Question

我想通过intentExtra传递Collection []数组，但它不会工作。

                Intent intent = new Intent(SzabadEuMusorokLeirasActivity.this, SzabadEuMusorokViewActivity.class);
            JSONdata jsonData = new JSONdata("http://1956.osaarchivum.org/api/items?collection=13");
            intent.putExtra("ARRAY_EXTRA", jsonData.getCollections());
            startActivity(intent);

在另一项活动中：

Intent intent = getIntent();
    Parcelable[] parcelables = intent.getParcelableArrayExtra("ASD");
    mCollections = Arrays.copyOf(parcelables, parcelables.length, Collection[].class);

如果它到达mCollections = Arrays.copyOf（...）行，它会得到一个NullPointerException，因为parcelables.length为null ...

这是Collection类：

public class Collection implements Parcelable{

private String mTitile;
private String mSubject;
private String mMediaURL;

public Collection() {}

protected Collection(Parcel in){
    mTitile = in.readString();
    mSubject = in.readString();
    mMediaURL = in.readString();
}

public static final Creator<Collection> CREATOR = new Creator<Collection>() {
    @Override
    public Collection createFromParcel(Parcel in) {
        return new Collection(in);
    }

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

public String getTitile() {
    return mTitile;
}

public void setTitile(String titile) {
    mTitile = titile;
}

public String getSubject() {
    return mSubject;
}

public void setSubject(String subject) {
    mSubject = subject;
}

public String getMediaURL() {
    return mMediaURL;
}

public void setMediaURL(String mediaURL) {
    mMediaURL = mediaURL;
}

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

@Override
public void writeToParcel(Parcel dest, int flags) {
    dest.writeString(mTitile);
    dest.writeString(mSubject);
    dest.writeString(mMediaURL);
}

}

Answer 1

好吧，你使用密钥＆＃34; ARRAY_EXTRA＆＃34;添加额外的内容，让你尝试使用密钥＆＃34; ASD＆＃34;在另一个Activity中提取它。那不会起作用。

    intent.putExtra("ARRAY_EXTRA", jsonData.getCollections());
    startActivity(intent);

在另一项活动中：

    Intent intent = getIntent();
    Parcelable[] parcelables = intent.getParcelableArrayExtra("ASD");

Answer 2

您应该在Intent类上使用putParcelableArrayListExtra()方法。因为您在接收器活动中使用getParcelableArrayListExtra()方法

为什么我不能通过意图传递对象数组？

2 个答案: