帮忙解决一下这个问题.

[FACCHETTI]

比如我有一个表.
name1 name2 xx 3个列
我的意思是 用2个combobox来绑定 name1 name2的数据,把列内的数据作为combobox的item.

我现在希望是 当选定了 combobox1内的数据,那么combobox2之显示和前面有关联的item,谢谢~~~

[FACCHETTI]

我的意思是先要在combobox把列1的元素先显示出来,才能选择啊
我绑定了,,那一列..
怎么运行就只显示一行呢?下拉也没有用.
能否详细点呢? 很急.,.

[liujia_0421]

for example:

private void Form1_Load(object sender, EventArgs e)
{
DataBind();
}

private void DataBind()
{
SqlConnection con = new SqlConnection("server=.;database=student;uid=sa;pwd=0421");
SqlDataAdapter sda = new SqlDataAdapter("select * from studentDetails", con);
DataSet ds = new DataSet();
sda.Fill(ds, "student");
this.comboBox1.DataSource = ds.Tables["student"];
this.comboBox1.DisplayMember = "sno";
this.comboBox2.DataSource = ds.Tables["student"];
this.comboBox2.DisplayMember = "sname";
this.comboBox2.ValueMember = "sno";
}

[FACCHETTI]

谢谢liujia_0421~`
但是当选定了 combobox1内的数据,那么combobox2之显示和前面有关联的item,谢谢~~~

比如 name1 name2 xx
a b 1
a c 1
b d 1
当我选择了combobox1的 a.. 我希望 combobox2中只显示 b,c
同时我希望 用一个textbox 来显示 combobox1.text 和combobox2.text 对应的那个xx的值.
谢谢

[ericksky]

学习

[liujia_0421]

TO:当我选择了combobox1的 a.. 我希望 combobox2中只显示 b,c
同时我希望 用一个textbox 来显示 combobox1.text 和combobox2.text 对应的那个xx的值.
谢谢


哦，那我把你的意思给理解错了，给你提供个思路吧..我就不帮你写代码了..

private void DataBind()
{
OleDbConnection con = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=d:\student.mdb;");
OleDbDataAdapter sda = new OleDbDataAdapter("select * from studentDetails", con);
DataSet ds = new DataSet();
sda.Fill(ds, "student");
this.comboBox1.DataSource = ds.Tables["student"];
this.comboBox1.DisplayMember = "sno";
//把DataBind中的这几句注释掉..
//this.comboBox2.DataSource = ds.Tables["student"];
//this.comboBox2.DisplayMember = "sname";
//this.comboBox2.ValueMember = "sno";
}

然后再ComboBox的selectedIndexChanged事件下...

以ComboBox1当前选中的Value再查找数据库，将结果绑定到CommboBox2中即可...

[FACCHETTI]

呵呵.谢谢,,好了..
但是textbox怎么和xx这列绑定.
我的意思是 当combobox1 和combobox2选定后,然后 可以定一个xx的值.
OleDbDataAdapter sda = new OleDbDataAdapter("select rates from rates where moneyname1='" + comboBox1.Text + "'&&moneyname2='" + comboBox2.Text + "'", con);

???

[liujia_0421]

取出来后,直接显示在TextBox中不就OK了?

this.TextBox.Text="查询出来的值";

[FACCHETTI]

能详细点吗?
OleDbConnection con = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=rats.mdb;User Id=Admin;Password=;");
OleDbDataAdapter sda = new OleDbDataAdapter("select rates from rates where moneyname1='" + comboBox1.Text + "'and moneyname2='" + comboBox2.Text + "'", con);
DataSet ds = new DataSet();
sda.Fill(ds, "rate");
//this.textBox1.DataBindings.Add("Text", sda, "rates.rates");
// this.textBox1.Text =;


该怎么改,谢谢.

[liujia_0421]

TO:
OleDbDataAdapter sda = new OleDbDataAdapter("select rates from rates where moneyname1='" + comboBox1.Text + "'and moneyname2='" + comboBox2.Text + "'", con);
DataSet ds = new DataSet();
sda.Fill(ds, "rate");
//this.textBox1.DataBindings.Add("Text", sda, "rates.rates");
// this.textBox1.Text =;


这里没有必要再绑定了...
OleDbCommand cmd=new OleDbCommand("你的查询字符串");
//打开连接
con.Open();
OleDbDataReader sdr=cmd .ExecuteReader();
if (sdr.Read())
{
this.TextBox1.Text=Convert.ToString(sdr["rates"]);
}
sdr.Close();
//关闭数据库连接
con.Close();

[FACCHETTI]

我的那个sql语句是不是格式不对?

[FACCHETTI]

报错.

[FACCHETTI]

access的数据库..谢谢,c#不是太熟

[LeoMaya]

在comboBox1_SelectedIndexChanged事件里面, 调用
select comboBox1.SelectedItem.ToString() from name2

又或者用Hashtable将name1当作key, name2中的内容序列号当作Hashtable的value, 然后在comboBox1_SelectedIndexChanged事件里面调用
comboBox2.SelectedIndex = (int)hashtable[(string)comboBox1.SelectedItem];

[liujia_0421]

private void Form1_Load(object sender, EventArgs e)
{
DataBind();
}

private void DataBind()
{
OleDbConnection con = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=d:\student.mdb;");
OleDbDataAdapter sda = new OleDbDataAdapter("select * from studentDetails", con);
DataSet ds = new DataSet();
sda.Fill(ds, "student");
this.comboBox1.DataSource = ds.Tables["student"];
this.comboBox1.DisplayMember = "sno";
this.comboBox2.DataSource = ds.Tables["student"];
this.comboBox2.DisplayMember = "sname";
this.comboBox2.ValueMember = "sno";
}

[liujia_0421]

Don't forget:

using System.Data.OleDb;

[liujia_0421]

你把提示的错误贴出来看下..

[liujia_0421]

用Oracle数据库给你写了个例子,看下:

private void Form1_Load(object sender, EventArgs e)
{
DataBind();
}
private void DataBind()
{
OleDbConnection con = new OleDbConnection("Provider=OraOLEDB.Oracle.1;data source=oracle;user id=****;password=****");
OleDbDataAdapter sda = new OleDbDataAdapter("select * from student", con);
DataSet ds = new DataSet();
sda.Fill(ds, "student");
this.comboBox1.DataSource = ds.Tables["student"];
this.comboBox1.DisplayMember = "sname";
}

private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
OleDbConnection con = new OleDbConnection("Provider=OraOLEDB.Oracle.1;data source=oracle;user id=****;password=****");
if (this.comboBox1.SelectedItem != null)
{
OleDbCommand cmd = new OleDbCommand("select sage from student where sname='" + this.comboBox1.Text + "'", con);
con.Open();
OleDbDataReader sdr = cmd.ExecuteReader();
if (sdr.Read())
{
this.textBox1.Text = Convert.ToString(sdr["sage"]);
}
sdr.Close();
con.Close();
}
}

[FACCHETTI]

谢谢..liujia_0421..
谢谢!!

[FACCHETTI]

..

[FACCHETTI]

OleDbConnection con = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;
Data Source=rats.mdb;User Id=Admin;Password=;");
OleDbCommand cmd = new OleDbCommand("select rates from rates where
moneyname1='" + comboBox1.Text + "'and moneyname2='" + comboBox2.Text + "'");
//打开连接
con.Open();
OleDbDataReader sdr = cmd.ExecuteReader();///报错 Connection 属性尚
未初始化。
if (sdr.Read())
{
this.textBox1.Text = Convert.ToString(sdr["rates"]);
}
sdr.Close();
//关闭数据库连接
con.Close();