【场景】操作上有操作前确认提示，但是存在部分操作不生效，如下推；
【案例】通过表单插件，下推前进行提示
```python
import clr
clr.AddReference('Kingdee.BOS.Core')
from System import *
from Kingdee.BOS.Core.DynamicForm import *
def BeforeDoOperation(e):
opShowMsg = False;
keyConst = "Custom_Push_ShowMsg";
if(this.View.Session.ContainsKey(keyConst)):
opShowMsg = this.View.Session[keyConst];
if not e.Operation.FormOperation.Operation.Equals("Push",StringComparison.OrdinalIgnoreCase):
return;
if (opShowMsg):
this.View.Session[keyConst] = False;
return;
e.Cancel = True;
this.View.ShowMessage('下推前显示一个提示', MessageBoxOptions.OKCancel, lambda x: ReDoPush(x));
def ReDoPush(e):
keyConst = "Custom_Push_ShowMsg";
if e == MessageBoxResult.OK:
this.View.Session[keyConst] = True;
this.View.InvokeFormOperation("Push");
```
【效果】下推时进行交互确认提示
