Pehea e aʻo ai i ka polokalamu polokalamu Android

Inā makemakeʻoe e aʻo i ka papahana pūnaewele Android, ʻaʻole ʻoe hoʻokahi. I ka 'oiaʻiʻo, He mea maʻalahi ke hoʻomaka! Hoʻomaka me Android Studio, ʻO ka Hui Kūʻai Kūʻai Google. Ponoʻoe e pono i ka pahu hanaʻoihana Java. A laila, Hiki iāʻoe ke hoʻomaka e kākau i kāu palapala mua. I ka hopena, e neʻeʻoe i nā mea komo, Iava, Hoʻihoʻi ʻana i ke ola o ka hana, a oi aku!

Huki-a-drop

ʻO Drag-a-Drop merroid App Pūnaewele he papahana maʻalahi a me ka hana ikaika e hiki ke kōkua iāʻoe e kūkulu i nā noi pili nui. Hiki i ke kāʻei a me ka drot mechaninism e hoʻoneʻe iāʻoe e neʻe i nā mea a puni ka app me kaʻole e pili ana i ke koena o ka noi. Hoʻounaʻia nā hanana i nā mea hoʻolohe ma o kahi hanana Android. Aia ka hanana Drag e pili ana i kaʻike e pili ana i ke kūlana o ka mea a hiki ke hoʻokomo i kaʻikepili e like me ka x-y hoʻonohonoho. Loaʻa i ka mea hoʻolohe ke hoʻolohe i kaʻike a kāhea i keʻano o ke ala() a iʻole gyy() E kiʻi i ke kūlana o kēia manawa. Inā ua pau ka hana o ka Drag, Hoʻi hou ka mea hoʻolohe i kahi booole maoli a iʻole wahaheʻe.

Loaʻa iā Drag-and-drop a Android App Programming me ka eclipse 4.4 (Luna) A me Java 1.7. E hoʻokō i ka drag-a-drop, Ponoʻoe e hoʻohui i kahi mea i loko o kāu hana. A laila, E hana i kahi papa inoa inoa e hōʻike ai i ke kiʻi e hōʻikeʻia ai i ka wā o ka hana drag.

Hoʻokomoʻiaʻo Drag-a me Drop a Android App Hoʻolālā e hoʻohana ana i nā papa hana Frag e loaʻa ana a me nā mea hoʻolohe. E hoʻomaka nā hanana Drag me kahi mea hoʻohana mea hoʻohana. A laila, Hāʻawi ka app i kahi hoʻomaka() kahea hou. Inā hoʻoloheʻo ka mea hoʻolohe, ʻAʻole e kāhea ka'ōnaehana i keʻano kelepona. ʻO ka papa hana e like me ka Ontouchevent.

Hiki iāʻoe ke hoʻololi i keʻano o kahi hanana o kahi e kau ai ma o ka laweʻana i nā ala ma waena. This method returns information regarding the size and touch point of the drag event. You can also modify the drag-and-drop gesture by overriding the onDrawShadow method.

Drag-and-drop Android app programming is a simple and flexible technique that lets you build high-quality mobile applications. With drag-and-drop, you can also trigger system events when users perform drag and drop actions.

Manao

Intents are used to communicate between different components in an Android app. An Android application can support both explicit and implicit intents, which are used to control the flow of data from one application to another. An example of this would be a browser window that redirects a user to another application when they open it.

Intents can be a single number or a string, a hoʻohanaʻia e hoʻokaʻawale i nā hana'ē aʻe i loko o kahi app. Ma kahi o ka hoʻokaʻawaleʻana i nā mea'ē aʻe o kahi app, Hiki ke hoʻohanaʻia nā manaʻo e neʻe i nā hana i loko o kahi app. ʻO ke kī ke hoʻohana pono iā lākou. Ponoʻoe e pale i ka serializable a iʻole nāʻikepili i ka wā e hana ana me nā mea makemake.

ʻo kahi laʻana, Hiki iāʻoe ke hoʻohana i kahi kaula hoʻokahi e hōʻike ai i kaʻikepili SOX i kahi mea hoʻohana. A laila, hiki iā lākou ke kaomi ma luna o ka mea hoʻolohe eʻike i nā kiko'ī kālā o ke kumukūʻai. E hōʻikeʻia ka app ma kēia mau kiko'ī i kahi papa inoa. Hiki ke hanaʻia paha ka app ma o kaʻaeʻana i nā mea hoʻohana e koho i ke kumukūʻai i makemakeʻia. E hōʻike ia i kahi papa inoa o nā hale kūʻai e pili ana i ko lākou mau koho koho, komo me nā kūʻai kūʻai a kūʻai aku i nā kauoha.

ʻO nā polokalamu Android pinepine pinepine i kekahi mau kiʻi. I kekahi manawa, Pono nā mea hoʻohana e hoʻololi i waena o nā hana no nā kumu likeʻole. To accomplish this, they use the Intent mechanismu. Intents are used to connect activities within the same app, as well as between apps. To switch between apps, you should create a new intent object and use a suitable Android method.

