Question

我目前正在教自己关于课程，但遇到一个奇怪的错误，我必须做一些基本错误的事情，它一直说性别不在论证中，即使它是在男性之下。我的代码如下：

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.avantika.queueadmin.fragments.AddUserFragment">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:isScrollContainer="true"
        android:orientation="vertical">

        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="8dp"
            android:layout_marginTop="8dp">

            <EditText
                android:id="@+id/editTextAddUserFullName"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="Full Name"
                android:inputType="text" />
        </android.support.design.widget.TextInputLayout>

        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="8dp"
            android:layout_marginTop="8dp">

            <EditText
                android:id="@+id/editTextAddUserDisplayName"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="Display Name"
                android:inputType="text" />
        </android.support.design.widget.TextInputLayout>

        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="8dp"
            android:layout_marginTop="8dp">

            <EditText
                android:id="@+id/editTextAddUserMobile"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="Mobile No"
                android:inputType="number|phone" />
        </android.support.design.widget.TextInputLayout>

        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="8dp"
            android:layout_marginTop="8dp">

            <EditText
                android:id="@+id/editTextAddUserEmail"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="Email"
                android:inputType="text|textEmailAddress" />
        </android.support.design.widget.TextInputLayout>

        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="8dp"
            android:layout_marginTop="8dp">

            <EditText
                android:id="@+id/editTextAddUserAddress"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="Address"
                android:inputType="text|textMultiLine" />
        </android.support.design.widget.TextInputLayout>

        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="8dp"
            android:layout_marginTop="8dp">

            <EditText
                android:id="@+id/editTextAddUserUserName"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="User Name"
                android:inputType="text" />
        </android.support.design.widget.TextInputLayout>

        <TextView
            android:id="@+id/textView2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="TextView" />

        <Spinner
            android:id="@+id/spinnerAddUserGender"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

        <Button
            android:id="@+id/btnAddUserSave"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:text="Add Employee" />
    </LinearLayout>
</ScrollView>

Answer 1

您编写的classification函数是实例方法，这意味着它应该在类的实例上调用。您可以分两步完成：

bob = HumanClassification()        # create the instance
bob.classification(32, 6, 'male')  # call the method on it

但是将参数直接传递给__init__可能更有意义，而不是使用单独的方法。如果希望可以在不预先指定所有值的情况下创建实例，则可以提供默认参数。

class HumanClassification:
    def __init__(self, age=0, height=0, gender=''):
        self.age = age
        self.height = height
        self.gender = gender

使用列表作为默认参数is usually a bad idea，因此我使用空字符串作为gender的默认值。

另一种方法是将classification更改为classmethod，而不是常规方法。正如您目前所做的那样，classmethod通常直接在课堂上调用。一些类设计有使用classmethod实现的替代构造函数。这可能是这样的：

class HumanClassification:
    def __init__(self):
        self.age = 0
        self.height = 0
        self.gender = []

    @classmethod                # use the classmethod decorator
    def classification(cls, age, height, gender): # first arg is the class, not an instance
        self = cls()            # create a new instance by calling the class
        self.age = age
        self.height = height
        self.gender = gender
        return self             # return the instance

bob = HumanClassification.classification(32, 6, 'male')    # this works now
print (bob.age)

TypeError：classification（）缺少1个必要的位置参数：＆＃39;性别＆＃39;

1 个答案: