是否可以在列数据类型为double的列中插入空值?

本文关键字：插入 空值 double 数据类型 是否 | 更新日期: 2023-09-27 18:17:00

     `enter code here`
                private void btnSave_Click(object sender, RoutedEventArgs e)
                            {
                         GRepository<tblDEIPO_Primary> GR = new GRepository<tblDEIPO_Primary>();
                                    tblDEIPO_Primary objDIE = new tblDEIPO_Primary();
                                    if (txtid.Text == "")
                                    {
                                        objDIE.DIEPONo = txtDIEPO.Text;
                                        objDIE.PoDate = dtpDeiPoDate.Text;
                                        objDIE.Vendor = cmbVendor.Text;
                                        objDIE.Remark = txtRemark.Text;
                                        objDIE.TermsAndConditions = txtTermsAndCondition.Text;
                                        objDIE.TaxType = cmbTaxtype.Text;
                                        objDIE.Tax = Convert.ToDouble(txtTax.Text);
                                        objDIE.TaxAmount = Convert.ToDouble(txtTaxAmount.Text);
                                        objDIE.BonusPenalty = s;
                                        if (chkBonus.IsChecked == true)
                                        {
                                            objDIE.BonusPenaltyAmount = Convert.ToDouble(txtBonus.Text);
                                        }
                                        else if (chkPenalty.IsChecked == true)
                                        {
                                            objDIE.BonusPenaltyAmount = Convert.ToDouble(txtPenalty.Text);
                                        }
                                        objDIE.DeiType = cmbDieType.Text;
                                        objDIE.TypeofInjections = cmbTypeOfInjection.Text;
                                        objDIE.Total =Convert.ToDouble( txtTotal.Text);
                                        objDIE.TotalAmount =Convert.ToDouble(txtAmount.Text);
                                        GR.Insert(objDIE);
                                        GR.Save();}

当我点击btnSave_Click按钮时，时间错误产生"输入字符串格式不正确。"在objDIE。Tax = Convert.ToDouble(txtax . text);因为我正在这个文本框中插入空白值，所以请提供解决方案。

                    > Blockquote

是否可以在列数据类型为double的列中插入空值?

所以使用double.TryParse 

double taxAmount= 0;
objDIE.TaxAmount = double.TryParse(txtTaxAmount.Text, out taxAmount) ? taxAmount: DbNull.Value;

您可以使用double.TryParse来测试您的输入值是否为double。

可以替换为:

objDIE.TaxAmount = Convert.ToDouble(txtTaxAmount.Text);


double num;
bool res = double.TryParse(txtTax.Text, out num);
if (res)
{
    // String is a double.
    objDIE.TaxAmount = num;
}
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