Java课程设计报告的图片浏览器的

-.z.一.课程设计的任务及要求二.需求分析图形化界面（GUI）编程，编写一个图片浏览器程序可以支持““.GIF”，“.JPEG”,“.jpeg”,“.TGA”,“.JPG”,“.jpg”等格式，单打开图片，可以将同一目录下的图片按缩略图打开按“上一”“下一”按钮可以显示相应图片。运行Applet时，图像不是一气呵成的，因为方法不是吧图像完整的装入存再显示的。于此相反，方法创建一个线程，该线程与Applet的原有线程并发执行，一边装入一边显示，从而产生上了不联需显示的现象。为了提高图像才显示效果，可以采用双缓冲技术：首先把图像装入存，然后再显示在屏幕上。三.设计思路3.1界面设计选择图片按钮：主要用dir函数实现图片的遍历。上一，下一：通过做标轴回调函数实现。由于本软件为单机软件，不需要大量的数据读写和数据交换，实现上、下功能要求只能读取PictureBo*控件当前加载的目录，读取当前路径，创建一维数组。frame=newFrame("PictureViewer");Panelpb=newPanel();Buttonselect=newButton("选择图片");previous=newButton("上一");ne*t=newButton("下一");select.addActionListener(this);previous.addActionListener(this);3.2.图像加载：Applet常用来显示储存在文件中的图像，多数Applet使用的是GIF或JPEG格式的图像文件。需Applet加载图像只需首先定义Image对象，然后使用getImage()方法把图像和文件结合起来即可。image_width=bi.getWidth(this); image_height=bi.getHeight(this); doubleimage_proportion=1.0*image_height/image_width; System.out.println("image:w"+image_width+",h"+image_height+",p1"+image_proportion);if(image_proportion>screen_proportion){ image_height=screen_height; image_width=(int)(image_height/image_proportion); System.out.println("p1>p0w="+image_width); }else{ image_width=screen_width; image_height=(int)(image_width*image_proportion); System.out.println("p0>p1h="+image_height);}四.详细设计4.1.程序设计流程图开始开始图片图片上一*上一*查找盘符查找盘符图片图片下一*查找文件下一*查找文件夹结束查找文件结束查找文件4.2.源程序代码packageC;importjava.io.File;importjava.io.FilenameFilter;publicclassMyFilterimplementsFilenameFilter{privateString[]e*tension;publicMyFilter(){e*tension=newString[]{".jpg",".JPG",".gif",".GIF",".png",".PNG",".jpeg",".JPEG"};}publicMyFilter(String[]e*tension){this.e*tension=e*tension;}publicbooleanaccept(Filedir,Stringname){for(Strings:e*tension){if(name.endsWith(s)){returntrue;}}returnfalse;}}packageC;importjava.awt.*; importjava.awt.event.*; importjava.awt.image.*; publicclassMyCanvase*tendsCanvasimplementsponentListener{ /** * */ privatestaticfinallongserialVersionUID=1L; privateBufferedImagebi; privateImageim; privateintimage_width; privateintimage_height; publicvoidsetImage(BufferedImagebi){ this.bi=bi; this.zoom(); } publicvoidpaint(Graphicsg){ g.drawImage(im,(this.getWidth()-image_width)/2,(this.getHeight()-image_height)/2,this); } publicvoidponentResized(ponentEvente){ if(bi!=null){ System.out.println("resize!!"); this.zoom(); this.repaint(); } } publicvoidponentMoved(ponentEvente){} publicvoidponentShown(ponentEvente){} publicvoidponentHidden(ponentEvente){} publicvoidzoom(){ if(bi==null) return; intscreen_width=this.getWidth(); intscreen_height=this.getHeight(); doublescreen_proportion=1.0*screen_height/screen_width; System.out.println("screen:w"+screen_width+",h"+screen_height+",p0"+screen_proportion); image_width=bi.getWidth(this); image_height=bi.getHeight(this); doubleimage_proportion=1.0*image_height/image_width; System.out.println("image:w"+image_width+",h"+image_height+",p1"+image_proportion); if(image_proportion>screen_proportion){ image_height=screen_height; image_width=(int)(image_height/image_proportion); System.out.println("p1>p0w="+image_width); }else{ image_width=screen_width; image_height=(int)(image_width*image_proportion); System.out.println("p0>p1h="+image_height); } im=bi.getScaledInstance(image_width,image_height,Image.SCALE_SMOOTH); } }packageC;importjava.awt.*;importjava.awt.event.*;importjava.awt.image.*;importjava.io.*;importjava*.imageio.*;publicclassTimplementsActionListener{privateFrameframe;privateMyCanvasmc;privateStringfpath;privateStringfname;privateFile[]files;privateintfinde*;privateFileDialogfd_load;privateMyFilterfilter;privateButtonprevious;privateButtonne*t;publicstaticvoidmain(Stringargs[])throwsE*ception{newT().init();}publicvoidinit(){frame=newFrame("PictureViewer");Panelpb=newPanel();Buttonselect=newButton("选择图片");previous=newButton("上一");ne*t=newButton("下一");select.addActionListener(this);previous.addActionListener(this);ne*t.addActionListener(this);pb.add(select);pb.add(previous);pb.add(ne*t);mc=newMyCanvas();mc.setBackground(newColor(200,210,230));mc.addponentListener(mc);frame.add(pb,"North");frame.add(mc,"Center");frame.setSize(360,360);frame.setLocation(400,200);frame.addWindowListener(newWindowAdapter(){publicvoidwindowClosing(WindowEvente){System.e*it(0);}});frame.setVisible(true);this.validateButton();filter=newMyFilter();fd_load=newFileDialog(frame,"打开文件",FileDialog.LOAD);fd_load.setFilenameFilter(filter);}publicvoidactionPerformed(ActionEvente){Stringmand=e.getActionmand();if(mand.equals("选择图片")){fd_load.setVisible(true);fpath=fd_load.getDirectory();fname=fd_load.getFile();if((fpath!=null)&&(fname!=null)){this.display(newFile(fpath+fname));files=newFile(fpath).listFiles(filter);this.setInde*();}}elseif(mand.equals("上一")){finde*--;if(finde*<0)finde*=0;this.display(files[finde*]);}elseif(mand.equals("下一")){finde*++;if(finde*>=files.length)finde*=files.length-1;this.display(files[finde*]);}this.validateButton();}publicvoiddisplay(Filef){try{BufferedImagebi=ImageIO.read(f);mc.setImage(bi);frame.setTitle("PictureViewer-["+f.getName()+"]");}catch(E*ceptione){e.printStackTrace();}mc.repaint();}publicvoidsetInde*(){Filecurrent=newFile(fpath+fname);if(files!=null){for(inti=0;i<files.length;i++){if(current.equals(files[i])){finde*=i;}}}}publicvoidvalidateButton(){previous.setEnabled((files!=null)&&(finde*>0));ne*t.setEnabled((files!=null)&&(finde*<(files.length-1)));}}五.运行调试与分析讨论5.1.将同一目录下的图片按缩略图打开5.2.单打开图片5.3.按”上一”,”下一”按钮打开图片六.设计体会与小结我通过这次编程实践学习到了Image和Griphics相关的类的使用。首先我通过网上搜集资料和自己看jdkapi对Image、graphics、swing中的类有了实质