onPause和onResume方法使用sharedPreferences

Question

所以我試圖保存我的SeekBar值onPause，然後讓他們重新出現onResume。我的代碼有效，但由於某種原因，只有列表中的第一個被保存。如果我改變了紅色的SeekBar，然後保存但沒有別的，如果我在0處留下紅色並將綠色移動到40，那麼綠色將會保存，但如果我改變紅色，只有紅色會保存。我不知道爲什麼會發生這種情況。我必須使用onResume或onPause，否則我會使我的變量變爲靜態的。

import android.content.SharedPreferences; 
import android.support.v7.app.ActionBarActivity; 
import android.os.Bundle; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.view.View; 
import android.widget.SeekBar; 
import android.widget.TextView; 
import android.widget.SeekBar.OnSeekBarChangeListener; 
import android.graphics.Color; 



public class ColorChooserActivity extends ActionBarActivity 
implements OnSeekBarChangeListener { 

    // define variables for the widgets 
    private SeekBar redSeekBar; 
    private SeekBar greenSeekBar; 
    private SeekBar blueSeekBar; 
    private SeekBar alphaSeekBar; 
    private View colorView; 
    private TextView colorTextView; 

    //instance variable 
    private int colorValue = 0; 
    private int redValue = 0; 
    private int greenValue = 0; 
    private int blueValue = 0; 
    private int alphaValue = 0; 
    private String output; 

    // define the SharedPreferences object 
    private SharedPreferences savedValues; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_color_chooser); 

     // get references to the widgets 
     redSeekBar = (SeekBar) findViewById(R.id.redSeekBar); 
     greenSeekBar = (SeekBar) findViewById(R.id.greenSeekBar); 
     blueSeekBar = (SeekBar) findViewById(R.id.blueSeekBar); 
     alphaSeekBar = (SeekBar) findViewById(R.id.alphaSeekBar); 
     colorView = (View) findViewById(R.id.colorView); 
     colorTextView = (TextView) findViewById(R.id.colorTextView); 

     // add listeners 
     redSeekBar.setOnSeekBarChangeListener(this); 
     greenSeekBar.setOnSeekBarChangeListener(this); 
     blueSeekBar.setOnSeekBarChangeListener(this); 
     alphaSeekBar.setOnSeekBarChangeListener(this); 

     // get SharedPreferences object 
     savedValues = getSharedPreferences("SavedValues", MODE_PRIVATE); 

    } 


    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.menu_color_chooser, menu); 
     return true; 
    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     // Handle action bar item clicks here. The action bar will 
     // automatically handle clicks on the Home/Up button, so long 
     // as you specify a parent activity in AndroidManifest.xml. 
     int id = item.getItemId(); 

     //noinspection SimplifiableIfStatement 
     if (id == R.id.action_settings) { 
      return true; 
     } 

     return super.onOptionsItemSelected(item); 
    } 

    @Override 
    public void onPause() { 
     // save the instance variables 
     SharedPreferences.Editor editor = savedValues.edit(); 
     editor.putInt("redValue", redValue); 
     editor.putInt("greenValue", greenValue); 
     editor.putInt("blueValue", blueValue); 
     editor.putInt("alphaValue", alphaValue); 
     editor.putInt("colorValue", colorValue); 
     editor.putString("output", output); 
     editor.commit(); 

     super.onPause(); 
    } 

    @Override 
    public void onResume() { 

     //get the instance variables 
     redValue = savedValues.getInt("redValue", redValue); 
     greenValue = savedValues.getInt("greenValue", greenValue); 
     blueValue = savedValues.getInt("blueValue", blueValue); 
     alphaValue = savedValues.getInt("alphaValue", alphaValue); 
     colorValue = savedValues.getInt("colorValue", colorValue); 
     output = savedValues.getString("output", output); 



     // set widgets 
     colorView.setBackgroundColor(colorValue); 
     colorTextView.setText(output); 
     redSeekBar.setProgress(redValue); 
     greenSeekBar.setProgress(greenValue); 
     blueSeekBar.setProgress(blueValue); 
     alphaSeekBar.setProgress(alphaValue); 

     super.onResume(); 

    } 

    // argb method 
    public int argb(int a, int r, int g, int b){ 
     return Color.argb(a, r, g, b); 
    } 

    //***************************************************** 
    // Event handler for the SeekBar 
    //***************************************************** 
    @Override 
    public void onStartTrackingTouch(SeekBar seekBar) { 
    } 

    @Override 
    public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) 
    { 
     redValue = redSeekBar.getProgress(); 
     greenValue = greenSeekBar.getProgress(); 
     blueValue = blueSeekBar.getProgress(); 
     alphaValue = alphaSeekBar.getProgress(); 

     colorValue = argb(alphaValue, redValue, greenValue, blueValue); 

     colorView.setBackgroundColor(colorValue); 

     output = "Red: " + redValue + " Green: " + greenValue + 
       " Blue: " + blueValue + " Alpha: " + alphaValue; 

     colorTextView.setText(output); 
    } 

    @Override 
    public void onStopTrackingTouch(SeekBar seekBar){ 
    } 


} 

Answer 1

我認爲問題出在您的onProgressChanged方法中。你有幾個搜索條，我建議你爲它們中的每一個實現一個單獨的OnSeekBarChangeListener或者在保存它的值之前檢查搜索條的ID。

基本上，你應該有這樣的事情在你的onCreate方法（基於SO用戶的評論你的問題）：

@Override 
public void onProgressChanged(SeekBar seekBar, int progress, 
     boolean fromUser) { 


    switch (seekBar.getId()) { 
    case R.id.redSeekBar: 
     redValue = redSeekBar.getProgress(); 
     break; 
    case R.id.greenSeekBar: 
     greenValue = greenSeekBar.getProgress(); 
     break; 
    case R.id.blueSeekBar: 
     blueValue = blueSeekBar.getProgress(); 
     break; 
    case R.id.alphaSeekBar: 
     alphaValue = alphaSeekBar.getProgress(); 
     break; 
    } 

    colorValue = argb(alphaValue, redValue, greenValue, blueValue); 

    colorView.setBackgroundColor(colorValue); 

    output = "Red: " + redValue + " Green: " + greenValue + " Blue: " 
      + blueValue + " Alpha: " + alphaValue; 

    colorTextView.setText(output); 
} 

我希望這有助於。