Intents allow Android apps to provide functionality similar to the web. No ka hana ʻana i kēia, Android apps can implement an intent filter for web links. This means that links that point to web sites will open the Android app instead of a web page. Kahi mea hou aʻe, Android 12 introduced generic web intents, which are used to open the user’s default browser app.

Hoʻihoʻi ʻana i ke ola o ka hana

When you write code in Android apps, you might often come across Activity Lifecycle Callbacks. These callbacks let you know when your app should be closed, restarted, or reverted to the previous state. Pōmaikaʻi, Hiki ke hoʻohanaʻia kēia mau kelepona i nā hanaʻelua a me nā cragments.

ʻEkolu mauʻano hana o nā hana ola ola. Ka mea mua, OBSHTART(), i konoʻia i kēlā me kēia hana i kahi hana mua ma ka pale. Ka lua, onResume(), ua kapaʻia ke hoʻiʻana o kahi hana mai ka hoʻokuʻuʻiaʻana. ʻO kēia kahi kelepona koʻikoʻi no kēlā me kēia polokalamu Android e like me ka hiki ke pale i kāu app mai ka holo lōʻihi.

Ponoʻoe e hoʻomaopopo i ka Android API e hana i kēia mau kelepona. ʻO nā alaʻo Onsntart a me nāʻano onstops i kapaʻia he mau manawa e ka'ōnaehana. ʻO kēia ke kumu e kāhea ai kāu app. E hoʻoliloʻia kēia hana i kāu hana a hunaʻia. Hiki iāʻoe ke haʻi i ka wā i lukuʻia ai ka hana e ka nānāʻana i nā leka logcat.

The onCreate and onDestroy callbacks are triggered by the OS as a result of user interaction. Developers can also override the callbacks. Eia naʻe, when overriding the callbacks, developers should always call the super class method. Failure to do so can result in the app running in a weird state or even crash.

Activity lifecycle callbacks help you understand when your application should enter a paused or stopped state. You should not execute intensive computations during this time, as it can delay the transition to the next state and end the user’s experience.

Logging

Logging Android applications can be a useful tool for developers. Android uses a centralized system for storing log messages, which can be filtered by category or priority. Hiki iāʻoe ke hana i nā memo ma o nā'ōlelo kākau kākauʻana e pili ana i kāu hana a kāu app. He nui nā ala e hoʻopaʻa ai a nānā i nā'ōlelo loiloi.

ʻO kekahi o nā ala maʻalahi e hoʻopaʻaʻia ma ka hoʻohanaʻana i ka papa papa hana i kūkuluʻia. Uaʻae nāʻano hana iʻelua aʻekolu paha mau hoʻopaʻapaʻa. ʻO ka hapa nui o nā leka uila i loaʻa i nā hoʻopaʻapaʻaʻelua. Pono nā hoʻopaʻapaʻa e pili ana i keʻano kaula. ʻO kēiaʻano o ka hoʻopiliʻana e kaupalena ana, Akā he mea maikaʻi ia no nā kumu he nui.

Ua lilo i ka hana a me nā polokalamu a me nā hana hana i kahi hana papahana maʻamau no nā mea hoʻomohala. Laulaha, Pono e hoʻopaʻaʻia kahi polokalamu Android i nā hanana ola i nā manawa a lākou e hele ai. Inā pono ke noi e hana i kahi pilikia, Pono e hoʻopaʻa i kaʻike e kōkua i nā mea hoʻomohala i ka palapala noi. Hiki iāʻoe ke hoʻopaʻa aku i kaʻikepili Debug e hoʻohana ana i ka Log.D() ʻano hana. Hiki i ke ala hope ke hoʻopaʻa pū i nā waiwai hoʻololi a me nā leka paʻi.

ʻOiai ke kōkua nui nei ka hoʻopaʻapaʻaʻana i ka hihia o nā hewa, Hiki i ka uku-ke hōʻemi i ka hana. ʻO ka hoʻomaʻamaʻa maikaʻi loaʻo ia ka hoʻohanaʻana i ka debug loging wale nō no ka hoʻomohalaʻana, A e wehe i ka loulou o ka verbose e hoʻopili ana ma mua o ka hoʻolahaʻana i kāu noi. E like me kahi mea hoʻomohala, Ponoʻoe e nānā mau i ka hoʻopiliʻana i ka hanaʻana ma mua o ka hoʻolahaʻana iā ia. Hele maiʻo Android Sdk me kahi papa hana paʻa. Ua kākauʻo ia i kaʻikepili o ka noi i kahi loiloi i kapaʻiaʻo Logcat. Eia naʻe, ʻO kēiaʻano hana i kekahi mau pilikia hana, no laila e hoʻohanaʻia ana i ka wā e pono ai.

Hiki iāʻoe ke nānā i ka'ōnaehana'ōnaehana ma Android. Aia kēia mau lāʻau i nāʻike i nā mea āpau mai nā hanana maʻamau i nā hanana a me nā lāʻau hōʻai'ē. Hiki iāʻoe ke kānana i ka hoʻopiliʻana o ka loiloi ma ka helu noi noi me ke kōkua o kahi hāmeʻa e like me Android studio.