在eclipse SWT中执行代码之前的setVisible（）

时间：2012-08-14 12:08:36

标签： java eclipse progress-bar swt

我想在执行某些代码之前通过ProgressBar设置SelectionListener。 但是，代码将被执行，但ProgressBar仍然不可见。

代码如下：

...
progressBar().setVisible(true);
parseFile(...);
...

public void parseFile(File file) {
    System.out.println("Parsing File: " + file);
    BufferedReader br = null;
    BufferedWriter bw = null;
    try {
        br = new BufferedReader(
                new InputStreamReader(new FileInputStream(file), "UTF-8"));
        File fileToWrite = new File(file.getParentFile().getAbsolutePath()
                + File.separator + "anonym_"
                + file.getName());
        bw = new BufferedWriter(new FileWriter(fileToWrite));
        String line;
        while ((line = br.readLine()) != null) {
            bw.write(replacements.getSubstitutedText(line));
            bw.newLine();
        }
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        try {
            if (br != null) {
                br.close();
            }
            if (bw != null) {
                bw.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

parseFile()将被执行，但setVisible将不会执行。如果我删除parseFile()，则会执行setVisible。

如何在设置progressBar后显示doSth()？

完整代码：

Anonymous2类：

package main;

import view.MainView;

public class Anonymous2 {

    public static void main(String[] args) {
            new MainView().open();
    }
}

Class MainView：

package view;

import java.io.File;

import org.eclipse.jface.viewers.TableViewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.TableEditor;
import org.eclipse.swt.layout.FormAttachment;
import org.eclipse.swt.layout.FormData;
import org.eclipse.swt.layout.FormLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.List;
import org.eclipse.swt.widgets.ProgressBar;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Table;
import org.eclipse.swt.widgets.TableColumn;
import org.eclipse.swt.widgets.TableItem;

import controller.MainViewController;

public class MainView {

protected Shell shlAnonymous;
private List list;
private Table table;
private TableViewer tableViewer;
private TableEditor editor;
private ProgressBar progressBar;

public Table getTable() {
    return table;
}
public TableViewer getTableViewer() {
    return tableViewer;
}
public Shell getShell() {
    return shlAnonymous;
}
public TableEditor getEditor() {
    return editor;
}
public ProgressBar getProgressBar() {
    return progressBar;
}

/**
 * @wbp.parser.entryPoint
 */
public void open() {
    Display display = Display.getDefault();

    shlAnonymous = new Shell();

    shlAnonymous.setSize(800, 404);
    shlAnonymous.setText("Anonymous");
    shlAnonymous.setLayout(new FormLayout());

    createContents();

    shlAnonymous.open();
    shlAnonymous.layout();

    while (!shlAnonymous.isDisposed()) {
        if (!display.readAndDispatch()) {
            display.sleep();
        }
    }
}

/**
 * Create contents of the window.
 */
protected void createContents() {
    MainViewController controller = new MainViewController(this);

    Label lblHeader = new Label(shlAnonymous, SWT.NONE);
    FormData fd_lblHeader = new FormData();
    fd_lblHeader.top = new FormAttachment(0, 10);
    fd_lblHeader.left = new FormAttachment(0, 10);
    lblHeader.setLayoutData(fd_lblHeader);
    lblHeader.setText("Files to Replace");

    Button btnQuit = new Button(shlAnonymous, SWT.NONE);
    btnQuit.addSelectionListener(controller);
    FormData fd_btnQuit = new FormData();
    fd_btnQuit.left = new FormAttachment(100, -106);
    fd_btnQuit.bottom = new FormAttachment(100, -10);
    fd_btnQuit.right = new FormAttachment(100, -10);
    btnQuit.setLayoutData(fd_btnQuit);
    btnQuit.setText("Quit");
    btnQuit.setData("name", "quit");

    Button btnAnon = new Button(shlAnonymous, SWT.NONE);
    btnAnon.addSelectionListener(controller);
    FormData fd_btnAnon = new FormData();
    fd_btnAnon.right = new FormAttachment(btnQuit, 0, SWT.RIGHT);
    fd_btnAnon.bottom = new FormAttachment(btnQuit, -6);
    fd_btnAnon.left = new FormAttachment(btnQuit, 0, SWT.LEFT);
    btnAnon.setLayoutData(fd_btnAnon);
    btnAnon.setText("Replace");
    btnAnon.setData("name", "anon");

    Button btnAdd = new Button(shlAnonymous, SWT.NONE);
    btnAdd.addSelectionListener(controller);
    FormData fd_btnAdd = new FormData();
    fd_btnAdd.right = new FormAttachment(0, 106);
    fd_btnAdd.bottom = new FormAttachment(100, -10);
    fd_btnAdd.left = new FormAttachment(0, 10);
    btnAdd.setLayoutData(fd_btnAdd);
    btnAdd.setText("Add");
    btnAdd.setData("name", "add");

