Question

我在一个活动中创建了共享偏好。该值已存储但当我尝试在另一个活动中访问它时，它只返回默认值。知道我的代码有什么问题吗？

活动1：

        public static final String MyPREFERENCES = "MyPrefs" ;
        public static final String Monday = "monkey";
        public static final String Tuesday = "tuekey";
        public static final String Wednesday = "wedkey";
        public static final String Thursday = "thukey";
        public static final String Friday = "frikey";
        public static final String Saturday = "satkey";
        public static final String Sunday = "sunkey";



            sharedPreferences = getSharedPreferences(MyPREFERENCES, Context.MODE_PRIVATE);   

      String start = ed_start.getText().toString();
            String end = ed_end.getText().toString();

            Calendar c1 = Calendar.getInstance();
            int dd1 = Integer.parseInt(start.substring(0, 2));
            int mm1 = Integer.parseInt(start.substring(3, 5));
            int yy1 = Integer.parseInt(start.substring(6,8));
            c1.set(yy1, mm1, dd1);


            Calendar c2 = Calendar.getInstance();
            int dd2 = Integer.parseInt(end.substring(0, 2));
            int mm2 = Integer.parseInt(end.substring(3, 5));
            int yy2 = Integer.parseInt(end.substring(6,8));
            c2.set(yy2, mm2, dd2);

            int mon = 0;
            int tue = 0;
            int wed = 0;
            int thu = 0;
            int fri = 0;
            int sat = 0;
            int sun = 0;
            c2.add(Calendar.DATE,1);

            while(c2.after(c1)) {
                if(c1.get(Calendar.DAY_OF_WEEK)==Calendar.MONDAY)
                    mon++;
                if(c1.get(Calendar.DAY_OF_WEEK)==Calendar.TUESDAY)
                    tue++;
                if(c1.get(Calendar.DAY_OF_WEEK)==Calendar.WEDNESDAY)
                    wed++;
                if(c1.get(Calendar.DAY_OF_WEEK)==Calendar.THURSDAY)
                    thu++;
                if(c1.get(Calendar.DAY_OF_WEEK)==Calendar.FRIDAY)
                    fri++;
                if(c1.get(Calendar.DAY_OF_WEEK)==Calendar.SATURDAY)
                    sat++;
                if(c1.get(Calendar.DAY_OF_WEEK)==Calendar.SUNDAY)
                    sun++;
                c1.add(Calendar.DATE,1);
            }

              SharedPreferences.Editor editor = sharedPreferences.edit();
            editor.putString(Start, start);
            editor.putString(End,end);
            editor.putInt(Monday,mon);
            editor.putInt(Tuesday,tue);
            editor.putInt(Wednesday,wed);
            editor.putInt(Thursday,thu);
            editor.putInt(Friday,fri);
            editor.putInt(Saturday,sat);
            editor.putInt(Sunday,sun);

            editor.commit();

活动2：

    public static final String MyPREFERENCES = "MyPrefs" ;
    public static final String Monday = "monkey";
public static final String Tuesday = "tuekey";
public static final String Wednesday = "wedkey";
public static final String Thursday = "thukey";
public static final String Friday = "frikey";
public static final String Saturday = "satkey";
public static final String Sunday = "sunkey";


        sharedPreferences = getSharedPreferences(MyPREFERENCES, Context.MODE_PRIVATE);
        int k =0;
        int tot = 0;
        for(;k<strings.length;) {
            if(strings[k].equals("Mon")){
                System.out.println("Moday ent");
                System.out.println(sharedPreferences.getInt("Monday",-1 ));
                tot = tot + sharedPreferences.getInt(Monday, 0); }
            if(strings[k].equals("Tue")) {
                System.out.println("tue ent");
                tot = tot + sharedPreferences.getInt(Tuesday,0);}
            if (strings[k].equals("Wed")) {
                System.out.println("wedday ent");
                tot = tot + sharedPreferences.getInt(Wednesday,0); }
            if (strings[k].equals("Thu"))
                tot = tot + sharedPreferences.getInt(Thursday,0);
            if (strings[k].equals("Fri"))
                tot = tot + sharedPreferences.getInt(Friday,0);
            if(strings[k].equals("Sat"))
                tot = tot + sharedPreferences.getInt(Saturday,0);
            if (strings[k].equals("Sun"))
                tot = tot + sharedPreferences.getInt(Sunday, 0);
            k = k+4;
        }
        System.out.println("tot: " + tot);
        tot = (int)((float)tot*(per/100));

Answer 1

如果您在SharedPrefs输入值，则需要使用键值格式，这意味着键需要使用引号...如下所示：

editor.putString("Start", start);

你没有使用引号......

当你在getInt()中找回它时（你已经在那里正确地完成了它）。

祝你好运！

编辑：

在你的第一个活动中，你给出的Constant键值等于：＆＃34; monkey＆＃34;，＆＃34; tuekey＆＃34;等等。

在你的第二个活动中，你用＃34;星期一＆＃34;，星期二和＃34;的关键值来呼叫他们。等等。因此，值不同，您将获得默认值

Answer 2

您可以像这样设置sharedPreferences的值：

          public static final String Monday = "monkey";
    public static final String Tuesday = "tuekey";
    public static final String Wednesday = "wedkey";
    public static final String Thursday = "thukey";
    public static final String Friday = "frikey";
    public static final String Saturday = "satkey";
    public static final String Sunday = "sunkey";

并使用

检索它们

    "Monday"
    "Tuesday"
    "Wednesday"
       .
       .
      etc

这个值必须相等。所以你必须检索它们，例如：

    sharedPreferences.getInt("monkey",0);}

或者您必须在您的活动中设置值，如：

    public static final String Monday = "Monday";

Answer 3

您的密钥错误：活动1

 public static final String Monday = "monkey";

活动2：

if(strings[k].equals("Mon")){
            System.out.println("Moday ent");
            System.out.println(sharedPreferences.getInt("Monday",-1 ));
            tot = tot + sharedPreferences.getInt("Monday", 0); }

见这一行：

getInt("Monday",-1 ));

应该是：

getInt("monkey",-1 ));//similarly for all the fields

当您使用公共静态final String时，您可以使用所有键：

ClassName.MONDAY //this is what I always do no chance for key errors

sharedpreferences.getInt（）在另一个活动中调用时给出默认值

3 个答案: