Android Studio : Simple High Score Screen
上一篇 [程式] Android Studio : Simple Quiz Game 有說到，要增加一個排行榜(leaderboard)的功能，剛好也有範例，就直接來實作吧!
範例網址：
https://www.youtube.com/watch?v=_cV7cgQFDo0相關資訊圖片：
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| Simple High Screen Screen View1 (activity_main.xml)畫面 |
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| Simple High Screen Screen View2 (activity_best.xml)畫面 |
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| 初始畫面 |
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| High Score Screen畫面 |
Source Code：
activity_main.xml<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="20dp"
tools:context="tw.idv.wenyen.simplehighscorescreen.MainActivity">
<Button
android:id="@+id/b_add"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:text="1" />
<Button
android:id="@+id/b_end"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentEnd="true"
android:layout_alignParentRight="true"
android:text="END" />
<TextView
android:id="@+id/tv_score"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:textSize="24dp"
android:text="SCORE: 0" />
</RelativeLayout>
activity_best.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" android:padding="20dp"> <TextView android:id="@+id/tv_score" android:layout_width="match_parent" android:layout_height="wrap_content" android:gravity="center" android:text="" /> </LinearLayout>
MainActivity.java
package tw.idv.wenyen.simplehighscorescreen;
import android.content.Intent;
import android.content.SharedPreferences;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
TextView tv_score;
Button b_add, b_end;
int score = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv_score = findViewById(R.id.tv_score);
b_add = findViewById(R.id.b_add);
b_end = findViewById(R.id.b_end);
tv_score.setText("SCORE: " + score);
b_add.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
score++;
tv_score.setText("SCORE: " + score);
}
});
b_end.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
//save score in SharedPreferences
SharedPreferences preferences = getSharedPreferences("PREFS", 0);
SharedPreferences.Editor editor = preferences.edit();
editor.putInt("lastScore", score);
editor.apply();
//go to BestActivity
Intent intent = new Intent(getApplicationContext(), BestActivity.class);
startActivity(intent);
finish();
}
});
}
}
BestActivity.java
package tw.idv.wenyen.simplehighscorescreen;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;
/**
* Created by kingbow on 2018/3/22.
*/
public class BestActivity extends AppCompatActivity {
TextView tv_score;
int lastScore;
int best1, best2, best3;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_best);
tv_score = findViewById(R.id.tv_score);
// load old score
SharedPreferences preferences = getSharedPreferences("PREFS", 0);
lastScore = preferences.getInt("lastScore", 0);
best1 = preferences.getInt("best1", 0);
best2 = preferences.getInt("best2", 0);
best3 = preferences.getInt("best3", 0);
// replace if there is a high score
// ex : init status
// best1(5), best2(3), best3(1), lastScore(6)
if (lastScore > best3) {
best3 = lastScore;
SharedPreferences.Editor editor = preferences.edit();
editor.putInt("best3", best3);
editor.apply();
}
// best1(5), best2(3), best3(6), lastScore(6)
if (lastScore > best2) {
int temp = best2;
best2 = lastScore;
best3 = temp;
SharedPreferences.Editor editor = preferences.edit();
editor.putInt("best3", best3);
editor.putInt("best2", best2);
editor.apply();
}
// best1(5), best2(6), best3(3), lastScore(6)
if (lastScore > best1) {
int temp = best1;
best1 = lastScore;
best2 = temp;
SharedPreferences.Editor editor = preferences.edit();
editor.putInt("best2", best2);
editor.putInt("best1", best1);
editor.apply();
}
// final status
// best1(6), best2(5), best3(3), lastScore(6)
// display score
tv_score.setText("LAST SCORE: " + lastScore + "\n" +
"BEST1: " + best1 + "\n" +
"BEST2: " + best2 + "\n" +
"BEST3: " + best3);
}
@Override
public void onBackPressed() {
// go to MainActivity
Intent intent = new Intent(getApplicationContext(), MainActivity.class);
startActivity(intent);
finish();
}
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="tw.idv.wenyen.simplehighscorescreen">
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<!--新增activity-->
<activity android:name=".BestActivity" />
</application>
</manifest>
實作心得：
這個範例用到 Intent 與 SharedPreferences ，Intent 用於Activity的交換，除非是前面幾個簡單的範例遊戲，否則幾乎都會用到，所以要花些時間學習，另外 SharedPreferences 用於儲存、新增、刪除等資料處理，因此製作排行榜非常好用。雖然使用到LinearLayout，不過只用的其中的一個欄位，將分數與前三名塞入，真的有點太簡單了，下次將資料塞入ListView，做個比較完整的排行榜吧!
在第一次安裝APP時，出現 INSTALL_FAILED_INSUFFICIENT_STORAGE 的錯誤訊息，上網查詢的答案是空間已滿，可是查詢手機內部空間，卻還有足夠的空間，原本以為是手機的問題，要改用另外一台筆記型電腦的AVD，結果發現是BestActivity.java的其中一行lastScore打錯成PREFS，改正後就可以成功安裝，所以說一種錯誤訊息所顯示的可能不只是一種錯誤，
lastScore = preferences.getInt("PREFS", 0);成功安裝後，再改回 PREFS ，APP卻能夠成功安裝，這個錯誤真有趣，有機會再找時間研究。
參考資料：
補充說明：
2018/03/23 忘記Activity的交換，要在AndroidManifest.xml新增權限的部分寫上來，還好有想到。
0 意見:
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