Java实现的图像查看器完整实例
本文实例讲述了Java实现的图像查看器。分享给大家供大家参考。具体如下：
1.MyCanvas.java：
packagePictureViewer;
importjava.awt.*;
importjava.awt.event.*;
importjava.awt.image.*;
publicclassMyCanvasextendsCanvasimplementsComponentListener{
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);
}
publicvoidcomponentResized(ComponentEvente){
if(bi!=null){
System.out.println("resize!!");
this.zoom();
this.repaint();
}
}
publicvoidcomponentMoved(ComponentEvente){}
publicvoidcomponentShown(ComponentEvente){}
publicvoidcomponentHidden(ComponentEvente){}
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);
}
}
2.MyFilter.java：
packagePictureViewer;
importjava.io.File;
importjava.io.FilenameFilter;
publicclassMyFilterimplementsFilenameFilter{
privateString[]extension;
publicMyFilter(){
extension=newString[]{".jpg",".JPG",".gif",".GIF",".png",".PNG",".jpeg",".JPEG"};
}
publicMyFilter(String[]extension){
this.extension=extension;
}
publicbooleanaccept(Filedir,Stringname){
for(Strings:extension){
if(name.endsWith(s)){
returntrue;
}
}
returnfalse;
}
}
3.PictureViewer.java：
packagePictureViewer;
importjava.awt.*;
importjava.awt.event.*;
importjava.awt.image.*;
importjava.io.*;
importjavax.imageio.*;
publicclassPictureViewerimplementsActionListener{
privateFrameframe;
privateMyCanvasmc;
privateStringfpath;
privateStringfname;
privateFile[]files;
privateintfindex;
privateFileDialogfd_load;
privateMyFilterfilter;
privateButtonprevious;
privateButtonnext;
publicstaticvoidmain(Stringargs[])throwsException{
newPictureViewer().init();
}
publicvoidinit(){
frame=newFrame("PictureViewer");
Panelpb=newPanel();
Buttonselect=newButton("选择图片");
previous=newButton("上一张");
next=newButton("下一张");
select.addActionListener(this);
previous.addActionListener(this);
next.addActionListener(this);
pb.add(select);
pb.add(previous);
pb.add(next);
mc=newMyCanvas();
mc.setBackground(newColor(200,210,230));
mc.addComponentListener(mc);
frame.add(pb,"North");
frame.add(mc,"Center");
frame.setSize(360,360);
frame.setLocation(400,200);
frame.addWindowListener(newWindowAdapter(){
publicvoidwindowClosing(WindowEvente){
System.exit(0);
}
});
frame.setVisible(true);
this.validateButton();
filter=newMyFilter();
fd_load=newFileDialog(frame,"打开文件",FileDialog.LOAD);
fd_load.setFilenameFilter(filter);
}
publicvoidactionPerformed(ActionEvente){
Stringcommand=e.getActionCommand();
if(command.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.setIndex();
}
}elseif(command.equals("上一张")){
findex--;
if(findex<0)
findex=0;
this.display(files[findex]);
}elseif(command.equals("下一张")){
findex++;
if(findex>=files.length)
findex=files.length-1;
this.display(files[findex]);
}
this.validateButton();
}
publicvoiddisplay(Filef){
try{
BufferedImagebi=ImageIO.read(f);
mc.setImage(bi);
frame.setTitle("PictureViewer-["+f.getName()+"]");
}catch(Exceptione){
e.printStackTrace();
}
mc.repaint();
}
publicvoidsetIndex(){
Filecurrent=newFile(fpath+fname);
if(files!=null){
for(inti=0;i<files.length;i++){
if(current.equals(files[i])){
findex=i;
}
}
}
}
publicvoidvalidateButton(){
previous.setEnabled((files!=null)&&(findex>0));
next.setEnabled((files!=null)&&(findex<(files.length-1)));
}
}
希望本文所述对大家的java程序设计有所帮助。