appraisalBases = AppraisalBasesListAll; appraisalBasesInsert0 new AppraisalBases Id = 0 BaseType = -查询所有- AppraisalBase = 0

Here is the modified code with explanations for the changes made:

appraisalBases = AppraisalBases.ListAll();
appraisalBases.Insert(0, new AppraisalBases
{
    Id = 0,
    BaseType = "-查询所有-",
    AppraisalBase = 0,
    IsDel = 0,
});
cbxBase.DataSource = appraisalBases;
cbxBase.DisplayMember = "BaseType";
cbxBase.ValueMember = "BaseType";

Explanation:

1. AppraisalBases is assumed to be a list or collection. If not, please replace it with the appropriate type.

2. Insert method is used to insert a new item at index 0 in the appraisalBases list. This item represents the option to query all records. The properties Id, BaseType, AppraisalBase, and IsDel are set accordingly.

3. cbxBase.DataSource is set to appraisalBases list, which will populate the ComboBox with the items from the list.

4. cbxBase.DisplayMember is set to "BaseType" so that the ComboBox will display the BaseType property of each item.

5. cbxBase.ValueMember is set to "BaseType" so that when an item is selected, the BaseType property of the selected item can be retrieved.

Note: Please make sure that the data type of the properties (Id, BaseType, AppraisalBase, IsDel) in the AppraisalBases class matches the data type expected