问题
I have created datatable with checkbox. When user select checkbox, snackBar must be load (currently working good) with length of selected checkbox. But snakcbar loading everytime when user select more than one checkbox. How to load snackbar and just show length of selected ids.(without load snackbar everytime). Snackbar just need to show increment of selected ids. I push selected ids in public endorsementIds: string[] = [];. If endorsementIds length is 0, snackbar must hide. Here is my code in stackblitz. Thank you in advance :)
来源：https://stackoverflow.com/questions/55292538/angular-7-how-to-load-material-snackbar-when-checkbox-checked-in-datatable