this.dataGridView1.DataSource = a

As an AI language model, I do not have access to the context of this code. However, it seems that the code is setting the data source of a DataGridView control called dataGridView1 to a variable called "a".

In general, setting the data source of a DataGridView control allows you to display data from a source such as a database or a collection of objects. The data is then automatically displayed in rows and columns within the grid.