我不想只在C＃中的文本框中输入空格，而是在空格中输入charector。这是我的错误代码。

本文介绍了我不想只在C＃中的文本框中输入空格，而是在空格中输入charector。这是我的错误代码。的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

private void btnsave_Click（object sender，EventArgs e） { if（comboslm.Text ==） { MessageBox.Show（请选择推销员名称）; comboslm.Focus（）; } 否则if（slmname.Text ==|| slmname.Text ==！char.IsWhiteSpace（e.KeyChar）） （这里只有红线显示。也无法渲染。） { MessageBox.Show（空的推销员名称不被接受）; slmname.Focus（）; } else if（combosmancode.Text ==） { MessageBox.Show（Select Record Key Number）; combosmancode.Focus（）; } else { SqlConnection con = new SqlConnection（@Data Source = M2\SQL2016; Initial Catalog = inventoryDB; Integrated Security = True）; con.Open（）; SqlCommand cmd = new SqlCommand（UPDATE smanDB SET smaname = @ label2 WHERE smancode = @ label4，con）; cmd.Parameters.Add（@ label2，slmname.Text）; cmd.Parameters.Add（@ label4，combosmancode.GetItemText（combosmancode.SelectedItem））; cmd.ExecuteNonQuery（）; con.Close（）; MessageBox.Show（已成功更新）; / * combosmancode.SelectedIndex = -1; comboslm.SelectedIndex = -1; slmname.Text =; comboslm.Focus（）; * / con = new SqlConnection（@Data Source = M2\SQL2016; Initial Catalog = inventoryDB; Integrated Security = True）; con.Open（）; string query =SELECT smaname FROM smanDB; string que =SELECT smancode FROM smanDB; SqlDataAdapter da = new SqlDataAdapter（query，con）; SqlDataAdapter sda = new SqlDataAdapter（que，con）; DataSet ds = new DataSet（）; DataSet sds = new DataSet（）; da.Fill（ds，smanDB）; sda.Fill（sds，smanDB）; comboslm.DisplayMember =smaname; comboslm.ValueMember =smaname; comboslm.DataSource = ds.Tables [smanDB]; combosmancode.DisplayMember =smancode; combosmancode.ValueMember =smancode; combosmancode.DataSource = sds.Tables [smanDB]; combosmancode.SelectedIndex = -1; comboslm.SelectedIndex = -1; slmname.Text =; con.Close（）;

我的尝试： 我试图检查空。我成功了。但是对于空格只有它显示错误。有空格的charector也行。但是只防止显示错误的空格

解决方案

else if （slmname.Text == || slmname .Text ==！char.IsWhiteSpace（e.KeyChar））

该声明的后半部分是错误的。您无法将文本字段（ slmname.Text ）与布尔值（！char.IsWhiteSpace（e.KeyChar））。

private void btnsave_Click(object sender, EventArgs e) { if(comboslm.Text == "") { MessageBox.Show("Please Select Salesman Name"); comboslm.Focus(); } else if(slmname.Text=="" || slmname.Text==!char.IsWhiteSpace(e.KeyChar)) (Here only redline it is showing.So unable to render also) { MessageBox.Show("Empty Salesman Name Not Accepted"); slmname.Focus(); } else if (combosmancode.Text == "") { MessageBox.Show("Select Record Key Number"); combosmancode.Focus(); } else { SqlConnection con = new SqlConnection(@"Data Source=M2\SQL2016;Initial Catalog=inventoryDB;Integrated Security=True"); con.Open(); SqlCommand cmd = new SqlCommand("UPDATE smanDB SET smaname=@label2 WHERE smancode=@label4", con); cmd.Parameters.Add("@label2", slmname.Text); cmd.Parameters.Add("@label4", combosmancode.GetItemText(combosmancode.SelectedItem)); cmd.ExecuteNonQuery(); con.Close(); MessageBox.Show("Updated Successfully"); /* combosmancode.SelectedIndex = -1; comboslm.SelectedIndex = -1; slmname.Text = ""; comboslm.Focus();*/ con = new SqlConnection(@"Data Source=M2\SQL2016;Initial Catalog=inventoryDB;Integrated Security=True"); con.Open(); string query = "SELECT smaname FROM smanDB"; string que = "SELECT smancode FROM smanDB"; SqlDataAdapter da = new SqlDataAdapter(query, con); SqlDataAdapter sda = new SqlDataAdapter(que, con); DataSet ds = new DataSet(); DataSet sds = new DataSet(); da.Fill(ds, "smanDB"); sda.Fill(sds, "smanDB"); comboslm.DisplayMember = "smaname"; comboslm.ValueMember = "smaname"; comboslm.DataSource = ds.Tables["smanDB"]; combosmancode.DisplayMember = "smancode"; combosmancode.ValueMember = "smancode"; combosmancode.DataSource = sds.Tables["smanDB"]; combosmancode.SelectedIndex = -1; comboslm.SelectedIndex = -1; slmname.Text = ""; con.Close();

What I have tried: I tried to check empty. I succeeded. But for spaces only then it showing error. charector with spaces also ok. But prevent only spaces showing error

解决方案

else if(slmname.Text=="" || slmname.Text==!char.IsWhiteSpace(e.KeyChar))

The second half of that statement is wrong. You cannot compare a text field (slmname.Text) to a boolean value (!char.IsWhiteSpace(e.KeyChar)).