C＃：如何获取未绑定的DataGridView单元的值？

Question

I'm fairly newbie at C#. I've seen questions answering how to set values in an unbound grid. Which seems to work. But, to get the value back out doesn't seem to. I did try searching for the answer.

I have an unbound DataGridView, named analogGrid. Data is stored in an external class RTUdata. It is a very simple grid, first column is read only with the row number. Second value is a value the user can change which should store it back into RTUdata. Loading the data into the grid seems to work fine with this method:

private void loadAnalog()
{
    analogGrid.RowCount = RTUdata.getAnalogCount(RTUdata.getRTUaddr());
    for (UInt16 i = 0; i < RTUdata.getAnalogCount(RTUdata.getRTUaddr()); i++)
    {
        analogGrid.Rows[i].Cells[0].ValueType = typeof(System.UInt16);
        analogGrid.Rows[i].Cells[0].Value = i;
        analogGrid.Rows[i].Cells[1].ValueType = typeof(System.Int32);
        analogGrid.Rows[i].Cells[1].Value = RTUdata.getAnalogValue(RTUdata.getRTUaddr(), i);
    }
}

I'm not quite certain which event I should hook into as far as when to grab the value that the user entered and put it back into RTUdata. But, I'm guessing it would be CellValidated(). So, I have this code:

private void analogGrid_CellValidated(object sender, DataGridViewCellEventArgs e)
{
    if (e.ColumnIndex != 1)
        return;

    Int32 value = (Int32)binaryGrid.Rows[e.RowIndex].Cells[e.ColumnIndex].Value;
    RTUdata.setAnalogValue(RTUdata.getRTUaddr(), e.RowIndex, value);        
}

But, on the line

Int32 value = (Int32)binaryGrid.Rows[e.RowIndex].Cells[e.ColumnIndex].Value;

I get a runtime error of "System.InvalidCastException: 'Specified cast is not valid.'" As far as I can tell, "Value" should be Int32, I set the value type when I load the grid. So, why isn't the cast valid?

Thanks for any help!

Answer 1

You're probably trying to cast a string value to int, which won't work. Instead, convert it with .ToString() .

Try this:

Int32 value = Int32.Parse(binaryGrid.Rows[e.RowIndex].Cells[e.ColumnIndex].Value.ToString());