Question

我想在设置首选项对话框中选择它后获取值。但是我得到ClassCastException并且崩溃了？可能是因为我不确定如何获得已选择的值并将其保存。基本上我需要能够在另一个Activity中获得新值。您如何获得这些价值并保存并能够在其他活动中找到它们？

 public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {

        SharedPreferences s = getSharedPreferences("MY_PREFS", 0);

        // Create a editor to edit the preferences:
        SharedPreferences.Editor editor = s.edit();

 if (key.equals("language_key")) {

       sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
       ListPreference listPref = (ListPreference) sharedPreferences; 
       String entryvalue = (String) listPref.getEntry();

        if (entryvalue == "EN")
        {
            Log.d(TAG, "EN" + entryvalue);
            Toast.makeText(getBaseContext(), "true", Toast.LENGTH_SHORT).show();
        }
        else
        {
            Log.d(TAG, "else" + entryvalue);
            Toast.makeText(getBaseContext(), "false", Toast.LENGTH_SHORT).show();
            }



       }
}

首选项xml文件

<ListPreference 
            android:key="language_key"
            android:summary="Choice of language mode"
            android:title="Language Mode"
            android:defaultValue="CH"
            android:entries="@array/Languages"
        android:entryValues="@array/LanguageValues"   />

array.xml

<string-array name="Languages">
    <item name="EN">English</item>
    <item name="CH">Chinese</item>
    <item name="SP">Spanish</item>
</string-array>

<string-array name="LanguagesValues">
    <item name="EN">EN</item>
    <item name="CH">CH</item>
    <item name="SP">SP</item>
</string-array>

Answer 1

sharedPreferences无法转换为ListPreferences。要获取价值，请调用getString方法：

sharedPreferences.getString( "language_key", "");

Android在ListPreference上崩溃

1 个答案: