C#的添加与删除问题!!!
我写咯一个简单的投票系统,可是在我新添加一个用户名后在马上在删除控件中去删除新添加的这个用户就删除不了,但能删除以前的用户,新添加的这个用户写入咯数据库中的!
这是为什么??
这是删除代码:
private void button5_Click(object sender, EventArgs e)
{
ds = link.relateData("select * from piaoshu");
for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
{
dr = ds.Tables[0].Rows[i];
if(dr[0].ToString()==this.comboBox1.Text )
dr.Delete();
this.label4.Text = this.comboBox1.Text + "删除成功!";
}
link.updatedata(ds);
checkedListBox1.Items.Clear ();
textBox2.Text = "";
ds = link.relateData("select * from piaoshu");
for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
{
dr = ds.Tables[0].Rows[i];
this.textBox2.Text += "姓名:" + dr[0].ToString() + "票数:" + dr[1].ToString() + "\r\n";
this.checkedListBox1.Items.Add(dr[0].ToString());
}
}
这是添加代码:
private void button2_Click(object sender, EventArgs e)
{
if (this.textBox1.Text == "")
{
MessageBox.Show("名字不能为空!");
}
else
{
this.comboBox1.Items.Add(textBox1.Text);
ds = link.relateData("select * from piaoshu");
string name = this.textBox1.Text;
DataRow dr = ds.Tables[0].NewRow();
dr[0] = name;
dr[1] = 0;
ds.Tables[0].Rows.Add(dr);
try
{
link.updatedata(ds);
this.label2.Text = name + "添加成功!";
this.textBox2.Text = "";
for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
{
dr = ds.Tables[0].Rows[i];
this.textBox2.Text += "姓名:" + dr[0].ToString() + "票数:" + dr[1].ToString() + "\r\n";
}
this.checkedListBox1.Items.Add(textBox1.Text);
}
catch
{
MessageBox.Show(name + "以在候选人名列中!");
this.textBox1.Text = "";
}
}
}
谢谢~!