即使调用了委托方法，collectionview单元也不可见

Question

我的#if `1` is integer mask = (df['IS_MAIN'] == 1) & (df['TYPE'] == 'PPRTYPE') #if 1 is string #mask = (df['IS_MAIN'] == '1') & (df['TYPE'] == 'PPRTYPE') if (df.loc[mask, 'NAME'].iloc[0] == 'SIGHT'): df.loc[mask , 'NAME'] = 'NOT APPLICABLE' print (df) TYPE NAME IS_MAIN 0 PPRTYPE TIME 0 1 PPRTYPE SIGHT 0 2 PPRTYPE NOT APPLICABLE 1 3 PNRDTL NOT FOUND 1 4 PPRTYPE SIGHT 0 5 PPRTYPE NOT APPLICABLE 1 的身高为40。UICollectionview为（25,25）。单元格未显示。每个委托方法调用都工作正常。

UICollectionviewcell

Answer 1

class yourviewcontroller:UICollectionViewDelegate ,UICollectionViewDataSource ,UICollectionViewDelegateFlowLayout{

}

UICollectionViewDelegateFlowLayout 添加此