java講義19-applet介紹面向?qū)ο蟪绦蛟O(shè)計(jì)

JavaApplet什么是pplJa語言編寫的一段代碼，它可以在瀏覽器環(huán)境中運(yùn)行。它與ppcato不同。aplication是從其中的mai()的ApltTML文件，通過編寫HTMApltApplet oWorld.java源程序：importjava.awt.Graphics;importjava.applet.Applet;publicclass oWorldextendsApplet{Stringhw_text;publicvoidinit()hw_text= o}publicvoidpaint(Graphicsg){g.drawString(hw_text,25,25);}}Applet的運(yùn)為運(yùn)行Applet需要編寫相應(yīng)的HTML文件<APPLETCODE=“ Applet標(biāo) 的文件 width=pixelsheight=pixels 頁面applet之間的通信*/ [vspace=pixels] //>[<paramname=appletAttribute1[<paramname=appletAttribute2 Applet標(biāo)AppletViewer僅支持Applet的類層init(創(chuàng)建Applet時(shí)執(zhí)行,只執(zhí)行一start(當(dāng)瀏覽器從圖標(biāo)恢復(fù)成窗口主頁時(shí)執(zhí)行stop(destroy(用來釋放資源，在stop()之后執(zhí)Applet的生命周

初始(瞬時(shí)

圖標(biāo)化、Browser裝入另一運(yùn)行 停止

消亡Applet的繪paint(進(jìn)行繪圖的具體操作，必須重update(用于更新圖形，先清除背景、前景，再調(diào)用repaint(位置移動(dòng)時(shí)，repaint()方法立即被系統(tǒng)自動(dòng)調(diào)Applet的繪AWTAWTrepaint(update(clearcallpaint(

paint(

Applet的 處圖像處Applet類中與圖像處理有關(guān)的方publicImagegetImage(URLpublicImagegetImage(URLurl,String與Applet位置相關(guān)的方PublicURL獲取Appletcode位置的PublicURL 獲取Web頁位置圖像處importimportpublicclassApplet3extendsImageimg1,img2,publicvoid }publicvoidpaint(Graphics}}聲音處 AudioClip接口中的方voidvoidvoid若 聲音文件，只需從applet對象中獲AudioClip對象即可聲音處Applet類中與聲音有關(guān)的方publicvoidplay(URLpublicvoidplay(URLurl,StringpublicfinalstaticAudioClipnewAudioClip(URLurl)publicAudioClipgetAudioClip(URLpublicAudioClipgetAudioClip(URLurl,Stringname) 聲importimportpublicclassApplet4extendsAudioClippublicvoid}publicvoid}publicvoid}}Applet參<paramname=“value=“值A(chǔ)pplet參importimportpublicclassApplet5extendsAppletimplementsImageStringbooleanintpublicvoid}publicvoidThreadt=new}Applet參publicvoid}publicvoidintGraphicsImageGraphicsg2.drawImage(background,0,0,getWidth(),}catch(Exception}}}使用瀏覽器控制<Appletcode=“Appletname=“名稱”width=300height=100>使用瀏覽器控制importimportpublicclassApplet6extendspublicvoidpaint(Graphics}publicvoidsetBackground(newColor(255,0,}publicvoidsetBackground(newColor(0,255,}publicvoidsetBackground(newColor(0,0,}}使用Applet控制瀏覽AppletContext對publicAppletContext使用Applet控制瀏覽AppletContext類的常用方顯示url指定的Webvoid (URLvoidshow (URLurl,String voidshowStatus(Stringstatus)控制其他AppletContext類的常用方 getApplet(Stringname); 控制其他importimportpublicclassApplet8extends abelpublicvoidlabel=newLabel("你好}publicvoidmoveLabel(intx,intlabel.setLocation(x,}}控制其他importimportimportpublicclassApplet8_ControllerextendsAppletimplementsApplet8publicvoid}publicvoidmouseMoved(MouseEventapplet8.moveLabel(me.getX(),}publicvoidmouseDragged(MouseEvent}同時(shí)是Applet與importjava.awt.*;publicclassAppletAppextendsApplet{publicvoidmain(Stringargs[]){Frameframe=newAppletAppapp=newAppletApp();frame.addWindwoListener(newWindowControl(app));}publicvoidpaint(Graphicsg) o}publicvoid}}classWindowControlextendsWindowAdapter{Appletc;publicWindowControl(Appletc){}publicvoidwindowClosing(WindowEvente){c.dest