【发布时间】：2020-07-15 11:42:11
【问题描述】：
我是新来的，也是编程新手。我目前正在做一个项目，现在我已经被困了一周。我唯一想做的就是保存两个变量，以便在应用程序关闭并重新打开后仍然可以看到它。同样由于某种原因，当我打开设置活动时，我的变量值被设置回零。
我知道其他人已经发布了类似的问题，但我无法将其应用于我的工作。我不明白我读到的很多东西，比如 SharedPreferences、onPause() 和 GAME_STATE_KEY。任何人都可以在不链接 Android 文档文章的情况下解释如何做这样的事情吗？我什至不明白文档说什么，复制/粘贴代码似乎不起作用。
这是我的 MainActivity
package com.example.courtcounter;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import java.text.SimpleDateFormat;
import java.util.Date;
public class MainActivity<format> extends AppCompatActivity {
TextView textView;
int scoreTeamA = 0;
int scoreTeamB = 0;
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("dd/MM/yyyy\n hh:mm aa");
String format = simpleDateFormat.format(new Date());
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView = (TextView) findViewById(R.id.team_a_score);
FloatingActionButton fab = findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
String shareMessage = createMessage(format, scoreTeamA, scoreTeamB);
Intent intent = new Intent(Intent.ACTION_SEND);
intent.putExtra(Intent.EXTRA_SUBJECT, "Match Score");
intent.setType("text/*");
intent.putExtra(Intent.EXTRA_TEXT, shareMessage);
if (intent.resolveActivity(getPackageManager()) != null) {
startActivity(intent);
}
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings){
Intent intent = new Intent(this, SettingsActivity.class);
startActivity(intent);
return true;
}
return super.onOptionsItemSelected(item);
}
private String createMessage(String date, int TeamA, int TeamB){
EditText editTeamA = findViewById(R.id.team_a_name);
String teamAName =editTeamA.getText().toString();
EditText editTeamB = findViewById(R.id.team_b_name);
String teamBName = editTeamB.getText().toString();
String shareMessage =format +"\n"+ teamAName+ " : "+ TeamA + "\n" + teamBName + " : "+ TeamB;
return shareMessage;
}
/** Resets score of boths teams to 0
*/
public void resetScore(View v){
scoreTeamA = 0;
scoreTeamB = 0;
displayForTeamA(scoreTeamA);
displayForTeamB(scoreTeamB);
}
/**
* Displays the given score for Team A.
*/
public void displayForTeamA(int scoreTeamA){
TextView scoreViewA = (TextView)findViewById(R.id.team_a_score);
String teamA = scoreViewA.getText().toString();
scoreViewA.setText(String.valueOf(scoreTeamA));
}
/**
* Displays the given score for Team B.
*/
public void displayForTeamB(int score) {
TextView scoreViewB = (TextView) findViewById(R.id.team_b_score);
String teamB = scoreViewB.getText().toString();
scoreViewB.setText(String.valueOf(score));
}
/**
* This method is called when the +3 points button is clicked.
*/
public void ThreeA(View view){
scoreTeamA = scoreTeamA +3;
displayForTeamA(scoreTeamA);
}
/**
* This method is called when the +2 points button is clicked.
*/
public void TwoA(View view){
scoreTeamA = scoreTeamA +2;
displayForTeamA(scoreTeamA);
}
/**
* This method is called when the FREE THROW button is clicked.
*/
public void OneA(View view){
scoreTeamA = scoreTeamA + 1;
displayForTeamA(scoreTeamA);
}
/**
* This method is called when the +3 points button is clicked.
*/
public void ThreeB(View view){
scoreTeamB = scoreTeamB +3;
displayForTeamB(scoreTeamB);
}
/**
* This method is called when the +2 points button is clicked.
*/
public void TwoB(View view){
scoreTeamB = scoreTeamB +2;
displayForTeamB(scoreTeamB);
}
/**
* This method is called when the FREE THROW button is clicked.
*/
public void OneB(View view){
scoreTeamB = scoreTeamB + 1;
displayForTeamB(scoreTeamB);
}
}
我是否必须更改我的 SettingActivity 和 SettingsFragment 来帮助解决这个问题，还是不需要？
谢谢。
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