我正在使用自定义对话框首选项在我的首选项菜单中生成搜索栏。在研究了 seekbar 的实现之后，为了从 seekbar 中获取我需要的浮点值，我编写了以下代码：
public void onProgressChanged(SeekBar seek, int newValue,
boolean fromTouch) {
// Round the value to the closest integer value.
if (stepSize >= 1) {
value = Math.round(newValue/stepSize)*stepSize;
}
else {
value = newValue;
}
// Set the valueText text.
float sValue = newValue*10;
sValue = sValue/100;
valueText.setText(Float.toString(sValue));
这会产生我想要的浮动。但是，我希望能够在我的主要活动中使用这个浮动。我尝试使用 SharedPreferences 存储它：
userPrefs = PreferenceManager.getDefaultSharedPreferences(getBaseContext());
Editor editor = userPrefs.edit()
editor.putFloat("mpm", sValue);
editor.commit();
这就是我学会在扩展 Activity 的类中使用 SharedPreferences 的方式。
但是，由于此搜索栏扩展了对话首选项，我无法使用
getBaseContext()
当我收到该类型的方法 getBaseContext 未定义的错误时。
我曾尝试将 getBaseContext() 更改为 getContext() 但这并不成功，尽管这可能是因为我不熟悉此实现。
如何从对话首选项中保存此浮点数并在不同的类中使用该值？
我用来检索 SharedPreferences 的代码：
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.logbook);
initialise();
userPrefs = PreferenceManager.getDefaultSharedPreferences(getBaseContext());
list = userPrefs.getString("list", "10");
userswallstring = userPrefs.getString("height", "10.0");
try {
usersWall = Float.valueOf(userswallstring.trim());
} catch (Exception e) {
// TODO: handle exception
}
mpm = userPrefs.getFloat("mpm", 2);
Mpm.class：包com.gbclimber.ep；
import android.content.Context;
import android.content.DialogInterface;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.content.res.TypedArray;
import android.preference.DialogPreference;
import android.preference.PreferenceManager;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.SeekBar;
import android.widget.TextView;
public class Mpm extends
DialogPreference implements SeekBar.OnSeekBarChangeListener {
// Layout widgets.
private SeekBar seekBar = null;
private TextView valueText = null;
// Custom xml attributes.
private int maximumValue = 0;
private int minimumValue = 0;
private int stepSize = 0;
private String units = null;
private int value = 0;
SharedPreferences userPrefs;
/**
* The SeekBarDialogPreference constructor.
* @param context of this preference.
* @param attrs custom xml attributes.
*/
public Mpm(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray typedArray = context.obtainStyledAttributes(attrs,
R.styleable.Mpm);
maximumValue = typedArray.getInteger(
R.styleable.Mpm_maximumValue, 0);
minimumValue = typedArray.getInteger(
R.styleable.Mpm_minimumValue, 0);
stepSize = typedArray.getInteger(
R.styleable.Mpm_stepSize, 1);
units = typedArray.getString(
R.styleable.Mpm_units);
typedArray.recycle();
}
/**
* {@inheritDoc}
*/
protected View onCreateDialogView() {
LayoutInflater layoutInflater = LayoutInflater.from(getContext());
View view = layoutInflater.inflate(
R.layout.mpmdp, null);
seekBar = (SeekBar)view.findViewById(R.id.seekbar);
valueText = (TextView)view.findViewById(R.id.valueText);
// Get the persistent value and correct it for the minimum value.
value = getPersistedInt(minimumValue) - minimumValue;
// You're never know...
if (value < 0) {
value = 0;
}
seekBar.setOnSeekBarChangeListener(this);
seekBar.setKeyProgressIncrement(stepSize);
seekBar.setMax(maximumValue - minimumValue);
seekBar.setProgress(value);
return view;
}
/**
* {@inheritDoc}
*/
public void onProgressChanged(SeekBar seek, int newValue,
boolean fromTouch) {
// Round the value to the closest integer value.
if (stepSize >= 1) {
value = Math.round(newValue/stepSize)*stepSize;
}
else {
value = newValue;
}
// Set the valueText text.
float sValue = newValue*10;
sValue = sValue/100;
userPrefs = PreferenceManager
.getDefaultSharedPreferences(getContext());
Editor editor = userPrefs.edit();
editor.putFloat("mpm", sValue);
editor.commit();
valueText.setText(Float.toString(sValue));
callChangeListener(value);
}
/**
* {@inheritDoc}
*/
public void onStartTrackingTouch(SeekBar seek) {
}
/**
* {@inheritDoc}
*/
public void onStopTrackingTouch(SeekBar seek) {
}
/**
* {@inheritDoc}
*/
public void onClick(DialogInterface dialog, int which) {
// if the positive button is clicked, we persist the value.
if (which == DialogInterface.BUTTON_POSITIVE) {
if (shouldPersist()) {
persistInt(value + minimumValue);
}
}
super.onClick(dialog, which);
}
@Override
protected void onDialogClosed(boolean positiveResult) {
// TODO Auto-generated method stub
super.onDialogClosed(positiveResult);
persistInt(value + minimumValue);
}
}