我目前正在为一个记分小助手应用程序开发个人项目。该应用的目的是使用它来跟踪每个玩家的得分,并具有高分和其他花哨的功能。
现在,我有一个使用ViewPager2的选项卡活动。对于那些熟悉它的人来说,你会知道比我多得多,但我注意到的是,在活动中从未实例化我的Fragment类,只在FragmentStateAdapter中实例化。在我的活动中,我仅使用两个选项卡,一个用于游戏方面,另一个用于显示得分。考虑到这一点,我的活动类如下所示:
EightHoleActivity.java
如您所见,我有一个
我想做什么:
我想将从
我尝试使用
以下是我使用的其他类。请注意,
现在,我有一个使用ViewPager2的选项卡活动。对于那些熟悉它的人来说,你会知道比我多得多,但我注意到的是,在活动中从未实例化我的Fragment类,只在FragmentStateAdapter中实例化。在我的活动中,我仅使用两个选项卡,一个用于游戏方面,另一个用于显示得分。考虑到这一点,我的活动类如下所示:
EightHoleActivity.java
package com.example.game;
import android.content.Intent;
import android.os.Bundle;
import com.google.android.material.tabs.TabLayout;
import com.google.android.material.tabs.TabLayoutMediator;
import androidx.appcompat.app.AppCompatActivity;
import androidx.viewpager2.widget.ViewPager2;
public class EightHoleActivity extends AppCompatActivity {
private long gameID;
private RoomDB database;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_eight_hole);
Intent intent = getIntent();
gameID = intent.getLongExtra("GameID", 0);
database = RoomDB.getInstance(EightHoleActivity.this);
ViewPager2 viewPager2 = findViewById(R.id.eight_hole_view_pager);
viewPager2.setAdapter(new EightHolePagerAdapter(this));
TabLayout tabLayout = findViewById(R.id.eight_hole_tabs);
TabLayoutMediator tabLayoutMediator = new TabLayoutMediator(
tabLayout, viewPager2, (tab, position) -> {
switch (position){
case 0: {
tab.setText("Current game");
tab.setIcon(R.drawable.ic_twotone_games_24);
break;
}
default: {
tab.setText("Scores");
tab.setIcon(R.drawable.ic_baseline_list_24);
break;
}
}
}
);
tabLayoutMediator.attach();
}
}
如您所见,我有一个
RoomDatabase
,用于存储应用程序中的数据。当我通过意图启动此活动时,我传递正在进行的游戏的ID
。这就是我遇到问题的地方。我想做什么:
我想将从
intent.getLongExtra("GameID", 0)
获取的变量gameID
一直传递到EightHoleScoresFragment
类。我尝试使用
Bundle
和putParcelableArrayList()
,但没有成功。以下是我使用的其他类。请注意,
Participants.java
类是我想要提取的,其中包括gameID
变量。package com.example.game;
import android.os.Parcel;
import android.os.Parcelable;
import androidx.annotation.Nullable;
import androidx.room.ColumnInfo;
import androidx.room.Entity;
import androidx.room.ForeignKey;
import androidx.room.PrimaryKey;
import java.util.Objects;
@Entity(tableName = "participants", foreignKeys = {
@ForeignKey(entity = Player.class, parentColumns = "id", childColumns = "player_id", onDelete = ForeignKey.CASCADE),
@ForeignKey(entity = Game.class, parentColumns = "id", childColumns = "game_id", onDelete = ForeignKey.CASCADE)})
public class Participant implements Parcelable {
@PrimaryKey(autoGenerate = true)
private long id;
@ColumnInfo(name = "player_id", index = true)
private long playerID;
@ColumnInfo(name = "game_id", index = true)
private long gameID;
@ColumnInfo(name = "score")
private int score;
protected Participant(Parcel in) {
id = in.readLong();
playerID = in.readLong();
gameID = in.readLong();
score = in.readInt();
}
public static final Creator<Participant> CREATOR = new Creator<Participant>() {
@Override
public Participant createFromParcel(Parcel in) {
return new Participant(in);
}
@Override
public Participant[] newArray(int size) {
return new Participant[size];
}
};
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public long getPlayerID() {
return playerID;
}
public void setPlayerID(long playerID) {
this.playerID = playerID;
}
public long getGameID() {
return gameID;
}
public void setGameID(long gameID) {
this.gameID = gameID;
}
public int getScore() {
return score;
}
public void setScore(int score) {
this.score = score;
}
public Participant(long playerID, long gameID){
this.playerID = playerID;
this.gameID = gameID;
}
@Override
public boolean equals(@Nullable Object obj) {
if (this == obj) return true;
if (!(obj instanceof Participant)) return false;
Participant participant = (Participant) obj;
if (id != participant.id) return false;
return Objects.equals(score, participant.score) || Objects.equals(playerID, participant.playerID) || Objects.equals(gameID, participant.gameID);
}
@Override
public int hashCode() {
int result = (int) id;
result = (int) (31 * result + playerID + gameID + score);
return result;
}
@Override
public String toString() {
return "Participant{" +
"ID=" + id +
", PlayerID='" + playerID + '\'' +
", GameID='" + gameID + '\'' +
", Score='" + score + '\'' +
'}';
}
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeLong(id);
dest.writeLong(playerID);
dest.writeLong(gameID);
dest.writeInt(score);
}
}
EightHolePagerAdapter.java
package com.example.game;
import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentActivity;
import androidx.viewpager2.adapter.FragmentStateAdapter;
public class EightHolePagerAdapter extends FragmentStateAdapter {
public EightHolePagerAdapter(@NonNull FragmentActivity fragmentActivity) {
super(fragmentActivity);
}
@NonNull
@Override
public Fragment createFragment(int position) {
switch (position){
case 0:
return new EightHoleGameFragment();
default:
return new EightHoleScoresFragment();
}
}
@Override
public int getItemCount() {
return 2;
}
}
EightHoleScoresFragment.java
package com.example.game;
import android.os.Bundle;
import androidx.fragment.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListView;
import java.util.ArrayList;
public class EightHoleScoresFragment extends Fragment {
private ArrayList<Participant> participants = new ArrayList<Participant>();
public EightHoleScoresFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_eight_hole_scores, container, false);
ListView listView = (ListView) view.findViewById(R.id.eight_hole_current_scores_list);
ScoresAdapter adapter = new ScoresAdapter(getActivity(), R.layout.scores_adapter_layout, participants);
listView.setAdapter(adapter);
return view;
}
}
非常抱歉代码量如此之大,但我认为这些都是必要的,才能理解正在发生的事情。我已经尝试使用Bundle
,遵循网站上的各种答案,但都没有成功。我想知道是否有可能直接将意图的内容传递给链接回父级EightHoleActivity
的方法,并将其传递到EightHoleScoresFragment
中,但我不确定...
提前致谢!