Swt/Jface tableViewer入门教程二（让TableViewer按照列排序)

有一个功能是我们常使用的，就是在列的头上点击一下，整个表的记录按照这个列来排序，再点击一下按照这个列的反序来排序。那JFace是如何实现这个功能的呢？
在JFace中是通过一个排序器来实现的，就是ViewerSorter下边写出详细的步骤
一、定义一个sorter继承自ViewerSorter

importjava.util.Date;

importorg.eclipse.jface.viewers.Viewer;
importorg.eclipse.jface.viewers.ViewerSorter;

publicclassSorterextendsViewerSorter{
privatestaticfinalintID=1;
privatestaticfinalintNAME=2;
privatestaticfinalintSEX=3;
privatestaticfinalintAGE=4;
privatestaticfinalintCREATE_DATE=5;

publicstaticfinalSorterID_ASC=newSorter(ID);
publicstaticfinalSorterID_DESC=newSorter(-ID);
publicstaticfinalSorterNAME_ASC=newSorter(NAME);
publicstaticfinalSorterNAME_DESC=newSorter(-NAME);
publicstaticfinalSorterSEX_ASC=newSorter(SEX);
publicstaticfinalSorterSEX_DESC=newSorter(-SEX);
publicstaticfinalSorterAGE_ASC=newSorter(AGE);
publicstaticfinalSorterAGE_DESC=newSorter(-AGE);
publicstaticfinalSorterCREATE_DATE_ASC=newSorter(CREATE_DATE);
publicstaticfinalSorterCREATE_DATE_DESC=newSorter(-CREATE_DATE);

privateintsortType;
privateSorter(intsortType){
this.sortType=sortType;
}
publicintcompare(Viewerviewer,Objecte1,Objecte2){
Peoplep1=(People)e1;
Peoplep2=(People)e2;
switch(sortType){
caseID:{
Longl1=p1.getId();
Longl2=p2.getId();
returnl1.compareTo(l2);
}
case-ID:{
Longl1=p1.getId();
Longl2=p2.getId();
returnl2.compareTo(l1);
}
caseNAME:{
Strings1=p1.getName();
Strings2=p2.getName();
returns1.compareTo(s2);
}
case-NAME:{
Strings1=p1.getName();
Strings2=p2.getName();
returns2.compareTo(s1);
}
caseSEX:{
Strings1=p1.getSex();
Strings2=p2.getSex();
returns1.compareTo(s2);
}
case-SEX:{
Strings1=p1.getSex();
Strings2=p2.getSex();
returns2.compareTo(s1);
}
caseAGE:{
Integeri1=p1.getAge();
Integeri2=p2.getAge();
returni1.compareTo(i2);
}
case-AGE:{
Integeri1=p1.getAge();
Integeri2=p2.getAge();
returni2.compareTo(i1);
}
caseCREATE_DATE:{
Dated1=p1.getCreateDate();
Dated2=p2.getCreateDate();
d1.compareTo(d2);
}
case-CREATE_DATE:{
Dated1=p1.getCreateDate();
Dated2=p2.getCreateDate();
d2.compareTo(d1);
}
}
return0;
}
}

二、在TableViewer上，为每一列加入事件监听器类似这样的结构

newColumnTableColumn.addSelectionListener(newSelectionAdapter(){
booleanasc=true;
publicvoidwidgetSelected(SelectionEvente){
tableViewer.setSorter(asc?Sorter.ID_ASC:Sorter.ID_DESC);
asc=!asc;
}
});

