TextBox控件中更改的数据未在表单提交代码中更新。 [英] The changed data from TextBox controls is not getting updated in the form submit code.

问题描述

更新表单数据用于更新数据库中的记录。单击窗体上的btnUpdate后，事件处理程序以调试/跟踪模式显示旧数据，因此旧数据将被存储，而新更改的数据则不会。

帮助程序类DBUtility位于单独的C＃文件和namesapce，已正确导入。



帮助程序类：

The Update form data is used to update the record in data base. Upon clicking the 'btnUpdate' on form, the event handler shows the old data in debug/trace mode, and therefore old data gets stored and new changed data does not.
The helper class DBUtility is in a separate C# file and namesapce, which is properly imported.

Helper Class:

public class DBUtility {
public static Int32 ExecuteNonQuery(string cmdName, CommandType cmdType, params SqlParameter[] pars) {
		using (SqlConnection conn = new SqlConnection(connString)) {
			using (SqlCommand cmd = new SqlCommand(cmdName, conn)) {
				cmd.CommandType = cmdType;
				cmd.CommandText = cmdName;
				if (pars.Length > 0)
					cmd.Parameters.AddRange(pars);

				conn.Open();
				return cmd.ExecuteNonQuery();
 			}
		}
	}
}

问题代码：btnUpdate_Click方法

Problem Code: the btnUpdate_Click method

public partial class InsertStudent : System.Web.UI.Page {
	private int studId;
	protected void Page_Load(object sender, EventArgs e) {
		studId = Int32.Parse(Request.Params.Get("id"));
		DataTable table = DBUtility.ExecuteSelectTable("SELECT * FROM stud_master WHERE StudId = @ID", CommandType.Text, new SqlParameter[] { new SqlParameter("@ID", studId) });

		txtID.Text = table.Rows[0].ItemArray[0].ToString();
		txtFName.Text = table.Rows[0].ItemArray[1].ToString();
		txtLName.Text = table.Rows[0].ItemArray[2].ToString();
		txtEmail.Text = table.Rows[0].ItemArray[3].ToString();
		txtCity.Text = table.Rows[0].ItemArray[4].ToString();

	}

	protected void btnUpdate_Click(object sender, EventArgs e) {		
		string updateCommand = "UPDATE stud_master SET firstName = @Fname, lastName = @Lname, emailId = @Email, city = @City WHERE StudID = @ID";
		SqlParameter[] parameters = new SqlParameter[] {
			new SqlParameter("@ID", txtID.Text),
			new SqlParameter("@Fname", txtFName.Text),
			new SqlParameter("@Lname", txtLName.Text),
			new SqlParameter("@Email", txtEmail.Text),
			new SqlParameter("@City", txtCity.Text)
		};

		DBUtility dbUtility = new DBUtility();
		if (DBUtility.ExecuteNonQuery(updateCommand, CommandType.Text, parameters) > 0) {
			lblStatus.Text = "Record Successfully Updated.";
		}
		else {
			lblStatus.Text = "Cannot add new Record. Operation failed.";
		}
	}
}

当使用Insert表单中的类似代码时，它会被插入。

类似代码没有问题

When similar code in the Insert form is used it gets inserted.
Similar Code with no problem

public partial class InsertStudent : System.Web.UI.Page {
	protected void btnInsert_Click(object sender, EventArgs e) {
		string insertCommand = "INSERT INTO stud_master VALUES(@ID, @Fname, @Lname, @Email, @City)";
		SqlParameter[] parameters = new SqlParameter[] {
			new SqlParameter("@ID", txtID.Text),
			new SqlParameter("@Fname", txtFName.Text),
			new SqlParameter("@Lname", txtLName.Text),
			new SqlParameter("@Email", txtEmail.Text),
			new SqlParameter("@City", txtCity.Text)
		};


		Int32 rowsAffected = DBUtility.ExecuteNonQuery(insertCommand, CommandType.Text, parameters);
		if (rowsAffected > 0) {
			lblStatus.Text = "Record Successfully added.";
		}
		else {
			lblStatus.Text = "Cannot add new Record. Operation failed.";
		}
	}
}

推荐答案

问题是，因为我发现页面加载事件在btnUpdate事件之前触发。在前者我放置代码来初始化我的文本字段WITHOUT CHECKING如果它是回发！当应用该检查时问题已解决。

感谢您的帮助和关注。

The problem was, as I discovered that the page load event was firing before the btnUpdate event. In the former I placed the code to initialize my text fields WITHOUT CHECKING if it is a postback! When that check was applied the problem resolved.
Thank you both for help and concern.

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