如何将Enum对象添加到Android Bundle中?


最好从myEnumValue.name()中将其作为字符串传递,并从yourenum . valueof (s)中恢复,否则必须保留枚举的顺序!

更详细的解释:从枚举序数转换为枚举类型


枚举是可序列化的,所以没有问题。

给定以下enum:

enum YourEnum {
  TYPE1,
  TYPE2
}

包:

// put
bundle.putSerializable("key", YourEnum.TYPE1);

// get 
YourEnum yourenum = (YourEnum) bundle.get("key");

目的:

// put
intent.putExtra("key", yourEnum);

// get
yourEnum = (YourEnum) intent.getSerializableExtra("key");

我知道这是一个老问题,但我也遇到了同样的问题,我想分享一下我是如何解决它的。关键是Miguel所说的:枚举是可序列化的。

给定以下enum:

enum YourEnumType {
    ENUM_KEY_1, 
    ENUM_KEY_2
}

Put:

Bundle args = new Bundle();
args.putSerializable("arg", YourEnumType.ENUM_KEY_1);

为了完整起见,这是一个完整的示例,说明如何从bundle中放入和返回enum。

给定以下enum:

enum EnumType{
    ENUM_VALUE_1,
    ENUM_VALUE_2
}

你可以把枚举放到一个bundle中:

bundle.putSerializable("enum_key", EnumType.ENUM_VALUE_1);

并返回enum:

EnumType enumType = (EnumType)bundle.getSerializable("enum_key");

另一个选择:

public enum DataType implements Parcleable {
    SIMPLE, COMPLEX;

    public static final Parcelable.Creator<DataType> CREATOR = new Creator<DataType>() {

        @Override
        public DataType[] newArray(int size) {
            return new DataType[size];
        }

        @Override
        public DataType createFromParcel(Parcel source) {
            return DataType.values()[source.readInt()];
        }
    };

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeInt(this.ordinal());
    }
}

使用包。putSerializable(String key, Serializable s)和bundle。getSerializable (String键):

enum Mode = {
  BASIC, ADVANCED
}

Mode m = Mode.BASIC;

bundle.putSerializable("mode", m);

...

Mode m;
m = bundle.getSerializable("mode");

文档:http://developer.android.com/reference/android/os/Bundle.html


一种简单的方法,将整数值赋给enum

示例如下:

public enum MyEnum {

    TYPE_ONE(1), TYPE_TWO(2), TYPE_THREE(3);

    private int value;

    MyEnum(int value) {
        this.value = value;
    }

    public int getValue() {
        return value;
    }

}

发件人页面:

Intent nextIntent = new Intent(CurrentActivity.this, NextActivity.class);
nextIntent.putExtra("key_type", MyEnum.TYPE_ONE.getValue());
startActivity(nextIntent);

接收端:

Bundle mExtras = getIntent().getExtras();
int mType = 0;
if (mExtras != null) {
    mType = mExtras.getInt("key_type", 0);
}

/* OR
    Intent mIntent = getIntent();
    int mType = mIntent.getIntExtra("key_type", 0);
*/

if(mType == MyEnum.TYPE_ONE.getValue())
    Toast.makeText(NextActivity.this, "TypeOne", Toast.LENGTH_SHORT).show();
else if(mType == MyEnum.TYPE_TWO.getValue())
    Toast.makeText(NextActivity.this, "TypeTwo", Toast.LENGTH_SHORT).show();
else if(mType == MyEnum.TYPE_THREE.getValue())
    Toast.makeText(NextActivity.this, "TypeThree", Toast.LENGTH_SHORT).show();
else
    Toast.makeText(NextActivity.this, "Wrong Key", Toast.LENGTH_SHORT).show();

我认为将enum转换为int(对于普通enum),然后设置在bundle上是最简单的方法。就像下面的代码:

myIntent.PutExtra("Side", (int)PageType.Fornt);

然后检查状态:

int type = Intent.GetIntExtra("Side",-1);
if(type == (int)PageType.Fornt)
{
    //To Do
}

但并不适用于所有枚举类型!


