diff --git a/Bin/net40/SunnyUI.dll b/Bin/net40/SunnyUI.dll
index 4d61878c..7397284b 100644
Binary files a/Bin/net40/SunnyUI.dll and b/Bin/net40/SunnyUI.dll differ
diff --git a/SunnyUI.Demo/Bin/SunnyUI.Demo.exe b/SunnyUI.Demo/Bin/SunnyUI.Demo.exe
index 35c76bb2..bfd59048 100644
Binary files a/SunnyUI.Demo/Bin/SunnyUI.Demo.exe and b/SunnyUI.Demo/Bin/SunnyUI.Demo.exe differ
diff --git a/SunnyUI.Demo/Controls/FCombobox.cs b/SunnyUI.Demo/Controls/FCombobox.cs
index 8646dbb1..81609a5f 100644
--- a/SunnyUI.Demo/Controls/FCombobox.cs
+++ b/SunnyUI.Demo/Controls/FCombobox.cs
@@ -108,14 +108,21 @@ namespace Sunny.UI.Demo
 
         private void uiComboDataGridView1_ValueChanged(object sender, object value)
         {
-            if (value is DataGridViewRow)
+            if (value == null)
             {
-                DataGridViewRow row = (DataGridViewRow)value;
-                uiComboDataGridView1.Text = row.Cells["Column1"].Value.ToString();
+                uiComboDataGridView1.Text = "";
             }
             else
             {
-                uiComboDataGridView1.Text = "";
+                if (value is DataGridViewRow)
+                {
+                    DataGridViewRow row = (DataGridViewRow)value;
+                    uiComboDataGridView1.Text = row.Cells["Column1"].Value.ToString();
+                }
+                else
+                {
+                    uiComboDataGridView1.Text = "";
+                }
             }
         }
 
diff --git a/SunnyUI/Controls/DropItem/UIComboDataGridViewItem.cs b/SunnyUI/Controls/DropItem/UIComboDataGridViewItem.cs
index f765f75e..762290eb 100644
--- a/SunnyUI/Controls/DropItem/UIComboDataGridViewItem.cs
+++ b/SunnyUI/Controls/DropItem/UIComboDataGridViewItem.cs
@@ -295,7 +295,7 @@ namespace Sunny.UI
             if (dataGridView.RowCount > 0 && dataGridView.SelectedIndex >= 0)
             {
                 if (ShowFilter)
-                    DoValueChanged(this, dataGridView.SelectedRows[0]);
+                    DoValueChanged(this, dataGridView.SelectedRows.Count>0 ? dataGridView.SelectedRows[0] : null);
                 else
                     DoValueChanged(this, dataGridView.SelectedIndex);
             }