从 Parcelable 类读取和写入 java.util.Date

Reading and writing java.util.Date from Parcelable class

提问by Mesut

I'm working with Parcelable class. How can I read and write java.util.Dateobject to and from this class?

我正在使用 Parcelable 类。我如何java.util.Date从这个类读取和写入对象？

采纳答案by Pankaj Kumar

Use writeSerializablewhere Date is Serializable. (But not a good idea. See below for another better way)

使用writeSerializable其中 Date 是可序列化的。（但不是一个好主意。另一种更好的方法见下文）

@Override
public void writeToParcel(Parcel out, int flags) {
   // Write object
   out.writeSerializable(date_object);

}

private void readFromParcel(Parcel in) {
   // Read object
    date_object = (java.util.Date) in.readSerializable();

}

---

---

But Serializing operations consume much performance. How can overcome this?

但是序列化操作会消耗很多性能。怎样才能克服这个？

So better use is to convert date into Long while writing, and read Long and pass to Date constructor to get Date. See below code

所以更好的用法是在写入时将日期转换为Long，然后读取Long并传递给Date构造函数以获取Date。看下面的代码

   @Override
    public void writeToParcel(Parcel out, int flags) {
       // Write long value of Date
       out.writeLong(date_object.getTime());

    }

    private void readFromParcel(Parcel in) {
       // Read Long value and convert to date
        date_object = new Date(in.readLong());

    }

回答by Gopal Gopi

Dateclass implements Serializable...

Date类实现Serializable...

so you can write

所以你可以写

parcel.writeSerializable(java.util.Date)

and you can read like

你可以这样读

java.util.Date date = (java.util.Date)parcel.readSerializable();

回答by Satyaki Mukherjee

Try this in this way::

以这种方式试试这个::

for write::

用于写::

yourParse.writeSerializable(YourGivenDate)

for read::

供阅读::

Date myDate = yourParse.readSerializable();

回答by App-SoftwareFactory

Use date.getTime()for get Long format:

使用date.getTime()获取长格式：

public class MiClass implements Parcelable {
    Date date;

    public MiClass(Date date) {
        this.date = date;
    }

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

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeLong(date != null ? date.getTime() : -1);
    }

    protected MiClass(Parcel in) {
        long tmpDate = in.readLong();
        this.date = tmpDate == -1 ? null : new Date(tmpDate);
    }

    public static final Parcelable.Creator<MiClass> CREATOR = new Parcelable.Creator<MiClass>() {
        public MiClass createFromParcel(Parcel source) {
            return new MiClass(source);
        }

        public MiClass[] newArray(int size) {
            return new MiClass[size];
        }
    };
}

回答by Pavel Shorokhov

In Kotlinwe may create extension for Parcel - the simplest solution.

在Kotlin 中，我们可以为 Parcel 创建扩展——最简单的解决方案。

fun Parcel.writeDate(date: Date?) {
    writeLong(date?.time ?: -1)
}

fun Parcel.readDate(): Date? {
    val long = readLong()
    return if (long != -1L) Date(long) else null
}

And use it

并使用它

parcel.writeDate(date)
parcel.readDate()

回答by Shyam Kumar

Try this (Kotlin):

试试这个（科特林）：

data class DateParcel(val date: Date?):Parcelable {
constructor(parcel: Parcel) : this(parcel.readValue(Date::class.java.classLoader) as? Date
)

override fun writeToParcel(parcel: Parcel, flags: Int) {
    parcel.writeValue(date)
}

override fun describeContents(): Int {
    return 0
}

companion object CREATOR : Parcelable.Creator<DateParcel> {
    override fun createFromParcel(parcel: Parcel): DateParcel {
        return DateParcel(parcel)
    }

    override fun newArray(size: Int): Array<DateParcel?> {
        return arrayOfNulls(size)
    }
}}