Eclipse RCP 中创建自己定义首选项，并能读取首选项中的值

Eclipse RCP的插件中若想自定义首选项须要扩展扩展点：

org.eclipse.core.runtime.preferences //该扩展点用于初始化首选项中的值

org.eclipse.ui.preferencePages//该扩展点用于定义自己的首选项页面

plugin.xml中内容如：

Database Preferences挂在WorkFlowBase下。须要在category中填写workFlowBase的ID

WorkFlowPreferenceInitializer类。用于初始化首选项中的值

import org.eclipse.core.runtime.preferences.AbstractPreferenceInitializer;
import org.eclipse.jface.preference.IPreferenceStore;
import mydesigner.WorkFlowActivator;
/**
 * Class used to initialize default preference values.
 * 首选项的初始化
 */
public class WorkFlowPreferenceInitializer extends AbstractPreferenceInitializer {

  /*
   * (non-Javadoc)
   * 
   * @see org.eclipse.core.runtime.preferences.AbstractPreferenceInitializer#initializeDefaultPreferences()
   */
  public void initializeDefaultPreferences() {
    IPreferenceStore store = WorkFlowActivator.getDefault().getPreferenceStore();
    store.setDefault(WorkFlowPreferenceConstants.P_BOOLEAN, true);
    store.setDefault(WorkFlowPreferenceConstants.P_CHOICE, "choice2");
    store.setDefault(WorkFlowPreferenceConstants.P_STRING,"Default value");
    store.setDefault(WorkFlowPreferenceConstants.USER_NAME, "admin");
    store.setDefault(WorkFlowPreferenceConstants.PASSWORD, "123456");//页面上的初始值
  }
}

WorkFlowPreferenceConstants 该类定义了首选项中的常量

public class WorkFlowPreferenceConstants {

  public static final String P_PATH = "pathPreference";

  public static final String P_BOOLEAN = "booleanPreference";

  public static final String P_CHOICE = "choicePreference";

  public static final String P_STRING = "stringPreference";

  public static final String USER_NAME ="userName"; 

  public static final String PASSWORD = "passWord";

}

WorkFlowBasePreferencePage该类定义了首选项中的workFlow页面

import mydesigner.WorkFlowActivator;

import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.preference.PreferencePage;
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Text;
import org.eclipse.ui.IWorkbench;
import org.eclipse.ui.IWorkbenchPreferencePage;

import com.workflow.preferences.WorkFlowPreferenceConstants;
/**
 * 首选项中的workFlow页面
 * @author lww
 *
 */
public class WorkFlowBasePreferencePage extends PreferencePage implements IWorkbenchPreferencePage{

  private Text userName; //username
  private Text password; //密码框

  public WorkFlowBasePreferencePage() {
    super();
    setPreferenceStore(WorkFlowActivator.getDefault().getPreferenceStore());
    setDescription("This is a workflowBase PreferencePage!");
  }
  @Override
  public void init(IWorkbench workbench) {

  }
  //该方法为必须实现的方法，在此方法中创建页面上的各种控件 
  @Override
  protected Control createContents(Composite parent) {
     Composite composite = new Composite(parent, SWT.NONE); 
     composite.setLayout(new GridLayout(2, false)); 
     //获取保存此页面的PreferenceStore对象 
     IPreferenceStore preferenceStore = getPreferenceStore(); 

     new Label(composite, SWT.LEFT).setText("登录username:"); 
     userName = new Text(composite, SWT.BORDER); 
     userName.setLayoutData(new GridData(GridData.FILL_HORIZONTAL)); 
     //设置username为保存在文件里的值 
     userName.setText(preferenceStore.getString(WorkFlowPreferenceConstants.USER_NAME)); 