都加入后TestTableViewer的结果：

importorg.eclipse.jface.viewers.TableViewer;
importorg.eclipse.swt.SWT;
importorg.eclipse.swt.events.SelectionAdapter;
importorg.eclipse.swt.events.SelectionEvent;
importorg.eclipse.swt.layout.FillLayout;
importorg.eclipse.swt.widgets.Display;
importorg.eclipse.swt.widgets.Shell;
importorg.eclipse.swt.widgets.Table;
importorg.eclipse.swt.widgets.TableColumn;

publicclassTestTableViewer{
privatestaticTabletable;
/***//**
*Launchtheapplication
*@paramargs
*/
publicstaticvoidmain(String[]args){
finalDisplaydisplay=Display.getDefault();
finalShellshell=newShell();
shell.setSize(500,375);
shell.setText("SWTApplication");
//
finalTableViewertableViewer=newTableViewer(shell,SWT.CHECK|SWT.MULTI|SWT.FULL_SELECTION|SWT.BORDER|SWT.V_SCROLL|SWT.H_SCROLL);

table=tableViewer.getTable();
table.setLinesVisible(true);
table.setHeaderVisible(true);
table.setBounds(97,79,373,154);

finalTableColumnnewColumnTableColumn=newTableColumn(table,SWT.NONE);
newColumnTableColumn.setWidth(39);
newColumnTableColumn.setText("ID");
//加入事件监听器
newColumnTableColumn.addSelectionListener(newSelectionAdapter(){
booleanasc=true;
publicvoidwidgetSelected(SelectionEvente){
tableViewer.setSorter(asc?Sorter.ID_ASC:Sorter.ID_DESC);
asc=!asc;
}
});

finalTableColumnnewColumnTableColumn_1=newTableColumn(table,SWT.NONE);
newColumnTableColumn_1.setWidth(85);
newColumnTableColumn_1.setText("姓名");
//加入事件监听器
newColumnTableColumn_1.addSelectionListener(newSelectionAdapter(){
booleanasc=true;
publicvoidwidgetSelected(SelectionEvente){
tableViewer.setSorter(asc?Sorter.NAME_ASC:Sorter.NAME_DESC);
asc=!asc;
}
});

finalTableColumnnewColumnTableColumn_2=newTableColumn(table,SWT.NONE);
newColumnTableColumn_2.setWidth(41);
newColumnTableColumn_2.setText("性别");
//加入事件监听器
newColumnTableColumn_2.addSelectionListener(newSelectionAdapter(){
booleanasc=true;
publicvoidwidgetSelected(SelectionEvente){
tableViewer.setSorter(asc?Sorter.SEX_ASC:Sorter.SEX_DESC);
asc=!asc;
}
});

finalTableColumnnewColumnTableColumn_3=newTableColumn(table,SWT.NONE);
newColumnTableColumn_3.setWidth(43);
newColumnTableColumn_3.setText("年龄");
//加入事件监听器
newColumnTableColumn_3.addSelectionListener(newSelectionAdapter(){
booleanasc=true;
publicvoidwidgetSelected(SelectionEvente){
tableViewer.setSorter(asc?Sorter.AGE_ASC:Sorter.AGE_DESC);
asc=!asc;
}
});

finalTableColumnnewColumnTableColumn_4=newTableColumn(table,SWT.NONE);
newColumnTableColumn_4.setWidth(126);
newColumnTableColumn_4.setText("创建日期");
//加入事件监听器
newColumnTableColumn_4.addSelectionListener(newSelectionAdapter(){
booleanasc=true;
publicvoidwidgetSelected(SelectionEvente){
tableViewer.setSorter(asc?Sorter.CREATE_DATE_ASC:Sorter.CREATE_DATE_DESC);
asc=!asc;
}
});

tableViewer.setContentProvider(newContentProvider());
tableViewer.setLabelProvider(newTableLabelProvider());
tableViewer.setInput(People.getPeople());

shell.open();
shell.setLayout(newFillLayout());
shell.layout();
while(!shell.isDisposed()){
if(!display.readAndDispatch())
display.sleep();
}
}
}

试一下结果是不是出来了？
好了，最后解释几点：
1，sorter中利用了jdk的compareTo来实现比较，当然你也可以根据自己的需求来实现。
2, sorter中利用了"-"符号来得到正负数字，用来表现升序、降序。
source下载：http://www.blogjava.net/Files/dreamstone/jface-2.rar