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Combobox anotherform: Cannot bind to the new display member.

sokran960 asked:

Open original thread
Hi. I'm quite new for c++/cli. I tried to make a ComboBox1 on Form2 which ComboBox1 Bind to MySql Database Table.

Form2 Code
            DTab2 = gcnew DataTable();
            this->comboBox1->DataSource = DTab2->DefaultView;
            this->comboBox1->DisplayMember = "Name";
            this->comboBox1->ValueMember = "ID";
    public:property DataTable ^CB_Prop
               void set(DataTable ^value){
                    DTab2 = value;}
               DataTable ^get(){
                    return DTab2;}
        /// Required designer variable.
        DataTable ^DTab2;

Form1 Code
#include "Form2.h"
                _Form2 = gcnew Form2();
		String ^ConnString = "server=localhost;user=root;database=MyDB; "
		MySqlConnection ^Conn = gcnew MySqlConnection(ConnString);
		MySqlDataAdapter ^MyAdapt = gcnew MySqlDataAdapter();
		MyAdapt->SelectCommand = gcnew MySqlCommand("SELECT ID, Name FROM "
                                         "MyTable", Conn);
            DataTable ^DTab1 = gcnew DataTable();
		_Form2->CB_Prop = DTab1;
		/// Required designer variable.
		Form2 ^_Form2;
private: System::Void button1_Click(System::Object^  sender, System::EventArgs^  e) {

The code was Build succeeded but I got error
"An unhandled exception of type 'System.ArgumentException' occurred in System.Windows.Forms.dll"
"Additional information: Cannot bind to the new display member"

I tried to replace

this->comboBox1->ValueMember = "ID";

Form1 and Form2 succeeded initialize but there no items in Combobox1.

I make modification on Form 2 and decide not using DataTable instead DataSet. So I replace DataTable at Form1 and Form2 With DataSet with addition MySqlDataAdapter at Form2
            String^ ConnString2 = "server=localhost;user=root;database=MyDB; "
            MySqlConnection ^Conn2 = gcnew MySqlConnection(ConnString2);
            MySqlDataAdapter^ MyAdt2 = gcnew MySqlDataAdapter("SELECT ID, Name "
                            "FROM MyTable", Conn2);
            DSet2 = gcnew System::Data::DataSet();
            MyAdt2->Fill(DSet2, "MyTable");
            this->comboBox1->DataSource = DSet->Tables["MyTable"];
            this->comboBox1->DisplayMember = "Name";
            this->comboBox1->ValueMember = "ID";
    public:property DataSet ^CB_Prop
               void set(DataSet ^value) {
                   DSet2 = value;}
               DataSet ^get() {
                   return DTab2;}

It work and the ComboBox1 filled correctly. But I don't know it's the good way or not.
Tags: Windows, Forms


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