处理点击取消清空文本输入，处理数据库报错导致程序崩溃问题。

CNAS_RunSync/ucSynchrousMain.cs

@@ -119,29 +119,39 @@ namespace CNAS_RunSync
             AddDatagridColumn(dgvSyncData, "GridGuid", "GridGuid", 50, false);
 
             //2.2获取数据源数据
-            this.RefreshData();
+            try
+            {
+                this.RefreshData();
+            }
+            catch (Exception exception)
+            {
+                MessageBox.Show($"查询数据时发生异常：{exception.Message}");
+            }
 
             //3.初始化查询相关内容
             //3.1 绑定Combobox数据源        
-            foreach (DataColumn dc in dtSource.Columns)
+            if (0 < dtSource?.Columns?.Count)
             {
-                if (syncInstrumentItem.LstSyncPramas.Where(s => s.SourceField.ToUpper() == dc.ColumnName.ToUpper()).LongCount<SyncParamasInfo>() > 0)
+                foreach (DataColumn dc in dtSource.Columns)
                 {
-                    string strColumnName = dc.ColumnName;
-                    if (DictField.ContainsKey(strColumnName))
-                        strColumnName = DictField[strColumnName];
-                    DictComboBox.Add(strColumnName, dc.DataType);
+                    if (syncInstrumentItem.LstSyncPramas.Where(s => s.SourceField.ToUpper() == dc.ColumnName.ToUpper()).LongCount<SyncParamasInfo>() > 0)
+                    {
+                        string strColumnName = dc.ColumnName;
+                        if (DictField.ContainsKey(strColumnName))
+                            strColumnName = DictField[strColumnName];
+                        DictComboBox.Add(strColumnName, dc.DataType);
+                    }
                 }
-            }
-            if (DictComboBox.Count > 0)
-            {
-                BindingSource bsComboBox = new BindingSource
+                if (DictComboBox.Count > 0)
                 {
-                    DataSource = DictComboBox
-                };
-                cmbColumns.DataSource = bsComboBox;
-                cmbColumns.ValueMember = "Key";
-                cmbColumns.DisplayMember = "Key";
+                    BindingSource bsComboBox = new BindingSource
+                    {
+                        DataSource = DictComboBox
+                    };
+                    cmbColumns.DataSource = bsComboBox;
+                    cmbColumns.ValueMember = "Key";
+                    cmbColumns.DisplayMember = "Key";
+                }
             }
         }
 
@@ -178,7 +188,7 @@ namespace CNAS_RunSync
                 }
                 catch
                 {
-
+                    
                 }
                 dtSource = dv.ToTable();
             }
@@ -574,7 +584,16 @@ namespace CNAS_RunSync
             }
 
             //0.获取数据源数据
-            this.RefreshData();
+            try
+            {
+
+                this.RefreshData();
+            }
+            catch (Exception exception)
+            {
+                MessageBox.Show($"查询数据时发生异常：{exception.Message}");
+                return;
+            }
 
             //1.合法性检测
             if (DictComboBox[cmbColumns.SelectedValue.ToString()].ToString().Equals("System.DateTime"))
@@ -730,6 +749,8 @@ namespace CNAS_RunSync
         }
         private void btnCancelFind_Click(object sender, EventArgs e)
         {
+            this.txtFind.Text = string.Empty;
+
             foreach (DataGridViewRow dgvrow in dgvSyncData.Rows)
             {
                 if (dgvrow.Cells[0].Value != null && dgvrow.Cells[0].Value.ToString() == "True")