如何在包中存儲sparsearray

Question

我有一個SparseArray<myObject>，並希望在我的活動中將其存儲在onSaveInstanceState方法中，並在oncreate中將其恢復。我在包中發現putSparseParcelableArray方法把SparseArray和onSaveInstanceState方法做：

bundle.putSparseParcelableArray("mySparseArray", mySparseArray); 

但是文摘顯示了這個錯誤：

The method putSparseParcelableArray(String, SparseArray<? extends Parcelable>) in the type Bundle is not applicable for the arguments (String, SparseArray<myObject>) 

而且速戰速決撒開參數mySparsArray到SparseArray<? extends Parcelable>，但如果我這樣做，並且把它在onCreate方法：

mySparseArray = (SparseArray<myObject>) savedInstanceState.getSparseParcelableArray("mySparseArray"); 

它得到這個錯誤：

Cannot cast from SparseArray<Parcelable> to SparseArray<myObject> 

如果這種方式是錯誤的，將mySparseArray放入捆綁包的解決方案是什麼？ 任何幫助將不勝感激。

Answer 1

您的班級應執行Parcelable，並且應該有一個名爲CREATOR的靜態最終成員變量Parcelable.Creator<myObject>。

Answer 2

可以擴展到SparsArray一個imlement作爲序列化使用它：

import java.io.IOException; 
import java.io.ObjectInputStream; 
import java.io.ObjectOutputStream; 
import java.io.Serializable; 
import android.util.SparseArray; 



/** 
* @author Asaf Pinhassi www.mobiledev.co.il 
* @param <E> 
* 
*/ 
public class SerializableSparseArray<E> extends SparseArray<E> implements Serializable{ 

    private static final long serialVersionUID = 824056059663678000L; 

    public SerializableSparseArray(int capacity){ 
     super(capacity); 
    } 

    public SerializableSparseArray(){ 
     super(); 
    } 

    /** 
    * This method is private but it is called using reflection by java 
    * serialization mechanism. It overwrites the default object serialization. 
    * 
    * <br/><br/><b>IMPORTANT</b> 
    * The access modifier for this method MUST be set to <b>private</b> otherwise {@link java.io.StreamCorruptedException} 
    * will be thrown. 
    * 
    * @param oos 
    *   the stream the data is stored into 
    * @throws IOException 
    *    an exception that might occur during data storing 
    */ 
    private void writeObject(ObjectOutputStream oos) throws IOException { 
     Object[] data = new Object[size()]; 

     for (int i=data.length-1;i>=0;i--){ 
      Object[] pair = {keyAt(i),valueAt(i)}; 
      data[i] = pair; 
     } 
     oos.writeObject(data); 
    } 

    /** 
    * This method is private but it is called using reflection by java 
    * serialization mechanism. It overwrites the default object serialization. 
    * 
    * <br/><br/><b>IMPORTANT</b> 
    * The access modifier for this method MUST be set to <b>private</b> otherwise {@link java.io.StreamCorruptedException} 
    * will be thrown. 
    * 
    * @param oos 
    *   the stream the data is read from 
    * @throws IOException 
    *    an exception that might occur during data reading 
    * @throws ClassNotFoundException 
    *    this exception will be raised when a class is read that is 
    *    not known to the current ClassLoader 
    */ 
    private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException { 
     Object[] data = (Object[]) ois.readObject(); 
     for (int i=data.length-1;i>=0;i--){ 
      Object[] pair = (Object[]) data[i]; 
      this.append((Integer)pair[0],(E)pair[1]); 
     } 
     return; 
    } 


}