[Hc Lp trnh Android] Bi 30: Internet ResourceMt trong nhng yu t quan trng gp phn s thnh cng ca in thoi thng minh ngy nay chnh l nh vo s tn ti ca Internet. Khng t nhin m Google t mt nh qun l dch v Internet li chuyn sang mng pht trin h iu hnh v cui cng h thnh cng vi Android khi tt c dch v ca Google u n tn tay ngi dng nh Youtube, Gmail, Google+Trong tun ny ti s hng dn cc bn cch kt ni n Internet v ly v d liu dng hnh nh v hin th n. Tt nhin l cc bn vn c th thc hin tng t i vi d liu khc.To Project, m tp tin activity_main.xml chnh sa nh sau:

layout trn ta c mt Button bt u ly d liu, mt Textview hin tn nh v mt ImageView dng hin th nh. Vo MainActivity.java ln lt khai bo cc i tng trn.

Bin url s dng cha a ch nh, cc bn c dng a ch khc nu mun.Khai bo phng thc kt ni n Internet v chuyn kt ni t InputStream thnh mt hnh nh dng Bitmap.

T phin bn Android 4.0 tr ln chng ta khng c php gi cc phng thc thc hin kt ni n Internet trn tin trnh chnh, nn ti s s dng mt tin trnh ngm c h tr c gi l AsyncTask.AsyncTask c phn ra hai nhim v chnh l thc hin cc phin lm vic trn tin trnh ph (phng thc doInBackground) v tr d liu ln tin trnh chnh khi thc hin xong (phng thc onPostExcute).

Cng vic cn li kh n gin, cc bn vo hm onCreate tin hnh tham chiu cc i tng trong xml v thc hin gi AsynTask khi ngi dng nhn nt.

Trc khi build ng dng, cc bn cn lm thao tc kh quan trng l xin quyn kt ni Internet trong tp tin AndroidManifest.xml v chng ta cn kt ni Internet m!

Hng dnLp trnh Android. Ti m ngun ng dng ti:https://www.dropbox.com/s/ys8cz123dm3wnqy/DemoInternetResource.zip