ProgressBar进度条

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1、ProgressBar进度条extendsViewjava.lang.Object↳android.view.View↳android.widget.ProgressBarKnownDirectSubclassesAbsSeekBar,ContentLoadingProgressBarKnownIndirectSubclassesAppCompatRatingBar,RatingBar,SeekBarClassOverviewVisualindicatorofprogressinsomeoperation.Displaysa

2、bartotheuserrepresentinghowfartheoperationhasprogressed;theapplicationcanchangetheamountofprogress(modifyingthelengthofthebar)asitmovesforward.Thereisalsoasecondaryprogressdisplayableonaprogressbarwhichisusefulfordisplayingintermediateprogress,suchasthebufferleveld

3、uringastreamingplaybackprogressbar.Aprogressbarcanalsobemadeindeterminate.Inindeterminatemode,theprogressbarshowsacyclicanimationwithoutanindicationofprogress.Thismodeisusedbyapplicationswhenthelengthofthetaskisunknown.Theindeterminateprogressbarcanbeeitheraspinnin

4、gwheelorahorizontalbar.Thefollowingcodeexampleshowshowaprogressbarcanbeusedfromaworkerthreadtoupdatetheuserinterfacetonotifytheuserofprogress:publicclassMyActivityextendsActivity{privatestaticfinalintPROGRESS=0x1;privateProgressBarmProgress;privateintmProgressStatu

5、s=0;privateHandlermHandler=newHandler();protectedvoidonCreate(Bundleicicle){super.onCreate(icicle);setContentView(R.layout.progressbar_activity);mProgress=(ProgressBar)findViewById(R.id.progress_bar);//StartlengthyoperationinabackgroundthreadnewThread(newRunnable()

6、{publicvoidrun(){while(mProgressStatus<100){mProgressStatus=doWork();//UpdatetheprogressbarmHandler.post(newRunnable(){publicvoidrun(){mProgress.setProgress(mProgressStatus);}});}}}).start();}}Toaddaprogressbartoalayoutfile,youcanusetheelement.Bydefaul

7、t,theprogressbarisaspinningwheel(anindeterminateindicator).Tochangetoahorizontalprogressbar,applytheWidget.ProgressBar.Horizontalstyle,likeso:Ifyouwillusetheprogressbartoshowrealprogress,youmustus

8、ethehorizontalbar.YoucanthenincrementtheprogresswithincrementProgressBy()orsetProgress().Bydefault,theprogressbarisfullwhenitreaches100.Ifnecessa