     new Label(composite, SWT.LEFT).setText("登陆password:"); 
     password = new Text(composite, SWT.BORDER); 
     password.setEchoChar('*'); //设置密码用*显示
     password.setLayoutData(new GridData(GridData.FILL_HORIZONTAL)); 
     //设置密码为保存在文件里的值 
     password.setText(preferenceStore.getString(WorkFlowPreferenceConstants.PASSWORD)); 
     return composite; 
  }
  /* 
  * 覆盖父类中的方法。但单击“恢复默认值”button时调用该方法 
  */ 
  protected void performDefaults() { 
     IPreferenceStore preferenceStore = getPreferenceStore(); 
     userName.setText( preferenceStore.getDefaultString(WorkFlowPreferenceConstants.USER_NAME)); 
     password.setText( preferenceStore.getDefaultString(WorkFlowPreferenceConstants.PASSWORD)); 
  } 
  /* 
  * 覆盖父类中的方法，但单击“应用”button时调用该方法 
  */ 
  public boolean performOk() { 
     IPreferenceStore preferenceStore = getPreferenceStore(); 
     if (userName != null) 
      preferenceStore.setValue(WorkFlowPreferenceConstants.USER_NAME, userName.getText()); 
     if (password != null) 
      preferenceStore.setValue(WorkFlowPreferenceConstants.PASSWORD, password.getText()); 
     return true; 
  } 
  @Override//用于扩展自己的button
  protected void contributeButtons(Composite parent) { 
     // super.contributeButtons(parent); 
     Button bt1 = new Button(parent, SWT.NONE); 
     bt1.setText("button一"); 
     ((GridLayout) parent.getLayout()).numColumns++; 
     Button bt2 = new Button(parent, SWT.NONE); 
     bt2.setText("button二"); 
     ((GridLayout) parent.getLayout()).numColumns++; 
  } 
}

DBPreferencePage该类定义了DB的首选项页面

import org.eclipse.jface.preference.*;
import org.eclipse.ui.IWorkbenchPreferencePage;
import org.eclipse.ui.IWorkbench;

import com.workflow.preferences.WorkFlowPreferenceConstants;

import mydesigner.WorkFlowActivator;

public class DBPreferencePage
  extends FieldEditorPreferencePage
  implements IWorkbenchPreferencePage {

  public DBPreferencePage() {
    super(GRID);
    setPreferenceStore(WorkFlowActivator.getDefault().getPreferenceStore());
    setDescription("A demonstration of a preference page implementation");
  }

  /**
   * Creates the field editors. Field editors are abstractions of
   * the common GUI blocks needed to manipulate various types
   * of preferences. Each field editor knows how to save and
   * restore itself.
   */
  public void createFieldEditors() {
    addField(new DirectoryFieldEditor(WorkFlowPreferenceConstants.P_PATH, 
        "&Directory preference:", getFieldEditorParent()));
    addField(
      new BooleanFieldEditor(
        WorkFlowPreferenceConstants.P_BOOLEAN,
        "&An example of a boolean preference",
        getFieldEditorParent()));

    addField(new RadioGroupFieldEditor(
        WorkFlowPreferenceConstants.P_CHOICE,
      "An example of a multiple-choice preference",
      1,
      new String[][] { { "&Choice 1", "choice1" }, {
        "C&hoice 2", "choice2" }
    }, getFieldEditorParent()));
    addField(
      new StringFieldEditor(WorkFlowPreferenceConstants.P_STRING, "A &text preference:", getFieldEditorParent()));
  }

  /* (non-Javadoc)
   * @see org.eclipse.ui.IWorkbenchPreferencePage#init(org.eclipse.ui.IWorkbench)
   */
  public void init(IWorkbench workbench) {
  }

}

运行结果如图：

设置的值会保存到

runtime-myDesigner.product\.metadata\.plugins\org.eclipse.core.runtime\.settings中会生成文件

MyDesigner.prefs（MyDesigner是当前的插件名）

若要读取该文件里的值：

//获取首选项中的值
    IPreferenceStore store = WorkFlowActivator.getDefault().getPreferenceStore();
    System.out.println("username：" + store.getString(WorkFlowPreferenceConstants.USER_NAME));
    System.out.println("密码：" + store.getString(WorkFlowPreferenceConstants.PASSWORD));//页面上的初始值

弹出相应的首选项对话框：

//将用户引导至首选项配置页面  
        PreferenceManager manager = PlatformUI.getWorkbench().getPreferenceManager();  
        Shell parentShell = PlatformUI.getWorkbench().getActiveWorkbenchWindow().getShell();  
        PreferenceDialog pd = new PreferenceDialog(parentShell, manager);  
        pd.setSelectedNode("com.workflow.preferences.page.DBPreferencePage");//设置选中的页面  (org.eclipse.ui.preferencePages 扩展点中page的ID)
        pd.open();

该对话框中没有搜索过滤栏。

还有一种实现：

PreferencesUtil.createPreferenceDialogOn(new Shell(), "com.workflow.preferences.page.DBPreferencePage", 
            new String[]{"com.workflow.preferences.page.WorkFlowBasePreferencePage","com.workflow.preferences.page.DBPreferencePage"}, null).open();

界面例如以下所看到的：

上面的new string 数组參数主要定义左边显示哪些首页项节点栏，若为null，就显示全部的所选项