从数据网格视图中选择多行并以逗号分隔的字符串格式添加到变量 C#

Question

Trying to create a comma separated string based on the values the user selects on the data gridview. This is a windows form application. The data grid view is called 'gvModelsToDelete' and currently I have the below code: ModelName in the code is the column I am after and consists of countries. Eg user selects second row ('UK') and fourth row ('US'). I want the first column of the grid view to be concatenated to a string eg 'UK,US'. If user then selects 'EU' as well. I expect the string to be: 'UK,US,EU'.

private void Delete_Click(object sender, System.EventArgs e)
{
    if (gvModelsToDelete.SelectedRows.Count != 0)
    {
        DataGridViewRow row = this.gvModelsToDelete.SelectedRows[0];
        modelName = row.Cells["MODEL_NAME"].Value.ToString();
    }
}

I need it as a comma-separated string, so I can parse it to a sql stored procedure! Right now it's only accepting one value so even if I select two, it takes the first one I have selected. How can I change the above code to loop through each selected row and concatenate into a string variable so I can use it to parse in as a parameter?

Answer 1

You just need to iterate through the selected rows:

private void Delete_Click(object sender, System.EventArgs e)
{
    if (gvModelsToDelete.SelectedRows.Count > 0)
    {
        modelName = "";
        foreach (DataGridViewRow row in gvModelsToDelete.SelectedRows)
        {
            if (string.IsNullOrEmpty(modelName)
            {
                modelName = row.Cells["MODEL_NAME"].Value.ToString();
            }
            else
            {
                modelName+= "," + row.Cells["MODEL_NAME"].Value.ToString();
            }
        }
    }
}

If you want to use LINQ and have something a little more terse, you can do this:

private void Delete_Click(object sender, System.EventArgs e)
{
    if (gvModelsToDelete.SelectedRows.Count > 0)
    {
        modelName = String.Join(",", 
            from row in gvModelsToDelete.SelectedRowsRows.Cast<DataGridViewRow>
            select row.Cells["MODEL_NAME"].Value.ToString();
        }
    }
}