(回帖给分)在将 varchar 值 转换成数据类型 int 时失败。
在将 varchar 值 'System.Web.UI.HtmlControls.HtmlInputText' 转换成数据类型 int 时失败。

我用datalist写了一个添加的代码

数据表里有字段



在一个表格中添加产品的代码是


protected void btnNew_Click(object sender, ImageClickEventArgs e)
{
DBconn DB = new DBconn();
string strSql = "insert into book (bookname,typeid,write,chubanshename,bookprice,xiancunnumber) values('" + txtBookName.Value + "','" + ddlType.Text + "','" + txtWrite + "','" + txtChuban.Value + "','" + txtBookPrice + "'," +txtBookCount.Value + ")";
DB.ExecuteNonQuery(strSql);
btnNew.Visible = false;
Panel1.Visible = false;
DataList1.Visible = true;
DataBindDataList();
initTable();

}


DBconn.cs文件 用于连接。。倒数第二句话 cmd.ExecuteNonQuery(); 报错 说 在将 varchar 值 'System.Web.UI.HtmlControls.HtmlInputText' 转换成数据类型 int 时失败。



public class DBconn
{
private string strConn;
private SqlConnection con;
private SqlCommand cmd;
private SqlDataAdapter sda;
private DataSet ds;




public DBconn()
{
strConn = CreateConnn();
con = new SqlConnection(strConn);
cmd = new SqlCommand();
sda = new SqlDataAdapter();
ds = new DataSet();


}

public string CreateConnn() {
return ConfigurationManager.ConnectionStrings["libraryConnectionString"].ConnectionString;
}
public DataSet Getds(string StrSql) {
con.Open();
sda = new SqlDataAdapter(StrSql, con);
sda.Fill(ds);
con.Close();
return ds;
}

public void ExecuteNonQuery(string strSql) {
con.Open();
cmd.CommandText = strSql;
cmd.Connection = con;
cmd.ExecuteNonQuery();
con.Close();

}

}






[解决办法]
string strSql = "insert into book (bookname,typeid,write,chubanshename,bookprice,xiancunnumber) values('" + txtBookName.Value + "','" + ddlType.Text + "','" + txtWrite + "','" + txtChuban.Value + "','" + txtBookPrice + "'," +txtBookCount.Value + ")";
红的部分对应你数据库字段都是整型，也要进行类型转换

改成这样试试(先判断这些值ddlType.Text不为空)

string strSql = "insert into book (bookname,typeid,write,chubanshename,bookprice,xiancunnumber) values('" + txtBookName.Value + "','" + Convert.ToInt32(ddlType.SelectedValue.Trim()) + "','" + txtWrite + "','" + txtChuban.Value + "','" + Convert.ToInt32(txtBookPrice.Value.Trim()) + "'," +Convert.ToInt32(txtBookCount.Value.Trim()) + ")";
[解决办法]
1楼正解。从页面读到的数字是string类型的，要强制转换一下，用int.Parse()也可以
[解决办法]
string类型转换成int类型 使用int.Parse()
[解决办法]
你的bookprice把不是int类型吗？
[解决办法]
int.tryparse一下
[解决办法]

探讨

string strSql = "insert into book (bookname,typeid,write,chubanshename,bookprice,xiancunnumber) values('" + txtBookName.Value + "','" + ddlType.Text + "','" + txtWrite + "','" + txtChuban.Value + "','……

[解决办法]
先检查一下你输入的是不是int型
[解决办法]
string strSql = "insert into book (bookname,typeid,write,chubanshename,bookprice,xiancunnumber) values('" + txtBookName.Value + "','" + ddlType.Text + "','" + txtWrite + "','" + txtChuban.Value + "','" + txtBookPrice + "'," +txtBookCount.Value + ")";

是你 写错了吧 txtWrite是控件的ID把
string strSql = "insert into book (bookname,typeid,write,chubanshename,bookprice,xiancunnumber) values('" + txtBookName.Value + "','" + ddlType.Text + "','" + txtWrite.Value+ "','" + txtChuban.Value + "','" + txtBookPrice.Value + "'," +txtBookCount.Value + ")";

[解决办法]

string strSql = "insert into book (bookname,typeid,write,chubanshename,bookprice,xiancunnumber) values('" + txtBookName.Value + "'," + ddlType.Text + ",'" + txtWrite + "','" + txtChuban.Value + "'," + txtBookPrice + "," +txtBookCount.Value + ")";

首先你要检查下输入的数据是否是数值类型，然后把sql语句改成上面的再试下，
[解决办法]
先对输入的数据进行判断，包括非法值的判断如输入的不是数字

C# code

 private static int ConvertStringToInteger(string s)        {            int result = 0;            int.TryParse(s, out result);            return result;        }