在我的應用程序中,我試圖將鍵值保存爲零或一個,具體取決於是否選中了複選框。我在不同的活動中檢索這些值。然而,當我嘗試檢索的價值,我得到一個空字符串:鍵值存儲數據未檢索
在活動1保存鍵值(ScienceCoursesCheck):
public void setDefaults(String key, String value) {
SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(this);
SharedPreferences.Editor editor = sharedPref.edit();
editor.putString(key, value);
editor.commit();
}
public void onCheckboxClicked(View view) {
// Is the view now checked?
boolean checked = ((CheckBox) view).isChecked();
// Check which checkbox was clicked
switch(view.getId()) {
case R.id.checkBox_APBio:
if (checked) {
setDefaults("APBio", "1");
}
else {
setDefaults("APBio", "0");
break;
}
}}
在活動2檢索鍵值(是MyHome):
public static String getDefaults(String key, Context context) {
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
return preferences.getString(key, null);
}
public void myMethod() {
SharedPreferences myPrefs = getSharedPreferences("ScienceCoursesCheck", MODE_PRIVATE);
String APBio = myPrefs.getString("APBio","");
if (APBio.equals("1")){
Button myButton = new Button(this);
myButton.setText(APBio);
RelativeLayout ll = (RelativeLayout)findViewById(R.id.activity_my_home);
RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
ll.addView(myButton, lp);
}
}
第二項活動是否訪問正確的SharedPreferences文件?