Question

我的代码遇到问题，我会对一个概念的具体解释感兴趣。基本上，我了解SharedPreferences是如何工作的，我知道键值的概念，但是尽管我在官方文档和其他网站上进行了搜索，但是我无法弄清楚映射的工作方式。

我正在制作一个类似“ M.Mood”的应用。当用户向上或向下滚动时，心情和心情的颜色都在变化。单击历史记录时，新活动中将出现一个新屏幕，该屏幕显示最近7天的值。

这是我的问题：我从HistoryActivity.java中的MainActivity.java中检索了SharedPreferences，尝试对其进行映射，但是TextViews的颜色仍然保持红色。作为Java的初学者，我想就为什么它不显示我在colors.xml资源中注册的颜色发表您的看法。

这是我的MainActivity.java文件：

package com.lepanda.studioneopanda.moodtracker;

// all my imports

public class MainActivity extends AppCompatActivity implements 
SimpleGestureDetector.SimpleGestureListener {

ImageButton comment;
ImageButton history;
EditText input;
ImageView iv;
RelativeLayout container;
int tableMood[] = {R.drawable.smiley_sad, R.drawable.smiley_disappointed, R.drawable.smiley_normal, R.drawable.smiley_happy, R.drawable.smiley_super_happy};
int currentMood;
int tableColor[] = {R.color.faded_red, R.color.warm_grey, R.color.cornflower_blue_65, R.color.light_sage, R.color.banana_yellow};
int currentColor;
int currentComColor;
int currentHisColor;

private SimpleGestureDetector detector;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    iv = findViewById(R.id.iv);
    currentMood = 3;
    iv.setImageResource(tableMood[currentMood]);

    container = findViewById(R.id.container);
    currentColor = 3;
    container.setBackgroundResource(tableColor[currentColor]);

    comment = findViewById(R.id.comment);
    currentComColor = 3;
    comment.setBackgroundResource(tableColor[currentComColor]);

    history = findViewById(R.id.history);
    currentHisColor = 3;
    history.setBackgroundResource(tableColor[currentHisColor]);

    // Detect touched area
    detector = new SimpleGestureDetector(MainActivity.this, this);

    //history button click + sharedpref and manage calendar

//Creating the dialog box prompting user for a message
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle("Add comment");
    builder.setMessage("Comment vous sentez-vous ?");

    input = new EditText(this);
    builder.setView(input);

    //Create PositiveButton
    builder.setPositiveButton("Enregistrer", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            String txt = input.getText().toString();
            Toast.makeText(getApplicationContext(), txt, Toast.LENGTH_LONG).show();
        }
    });

    //Create NegativeButton
    builder.setNegativeButton("Annuler", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            dialog.dismiss();
        }
    });

    final AlertDialog ad = builder.create();
    //Button
    comment.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            ad.show();
        }
    });

    ImageButton history = findViewById(R.id.history);
    history.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            startHistory();
        }
    });

    if (getMood() != tableMood[currentMood]){
        iv.setImageResource(tableMood[getMood()]);
    }
}

private void startHistory() {
    startActivity(new Intent(MainActivity.this, HistoryActivity.class));
}

@Override
public boolean dispatchTouchEvent(MotionEvent me) {
    // Call onTouchEvent of SimpleGestureFilter class
    this.detector.onTouchEvent(me);
    return super.dispatchTouchEvent(me);
}

@Override
public void onSwipe(int direction) {

    //Detect the swipe gestures and display toast
    String showToastMessage = "";

    switch (direction) {

        case SimpleGestureDetector.SWIPE_UP:
            showToastMessage = "You have Swiped Up.";
            if (currentMood == 4) {
                showToastMessage = "Vous êtes vraiment si content ?";
            } else {
                currentMood++;
                iv.setImageResource(tableMood[currentMood]);
                currentColor++;
                container.setBackgroundResource(tableColor[currentColor]);
                currentComColor++;
                comment.setBackgroundResource(tableColor[currentComColor]);
                currentHisColor++;
                history.setBackgroundResource(tableColor[currentHisColor]);
                storeMood(currentMood);

            }
            break;

        case SimpleGestureDetector.SWIPE_DOWN:
            showToastMessage = "You have Swiped Down.";
            if (currentMood == 0) {
                showToastMessage = "Vous êtes vraiment si malheureux ?";
            } else {
                currentMood--;
                iv.setImageResource(tableMood[currentMood]);
                currentColor--;
                container.setBackgroundResource(tableColor[currentColor]);
                currentComColor--;
                comment.setBackgroundResource(tableColor[currentComColor]);
                currentHisColor--;
                history.setBackgroundResource(tableColor[currentHisColor]);
                storeMood(currentMood);
            }
            break;
    }
    Toast.makeText(this, showToastMessage, Toast.LENGTH_SHORT).show();
}


public void storeMood(int mood) {
    SharedPreferences msharedPreferences = getSharedPreferences("monP3", MODE_PRIVATE);
    SharedPreferences.Editor mEditor = msharedPreferences.edit();
    String dayNumberKey = android.text.format.DateFormat.format("yyyyMMddhms", new java.util.Date()).toString();
    mEditor.putInt(dayNumberKey, mood);
    mEditor.apply();
}
private int getMood(){
    SharedPreferences msharedPreferences = getSharedPreferences("monP3", MODE_PRIVATE);
    String dayNumberKey = android.text.format.DateFormat.format("yyyyMMddhms", new java.util.Date()).toString();
    int actualMood = msharedPreferences.getInt(dayNumberKey, currentMood);
    return actualMood;
}

}

这是我的HistoryActivity.java文件：

package com.lepanda.studioneopanda.moodtracker;

// imports

public class HistoryActivity extends AppCompatActivity {

int tableMood[] = {R.drawable.smiley_sad, R.drawable.smiley_disappointed, R.drawable.smiley_normal, R.drawable.smiley_happy, R.drawable.smiley_super_happy};
int tableColor[] = {R.color.faded_red, R.color.warm_grey, R.color.cornflower_blue_65, R.color.light_sage, R.color.banana_yellow};

int currentColor;
int currenMood;

TextView view1;
TextView view2;
TextView view3;
TextView view4;
TextView view5;
TextView view6;
TextView view7;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_history);

    SharedPreferences msharedPreferences = getSharedPreferences("monP3", MODE_PRIVATE);

    view1 = findViewById(R.id.textView1);
    view2 = findViewById(R.id.textView2);
    view3 = findViewById(R.id.textView3);
    view4 = findViewById(R.id.textView4);
    view5 = findViewById(R.id.textView5);
    view6 = findViewById(R.id.textView6);
    view7 = findViewById(R.id.textView7);

    TextView[] histos = {view1, view2, view3, view4, view5, view6, view7};

    Map<String, ?> allEntries = msharedPreferences.getAll();

    String dayNumberKey = android.text.format.DateFormat.format("yyyyMMddhms", new java.util.Date()).toString();

    int myCol = msharedPreferences.getInt(dayNumberKey, currenMood);

    if (myCol == 0){
        currentColor = 0;
    }
    else if (myCol == 1){
        currentColor = 1;
    }
    else if (myCol == 2){
        currentColor = 2;
    }
    else if (myCol == 3){
        currentColor = 3;
    }
    else if (myCol == 4){
        currentColor = 4;
    }

    int i = 0;

    for (Map.Entry<String, ?> entry : allEntries.entrySet()) {
        histos[i].setText(entry.getValue().toString());
        i++;
        if(i > 6) break;
        histos[i].setBackgroundResource(tableColor[currentColor]);
    }
}

}

Voilà，我真的很想了解为什么当我单击历史记录按钮时为什么只显示红色。我敢肯定这有点少，但是正如我所说，我是一个初学者。

谢谢！

解决方案：我删除了尝试在不同位置使用不同值的动态密钥

Answer 1

您正在使用当前日期和时间作为键来存储颜色，并使用另一个日期和时间来检索颜色。 android.text.format.DateFormat.format("yyyyMMddhms", new java.util.Date()).toString()的两次调用的返回值将不同。使用相同的值（常数值）存储和检索要使用的数据。

Java中Android Studio上的问题映射

1 个答案: