C# · 12月 23, 2021

c# – 解决“不包含’OfType’的定义”错误消息?

这是我的代码并出现未知错误: private void dataGridView1_CellValueChanged(object sender,DataGridViewCellEventArgs e){ for (int i = 0; i < dataGridView1.Rows.Count; ++i) { object a = dataGridView1.Rows[i].Cells[“price”].Value; object b = dataGridView1.Rows[i].Cells[“tedad”].Value; double aNumber = 0; double bNumber = 0; if (a != null) aNumber = Double.Parse(a.ToString()); if (b != null) bNumber = Double.Parse(b.ToString()); dataGridView1.Rows[i].Cells[“total”].Value = aNumber * bNumber; dataGridView1.RefreshEdit(); } decimal sum = dataGridView1.Rows.OfType<DataGridViewRow>() .Sum(row => Convert.ToDecimal(row.Cells[“total”].Value)); txtDate.Text = sum.ToString();

像OfType()这样的错误:

‘System.Windows.Forms.DataGridViewRowCollection’ does not contain a deFinition for ‘OfType’ and no extension method ‘OfType’ accepting a first argument of type ‘System.Windows.Forms.DataGridViewRowCollection’ WindowsFormsApplication1test

解决方法 确保你有: using System.Linq;

Enumerable.OfType Method

>命名空间:System.Linq>程序集:System.Core(在System.Core.dll中)