serializers.SerializerMethodField和钩子方法结合，可以实现对ModelSerializer类的一些字段进行二次加工，返回，如下：1、对以ModelSerializer的类为外键数据进行处理
model如下：
A、Project
class Project(models.Model): """ 项目表 """ id = models.AutoField(primary_key=True) name = models.CharField(max_length=50, verbose_name='项目名称') version = models.CharField(max_length=50, verbose_name='版本') description = models.CharField(max_length=1024, blank=True, null=True, verbose_name='描述') status = models.BooleanField(default=True, verbose_name='状态') LastUpdateTime = models.DateTimeField(auto_now=True, verbose_name='最近修改时间') createTime = models.DateTimeField(auto_now_add=True, verbose_name='创建时间') user = models.ForeignKey(User, on_delete=models.SET_NULL, null=True, max_length=1024, verbose_name='创建人') def __unicode__(self): return self.name def __str__(self): return self.name class Meta: verbose_name = '项目' verbose_name_plural = '项目'
B、ApiInfo （以project为外键）
class ApiInfo(models.Model): """ 接口信息 """ id = models.AutoField(primary_key=True) project = models.ForeignKey(Project, related_name='api_project', on_delete=models.CASCADE, verbose_name='所属项目') def __unicode__(self): return self.name def __str__(self): return self.name class Meta: verbose_name = '接口' verbose_name_plural = '接口管理'
2、project的ModelSerializer如下：
class ProjectSerializer(serializers.ModelSerializer): """ 项目信息序列化 """ apiCount = serializers.SerializerMethodField() LastUpdateTime = serializers.DateTimeField(format="%Y-%m-%d %H:%M:%S", required=False, read_only=True) createTime = serializers.DateTimeField(format="%Y-%m-%d %H:%M:%S", required=False, read_only=True) user = serializers.CharField(source='user.first_name') class Meta: model = Project fields = ('id', 'name', 'version', 'type', 'status', 'LastUpdateTime', 'createTime', 'apiCount', 'dynamicCount', 'memberCount', 'description', 'user') def get_apiCount(self, obj): return obj.api_project.all().count() 通过 obj.以它为外键的类字段的related_name 取出以它为外键的对象，该对象可以进行进行一般的model类操作（如obj.api_project.all().count()、obj.api_project.get（XXX查询条件）.XXX属性），从而处理以它为外键的数据
