//删除该节点以及他的子节点
protected void Button4_Click(object sender, EventArgs e)
{
string id = this.TreeView1.SelectedValue.ToString(); if (TreeView1.SelectedNode.ChildNodes.Count == 0)
{ string sql = "delete from Tab_System_Area where AreaId=" + id; SqlCommand cmd = new SqlCommand(sql, conn); if (conn.State == ConnectionState.Closed)
{ conn.Open(); } int n = 0; n = cmd.ExecuteNonQuery(); conn.Close(); if (n > 0)
{ TreeView1.Nodes.Clear(); CreateNode("0", (TreeNode)null); Page.ClientScript.RegisterStartupScript( typeof(string), "1", "<script>alert('删除成功!')</script>");
} }
else this.Label1.Text = "当前节点有子节点不能被删除,请先删除其子节点再执行此操作!";
}上边的代码 大侠看下 . 能删除,数据库也更新. 不过不会提示消息框 还有就是 我是判断如果没有子节点才能被删除.有的话就会谈出提示.并且不能删除,但是不会谈出提示. 而且出错: 未将对象引用设置到对象的实例!大侠指点 急急急!!!!!!!!
protected void Button4_Click(object sender, EventArgs e)
{
string id = this.TreeView1.SelectedValue.ToString(); if (TreeView1.SelectedNode.ChildNodes.Count == 0)
{ string sql = "delete from Tab_System_Area where AreaId=" + id; SqlCommand cmd = new SqlCommand(sql, conn); if (conn.State == ConnectionState.Closed)
{ conn.Open(); } int n = 0; n = cmd.ExecuteNonQuery(); conn.Close(); if (n > 0)
{ TreeView1.Nodes.Clear(); CreateNode("0", (TreeNode)null); Page.ClientScript.RegisterStartupScript( typeof(string), "1", "<script>alert('删除成功!')</script>");
} }
else this.Label1.Text = "当前节点有子节点不能被删除,请先删除其子节点再执行此操作!";
}上边的代码 大侠看下 . 能删除,数据库也更新. 不过不会提示消息框 还有就是 我是判断如果没有子节点才能被删除.有的话就会谈出提示.并且不能删除,但是不会谈出提示. 而且出错: 未将对象引用设置到对象的实例!大侠指点 急急急!!!!!!!!
是没有问题的.
但是你前面的代码都执行了吗?
protected void Button4_Click(object sender, EventArgs e)
{
if(this.TreeView1.SelectedIndex !=-1)
{
string id = this.TreeView1.SelectedValue.ToString(); if (TreeView1.SelectedNode.ChildNodes.Count == 0)
{ string sql = "delete from Tab_System_Area where AreaId=" + id; SqlCommand cmd = new SqlCommand(sql, conn); if (conn.State == ConnectionState.Closed)
{ conn.Open(); } int n = 0; n = cmd.ExecuteNonQuery(); conn.Close(); if (n > 0)
{
Response.Write(" <script>alert('删除成功!') </script>");
}
}
else
{
Response.Write(" <script>alert('当前节点有子节点不能被删除,请先删除其子节点再执行此操作!') </script>");
}
}
}