我用高棉。

companion object {

        enum class Mode {
            MODE_REFERENCE,
            MODE_DOWNLOAD
        }
}

然后放入Intent:

intent.putExtra(KEY_MODE, Mode.MODE_DOWNLOAD.name)

当你上网获得价值时:

mode = Mode.valueOf(intent.getStringExtra(KEY_MODE))

有一点需要注意,如果你使用bundle。将一个Bundle添加到通知中,你可能会遇到以下问题:

*** Uncaught remote exception!  (Exceptions are not yet supported across processes.)
    java.lang.RuntimeException: Parcelable encountered ClassNotFoundException reading a Serializable object.

...

要解决这个问题,你可以做以下事情:

public enum MyEnum {
    TYPE_0(0),
    TYPE_1(1),
    TYPE_2(2);

    private final int code;

    private MyEnum(int code) {
        this.code = navigationOptionLabelResId;
    }

    public int getCode() {
        return code;
    }

    public static MyEnum fromCode(int code) {
        switch(code) {
            case 0:
                return TYPE_0;
            case 1:
                return TYPE_1;
            case 2:
                return TYPE_2;
            default:
                throw new RuntimeException(
                    "Illegal TYPE_0: " + code);
        }
    }
}

然后可以这样使用:

// Put
Bundle bundle = new Bundle();
bundle.putInt("key", MyEnum.TYPE_0.getCode());

// Get 
MyEnum myEnum = MyEnum.fromCode(bundle.getInt("key"));

对于Intent,你可以这样使用:

意图:kotlin

FirstActivity:

val intent = Intent(context, SecondActivity::class.java)
intent.putExtra("type", typeEnum.A)
startActivity(intent)

SecondActivity:

override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState) 
     //...
     val type = (intent.extras?.get("type") as? typeEnum.Type?)
}

我创建了一个Koltin扩展:

fun Bundle.putEnum(key: String, enum: Enum<*>) {
    this.putString( key , enum.name )
}

inline fun <reified T: Enum<T>> Intent.getEnumExtra(key:String) : T {
    return enumValueOf( getStringExtra(key) )
}

创建一个bundle并添加:

Bundle().also {
   it.putEnum( "KEY" , ENUM_CLAS.ITEM )
}

并获得:

intent?.getEnumExtra< ENUM_CLAS >( "KEY" )?.let{}


在芬兰湾的科特林:

enum class MyEnum {
  NAME, SURNAME, GENDER
}

把这个枚举放在一个Bundle中:

Bundle().apply {
  putInt(MY_ENUM_KEY, MyEnum.ordinal)
}

从Bundle中获取enum:

val ordinal = getInt(MY_ENUM_KEY, 0)
MyEnum.values()[ordinal]

完整的例子:

class MyFragment : Fragment() {

    enum class MyEnum {
        NAME, SURNAME, GENDER
    }

    companion object {
        private const val MY_ENUM_KEY = "my_enum_key"

        fun newInstance(myEnum: MyEnum) = MyFragment().apply {
            arguments = Bundle().apply {
                putInt(MY_ENUM_KEY, myEnum.ordinal)
            }
        }
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        with(requireArguments()) {
            val ordinal = getInt(MY_ENUM_KEY, 0)
            val myEnum = MyEnum.values()[ordinal]
        }
    }
}

在Java中:

public final class MyFragment extends Fragment {
    private static final String MY_ENUM_KEY = "my_enum";

    public enum MyEnum {
        NAME,
        SURNAME,
        GENDER
    }

    public final MyFragment newInstance(MyEnum myEnum) {
        Bundle bundle = new Bundle();
        bundle.putInt(MY_ENUM_KEY, myEnum.ordinal());
        MyFragment fragment = new MyFragment();
        fragment.setArguments(bundle);
        return fragment;
    }

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Bundle arguments = this.requireArguments();
        int ordinal = arguments.getInt(MY_ENUM_KEY, 0);
        MyEnum myEnum = MyEnum.values()[ordinal];
    }
}

这对我来说很容易:

enum class MyEnum {
    FOO,
    BAR
}


val bundle = Bundle()
bundle.putAll(bundleOf("myKey", MyEnum.FOO))

// to read
val myEnum = bundle.get("myKey") as MyEnumClass

注意,如果你从onCreate得到这个,你会想使用as?防止任何空异常。


enum YourEnum { 类型1, 类型2 }

传递bundle as bundleOf("TYPE" to youenum . type1)

收到, 参数?。let {it.getSerializable(B"TYPE") as YourEnum}