    Button btnDelete = new Button(shlAnonymous, SWT.NONE);
    btnDelete.addSelectionListener(controller);
    FormData fd_btnDelete = new FormData();
    fd_btnDelete.right = new FormAttachment(btnAdd, 102, SWT.RIGHT);
    fd_btnDelete.bottom = new FormAttachment(100, -10);
    fd_btnDelete.left = new FormAttachment(btnAdd, 6);
    btnDelete.setLayoutData(fd_btnDelete);
    btnDelete.setText("Delete");
    btnDelete.setData("name", "delete");

    list = new List(shlAnonymous, SWT.BORDER | SWT.MULTI);
    list.addKeyListener(controller);
    FormData fd_list = new FormData();
    fd_list.left = new FormAttachment(0, 10);
    fd_list.bottom = new FormAttachment(btnAnon, 0, SWT.BOTTOM);
    fd_list.top = new FormAttachment(lblHeader, 6);
    list.setLayoutData(fd_list);

    table = new Table(shlAnonymous, SWT.BORDER | SWT.FULL_SELECTION);
    table.setLinesVisible(true);
    fd_list.right = new FormAttachment(table, -6);
    FormData fd_table = new FormData();
    fd_table.right = new FormAttachment(btnAnon, -22);
    fd_table.bottom = new FormAttachment(100, -41);
    fd_table.top = new FormAttachment(0, 31);
    fd_table.left = new FormAttachment(0, 336);
    table.setLayoutData(fd_table);
    table.setHeaderVisible(true);

    tableViewer = new TableViewer(table);
    tableViewer.setUseHashlookup(true);

    TableColumn tblclmnTerm = new TableColumn(table, SWT.NONE);
    tblclmnTerm.setWidth(160);
    tblclmnTerm.setText("Term");

    TableItem tableItem = new TableItem(table, SWT.NONE);
    tableItem.setText("");

    TableColumn tblclmnSubstitution = new TableColumn(table, SWT.NONE);
    tblclmnSubstitution.setWidth(156);
    tblclmnSubstitution.setText("Replace With");

    progressBar = new ProgressBar(shlAnonymous, SWT.NONE);
    FormData fd_progressBar = new FormData();
    fd_progressBar.right = new FormAttachment(table, 0, SWT.RIGHT);
    fd_progressBar.bottom = new FormAttachment(btnQuit, 0, SWT.BOTTOM);
    fd_progressBar.left = new FormAttachment(btnDelete, 6);
    progressBar.setLayoutData(fd_progressBar);
    progressBar.setMinimum(0);
    progressBar.setVisible(false);
}

public void addListItem(String item) {
    list.add(item);
}

public void addListItems(String rootFolder, String[] items) {
    for (String item : items) {
        addListItem(rootFolder + File.separator + item);
    }
}

public File[] getFilesToParse() {
    File[] files = new File[list.getItemCount()];
    for (int i = 0; i < list.getItemCount(); i++) {
        files[i] = new File(list.getItem(i));
    }
    return files;
}
}

Class MainViewController：

package controller;

import model.Parser;

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.KeyEvent;
import org.eclipse.swt.events.KeyListener;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.FileDialog;

import view.MainView;

public class MainViewController implements SelectionListener, KeyListener {

private MainView mainView;

public MainViewController(MainView mainView) {
    this.mainView = mainView;
}

@Override
public void widgetDefaultSelected(SelectionEvent arg0) {
    processSelectionEvent(arg0);
}

@Override
public void widgetSelected(SelectionEvent arg0) {
    processSelectionEvent(arg0);
}

private void processSelectionEvent(SelectionEvent e) {
    if (e.getSource() instanceof Button) {
        Button button = (Button)e.getSource();
        if (button.getData("name").equals("quit")) {
        } else if (button.getData("name").equals("anon")) {


            mainView.getProgressBar().setVisible(true);
            Parser parser = new Parser();
            parser.parseFiles(mainView.getFilesToParse());


        } else if (button.getData("name").equals("add")) {
            FileDialog fileDialog = new FileDialog(mainView.getShell(), SWT.MULTI);
            fileDialog.setText("Dateien wählen");
            fileDialog.open();
            mainView.addListItems(fileDialog.getFilterPath(), fileDialog.getFileNames());
        }
    }
}

@Override
public void keyPressed(KeyEvent arg0) {}

@Override
public void keyReleased(KeyEvent arg0) {}


}

Class Parser：

package model;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;

public class Parser {

public boolean parseFile(File file) {
    System.out.println("Parsing File: " + file);
    BufferedReader br = null;
    BufferedWriter bw = null;
    try {
        br = new BufferedReader(
                new InputStreamReader(new FileInputStream(file), "UTF-8"));
        File fileToWrite = new File(file.getParentFile().getAbsolutePath()
                + File.separator + "anonym_"
                + file.getName());
        bw = new BufferedWriter(new FileWriter(fileToWrite));
        String line = br.readLine();
        if (line != null) {
            bw.write(line);
            while ((line = br.readLine()) != null) {
                bw.newLine();
                bw.write(line);
            }
        }
        return true;
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        try {
            if (br != null) {
                br.close();
            }
            if (bw != null) {
                bw.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    return false;
}

public void parseFiles(File[] files) {
    for (File file : files) {
        parseFile(file);
    }
}
}

我已经削减了很多代码，但问题仍然存在。

有问题的行是Parser类中的第40-42行。第40行在第41-42行之后执行。

一些解释： 解析器完成工作后，progressBar变为可见。要查看问题，我建议添加足够多的文件（add-Button），以便解析器可以工作（替换 - 按钮）至少1秒。 progressBar将在一秒钟后显示，并且在单击按钮后应立即可见。

1 个答案:

答案 0 :(得分：0)

您不应该在UI线程中运行解析器。当您的代码解析时，swt没有机会重新绘制Progressbar。因此解析完成后会绘制Progressbar。您应该在一个单独的线程中进行解析，并使用Display.asyncExec（）从此Thread更新Progressbar。有关如何执行此操作的示例，请参阅http://git.eclipse.org/c/platform/eclipse.platform.swt.git/tree/examples/org.eclipse.swt.snippets/src/org/eclipse/swt/snippets/Snippet56.java。

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