo.AllowUserToAddRows = false;
278         }
279     }
280 }