如何使用共享首选项保存在微调器上和从选中的单选按钮中选择的数据

Question

我试图将用户从微调器中选择的内容保存到共享的首选项对象中，并且还保存选中了哪个单选按钮（正值或负值）。 然后显示或从共享首选项对象检索数据。

这是我的onCreate方法的样子：

public class ShoulderActivity extends Activity implements OnItemSelectedListener {
    
    
        
// The attribute used to store the value of the special test id <= used in sharedPreferences
       
        
    int selectedPosition;
    
        

// The attribute used to store the value (positive or negative) that correspond to the special test id <= used in sharedPreferences
        
    EditText STValue;
    
        
    TextView STNameTextView, STValueTextView;
    
        

public static final String DEFAULT = "N/A";
    

@Override
    
protected void onCreate(Bundle savedInstanceState) 
{
        
    super.onCreate(savedInstanceState);
    
    setContentView(R.layout.shoulder_layout);
    
        
    Spinner shoulderSpinner = (Spinner) findViewById(R.id.shoulder_spinner);
    
        

    //Create an ArrayAdapter using the string array and a default spinner
    
    ArrayAdapter<CharSequence> shoulderAdapter = ArrayAdapter
               .createFromResource(this, R.array.shoulder_tests,
                         android.R.layout.simple_spinner_item);
    
        

    //Specify the layout to use when the list of choices appears
       
    shoulderAdapter
           .setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    
        

    //Apply the adapter to the spinner
       
    shoulderSpinner.setAdapter(shoulderAdapter);
    
         
    shoulderSpinner.setOnItemSelectedListener(this);
    
    
    

}//END onCreate

在下面，我写了add（）方法保存到共享首选项对象中：

public void add(View view)
{
    
        
    //User SharedPreferences to save the value per special test
        
    SharedPreferences sharedPref = getSharedPreferences("STData", Context.MODE_PRIVATE);
    
        
    //to edit the data or add data inside my file "STData"
         
    SharedPreferences.Editor editor = sharedPref.edit();
    
        
    //Store the values in my file "STData"
        

    // ******** pull up the name of the test from ONITEM selected on SPINNER **********
    
       
    //editor.putString("specialTestName", STName.getText().toString() );
        

    int selectedPosition = shoulderSpinner.getSelectedItemPosition()
          
    editor.putInt("specialTestName", selectedPosition);
        

    editor.commit();
    
        

    //**************************************
        

    // get this value from the Radio Button *****************
    
        
    RadioButton posValuerb1 = (RadioButton) findViewById(R.id.positiveId);
    
        
    // Save the test value; if positive test radio button is checked means test is positive and vice-versa
        
    editor.putBoolean("STValue", posValuerb1.isChecked());
    
    
        
    //To confirm the changes or to save them
        
    editor.commit();
    }

在我的display（）方法下面，用于从共享首选项对象检索和显示数据：

    // Method to Display special tests performed in the STData file
    
public void display(View view)
{
    
    
        
    // User SharedPreferences to save the value per special name    
    SharedPreferences sharedPref = getSharedPreferences("STData", Context.MODE_PRIVATE);
    
        
    shoulderSpinner.setSelection(sharedPref.getInt("spinnerSelection",0));
        

    //save special test Value in String 'testValue' <= entered by the PT
        
    String testValue = sharedPref.getString("STValue", DEFAULT);
    
    
        

    // DISPlAY THE VALUES ON THE SCREEN OF ACTIVITY !!!!


        // Test Name
        
    STNameTextView = (TextView) findViewById(R.id.STView3);
         
    STNameTextView.setText(testName);
    
        // Name of the Special Test
         
    STValueTextView = (TextView) findViewById(R.id.STView4);
         
    STValueTextView.setText(testValue);
    }

}

Answer 1

您显然误解了SharedPreference类的工作方式。 由于您决定使用键“ specialTestName”保留一个int值，因此应按以下方式检索它，以获取保存的int：

int selectedPosition = sharedPrefObj.getInt("specialTestName", DEFAULTINT);

同样，您从复选框中保存的是布尔值，因此您无法尝试以String形式进行检索。

boolean checkValue = sharedPrefObj.getBoolean("STValue", DEFAULTBOOLEAN);

顺便说一句，我强烈建议您创建一个与SharedPreference直接交互的类，而不是直接在Activity / Fragment中使用它。

希望这对您有所帮助。