I neeed Solution for Error :Unable to cast object of type 'system.int32' to type 'system.byte[]'.

Question

i design desktop application for Customer
i coding Edit Form
My Error is
Unable to cast object of type 'System.Int32' to type 'System.Byte[]'.
i clicked f10 to debug my Application
My Error Here
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C#
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byte[] pa_img = (byte[])Customer_Function.Customer_Operation.Show_Customer_Image(Convert.ToInt32(this.dataGridView_ShowData.CurrentRow.Cells[0].Value )).Rows[0][0]; my Error Here

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Error Is
Unable to cast object of type 'System.Int32' to type 'System.Byte[]'.

What I have tried:

C#
Copy Code
private void btn_Edit_Click(object sender, EventArgs e)
{
Add_New_FORM add_New_FORM = new Add_New_FORM();
add_New_FORM.btn_Add.Visible = false;
add_New_FORM.btn_Delete.Visible = false;

        add_New_FORM.ID_TextBox.Text = this.dataGridView_ShowData.CurrentRow.Cells[0].Value.ToString();
        add_New_FORM.Name_TextBox.Text = this.dataGridView_ShowData.CurrentRow.Cells[1].Value.ToString();
        add_New_FORM.phone_TextBox.Text = this.dataGridView_ShowData.CurrentRow.Cells[2].Value.ToString();
        add_New_FORM.kind_TextBox.Text = this.dataGridView_ShowData.CurrentRow.Cells[3].Value.ToString();
        add_New_FORM.textBox4.Text = this.dataGridView_ShowData.CurrentRow.Cells[4].Value.ToString();
        add_New_FORM.FirstDate_TextBox.Text = this.dataGridView_ShowData.CurrentRow.Cells[5].Value.ToString();
        add_New_FORM.End_Date.Text = this.dataGridView_ShowData.CurrentRow.Cells[6].Value.ToString();
        add_New_FORM.Cost_TextBox.Text = this.dataGridView_ShowData.CurrentRow.Cells[7].Value.ToString();
        add_New_FORM.Paid_TextBox.Text = this.dataGridView_ShowData.CurrentRow.Cells[8].Value.ToString();
        add_New_FORM.remain_TextBox.Text = this.dataGridView_ShowData.CurrentRow.Cells[9].Value.ToString();
        add_New_FORM.NotesAboutTRAINING_TextBox.Text = this.dataGridView_ShowData.CurrentRow.Cells[10].Value.ToString();

byte[] pa_img = (byte[])Customer_Function.Customer_Operation.Show_Customer_Image(Convert.ToInt32(this.dataGridView_ShowData.CurrentRow.Cells[0].Value )).Rows[0][0];
MemoryStream ms = new MemoryStream(pa_img);
add_New_FORM.pictureBox_ForTRAINER.Image = Image.FromStream(ms);
add_New_FORM.ShowDialog();
}

Answer 1

It's much better to load data using the DataGridView.DataSource.

Example, the following loads a DataTable with data where Picture is a Byte array when loaded into the DataTable.

public static DataTable GetCategories()  
{  
  
    DataTable table = new DataTable();  
    using (var cn = new SqlConnection(_connectionString))  
    {  
        using (var cmd = new SqlCommand() { Connection = cn })  
        {  
            cmd.CommandText = "SELECT CategoryID, CategoryName, Picture FROM dbo.Categories";  
            cn.Open();  
            table.Load(cmd.ExecuteReader());  
            table.Columns["CategoryID"].ColumnMapping = MappingType.Hidden;  
        }  
    }  
  
    return table;  
}  

In the form, create a BindingSource, set its DataSource to the method above.

private readonly BindingSource bindingSource = new BindingSource();  
public DataGridViewWithImageForm()  
{  
    InitializeComponent();  
    Shown += OnShown;  
}  
  
private void OnShown(object sender, EventArgs e)  
{  
    bindingSource.DataSource = DataOperations.GetCategories();  
    dataGridView1.DataSource = bindingSource;  
}  

Now to get at the current row's image.

byte[] imageArray = ((DataRowView)bindingSource.Current).Row.Field<byte[]>("Picture");  

You'll know it works by executing the code but let's show the current image in a picturebox.

byte[] imageArray = ((DataRowView)bindingSource.Current).Row.Field<byte[]>("Picture");  
  
ImageConverter converter = new ImageConverter();  
pictureBox1.Image = (Image)converter.ConvertFrom(imageArray);