Question

如何修剪此代码？

    prefsDisplay = getSharedPreferences("spinnerSelection",
            Context.MODE_PRIVATE);
    prefsPlan = getSharedPreferences("spinnerSelection1",
            Context.MODE_PRIVATE);

    if (prefsDisplay.getInt("spinnerSelection", 0) == 0) {
        s1 = 0;
    } else if (prefsDisplay.getInt("spinnerSelection", 0) == 1) {
        s1 = 1;
    } else if (prefsDisplay.getInt("spinnerSelection", 0) == 2) {
        s1 = 2;
    } else if (prefsDisplay.getInt("spinnerSelection", 0) == 3) {
        s1 = 3;
    } else {
        s1 = 0;
        DP.BreakdownMonths = 0;
    }

    if (prefsPlan.getInt("spinnerSelection1", 0) == 0) {
        s2 = 0;
    } else if (prefsPlan.getInt("spinnerSelection1", 0) == 1) {
        s2 = 1;
    } else if (prefsPlan.getInt("spinnerSelection1", 0) == 2) {
        s2 = 2;
    } else {
        s2 = 0;
        DP.PlanType = "highint";
    }

基本上，我正在做什么，当应用程序登录时，我希望它检查SharedPreferences。如果找到一个值，它会分配一个值，否则，它默认为一个值。

Answer 1

以下内容与您的代码完全相同。使用分配给共享首选项的值，如果为空，则分配0并分配DP。

prefsDisplay = getSharedPreferences("spinnerSelection",
        Context.MODE_PRIVATE);
prefsPlan = getSharedPreferences("spinnerSelection1",
        Context.MODE_PRIVATE);

s1 = prefsDisplay.getInt("spinnerSelection", -1 );
if( s1 < 0 ) { 
    s1 = 0;
    DP.BreakdownMonths = 0;
}

s2 = prefsPlan.getInt("spinnerSelection1", -1 );
if( s2 < 0 ) {
    s2 = 0;
    DP.PlanType = "highint";
}

Answer 2

使用switch和case定义相应的if语句，并使用default分配它是否与任何if语句都匹配。

示例：

   int month = 8;
    String monthString;
    switch (month) {
        case 1:  monthString = "January";
                 break;
        case 2:  monthString = "February";
                 break;
        case 3:  monthString = "March";
                 break;
        case 4:  monthString = "April";
                 break;
        case 5:  monthString = "May";
                 break;
        case 6:  monthString = "June";
                 break;
        case 7:  monthString = "July";
                 break;
        case 8:  monthString = "August";
                 break;
        case 9:  monthString = "September";
                 break;
        case 10: monthString = "October";
                 break;
        case 11: monthString = "November";
                 break;
        case 12: monthString = "December";
                 break;
        default: monthString = "Invalid month";
                 break;
    }
    System.out.println(monthString);

简化代码以管理SharedPreferences

2 个答案: