linq中怎么解决这个问题:Cannot add an entity with a key that is already in use.
错误信息：Cannot add an entity with a key that is already in use.
错误源：App_Web_vvfzwtzj
堆栈跟踪： 在 UserManagerUC.imgBtnSubmit_Click(Object sender, ImageClickEventArgs e) 位置 d:\MyWork\IM\Controls\UserManagerUC.ascx.cs:行号 361
C# code
protected void imgBtnSubmit_Click(object sender, ImageClickEventArgs e)
{
this.DoInit();
try
{
DBIMDataContext IM = (DBIMDataContext)Application["IM"];
try
{
var users = from user in IM.Users
where user.userID == this.txtUserID.Text
select user;
if (users.Count<User>()>0)
{
this.lblFailed.Text = "This user has been existed!";
this.lblFailed.Visible = true;
return;
}
if (string.IsNullOrEmpty(this.txtAddress.Text))
{
this.lblFailed.Visible = true;
this.lblFailed.Text = "Address is empty!";
}
else if (string.IsNullOrEmpty(this.txtCompany.Text))
{
this.lblFailed.Visible = true;
this.lblFailed.Text = "Company is empty!";
}
else if (string.IsNullOrEmpty(this.txtEmail.Text))
{
this.lblFailed.Visible = true;
this.lblFailed.Text = "Email is empty!";
}
else if (string.IsNullOrEmpty(this.txtPassword.Text))
{
this.lblFailed.Visible = true;
this.lblFailed.Text = "Password is empty!";
}
else if (string.IsNullOrEmpty(this.txtTelphone.Text))
{
this.lblFailed.Visible = true;
this.lblFailed.Text = "Telphone is empty!";
}
else
{
User xUser = new User();
xUser.userID = this.txtUserID.Text;
xUser.address = this.txtAddress.Text;
xUser.company = this.txtCompany.Text;
xUser.email = this.txtEmail.Text;
if (string.IsNullOrEmpty(this.txtNickName.Text))
{
xUser.nickName = this.txtUserID.Text;
}
else
{
xUser.nickName = this.txtNickName.Text;
}
xUser.orderFlag = int.Parse(this.ddlOrderFlag.SelectedValue);
xUser.password = this.txtPassword.Text;
xUser.roleID = this.rblRoles.SelectedValue;
xUser.telphone = this.txtTelphone.Text;
IM.Users.InsertOnSubmit(xUser);
IM.SubmitChanges();
this.divList.Visible = true;
this.BindGVUsers();
}
}
catch (Exception exception)
{
throw exception;
}
}
catch (Exception exception)
{
try
{
//发送错误信息给管理员
MyMail mail = new MyMail();
mail.Send(exception);
this.lblFailed.Visible = true;
this.lblFailed.Text = exception.Message;
}
catch (Exception ex)
{
this.lblFailed.Visible = true;
this.lblFailed.Text = ex.Message;
}
}
}
[解决办法]
xUser.userID = this.txtUserID.Text;
userID 是主键吧？应该是两次输入的txtUserID.Text重复了
[解决办法]
if (string.IsNullOrEmpty(this.txtNickName.Text))
{
xUser.nickName = this.txtUserID.Text;
}
else
{
xUser.nickName = this.txtNickName.Text;
}
这里存在问题，二次赋值。
你可以用一个临时变量来过渡
试试
string temp=xUser.nickName = this.txtNickName.Text;
if (string.IsNullOrEmpty(this.txtNickName.Text)) {temp=this.txtUserID.Text; }
xUser.nickName = temp;
[解决办法]
- C# code
string temp= string.IsNullOrEmpty(this.txtNickName.Text)?this.txtUserID.Text:this.txtNickName.Text;xUser.nickName = temp;