qtjambi - 主要方法之外的QApplication.initialize

Question

我想使用qt jambi來製作截圖。我使用集成的webkit瀏覽器，它像一個魅力。問題是：

我怎麼能初始化

QApplication.initialize（參數）;

以外的主要方法。由於我想在不調用外部程序的情況下從我的Java Web應用程序中截取屏幕截圖，所以我需要在主外部初始化QApplication。

import java.io.BufferedReader; 
import java.io.FileReader; 
import java.io.IOException; 

import com.trolltech.qt.core.QObject; 
import com.trolltech.qt.core.QUrl; 
import com.trolltech.qt.gui.QApplication; 
import com.trolltech.qt.gui.QImage; 
import com.trolltech.qt.gui.QPainter; 
import com.trolltech.qt.webkit.QWebPage; 
import com.trolltech.qt.webkit.QWebView; 

/** 
* 
* @author Marc Giombetti Created on: 16.04.2010 
*/ 
public class ScreenshotWithoutWindow { 
    private QWebView browser; 

    /** 
    * @param args 
    */ 
    public static void main(String[] args) { 
     if (args.length > 2) { 
      String file = args[0]; 
      String baseUrl = args[1]; 
      String writeTo = args[2]; 

      Thumbnailer thumbnail = new Thumbnailer(file, baseUrl, writeTo); 

     } else { 
      System.out.println("Please provide file, baseURL and savetoPath parameters"); 
      System.out 
        .println("For example:java -jar ScreenshotWithoutWindow C:\\test\\test.htm file:///C:/Marc/test/ c:\\screenshot\\screenshot-new.png"); 
     } 
    } 

    public static class Thumbnailer extends QObject { 
     private QWebPage page = new QWebPage(); 
     public Signal0 finished = new Signal0(); 
     private static String file; 
     private static String baseUrl; 
     private static String writeTo; 

     public Thumbnailer(String _file, String _baseUrl, String _writeTo) { 
      file = _file; 
      baseUrl = _baseUrl; 
      writeTo = _writeTo; 

      initialize(); 

     } 

     private void initialize(){ 
      QApplication.initialize(null); 
      page.loadFinished.connect(this, "render(Boolean)"); 
      try { 
       page.mainFrame().setHtml(readFileAsString(file), new QUrl(baseUrl)); 
      } catch (IOException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
      } 
      finished.connect(QApplication.instance(), "quit()"); 
      QApplication.exec(); 
     } 

     void render(Boolean b) { 
      page.setViewportSize(page.mainFrame().contentsSize()); 
      QImage image = new QImage(page.viewportSize(), QImage.Format.Format_ARGB32); 
      QPainter painter = new QPainter(image); 

      page.mainFrame().render(painter); 
      painter.end(); 
      image.save(writeTo); 
      System.out.println("Saved screenshot as "+writeTo); 
      finished.emit(); 

     } 

     private static String readFileAsString(String filePath) throws java.io.IOException { 
      StringBuffer fileData = new StringBuffer(1000); 
      BufferedReader reader = new BufferedReader(new FileReader(filePath)); 
      char[] buf = new char[1024]; 
      int numRead = 0; 
      while ((numRead = reader.read(buf)) != -1) { 
       String readData = String.valueOf(buf, 0, numRead); 
       fileData.append(readData); 
       buf = new char[1024]; 
      } 
      reader.close(); 
      return fileData.toString(); 
     } 
    } 

} 

這不起作用，應用程序崩潰，一個致命的錯誤：

# A fatal error has been detected by the Java Runtime Environment: 
# 
# EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x670ddc30, pid=4588, tid=2776 
# 
# JRE version: 6.0_17-b04 
# Java VM: Java HotSpot(TM) Client VM (14.3-b01 mixed mode windows-x86) 
# Problematic frame: 
# C [QtCore4.dll+0xddc30] 

有沒有人有一個想法如何初始化的主要方法之外的QApplication。

Answer 1

嘗試調用初始化爲new String[0]而不是null。

Answer 2

只需使用這樣的： 其中，形式爲：

public class Form{ 
 
    Ui_Form ui; 
 
    QWidget wid; 
 
    ... 
 
}

String[] a = {null, "a", "a"}; 
QApplication.initialize(a); 
Form f = new Form(); 
f.wid.show(); 
QApplication.exec();