The action is the string that specifies the generic action to perform such as (such as view or pick). Without a component name, the intent is implicit and the system decides which component should receive the intent based on the other intent information (such as the action, data, and category-described below). You can set the component name with setComponent(), setClass(), setClassName(), or with the Intent constructor. It is the name of component to start like activity, service or broadcast. The component name is considered the difference point between implicit and explicit intent. In order to build an intent you need the following informations: Component name #Android studio intent settype androidIn order to android system determines which app component to start, it uses the informations that carried by an intent object. Further more, you can use this feature by declaring an attribute in the element. By contrast, when you use implicity intent you send request that tells the android system to start the activity that can do this task. Intent filters are a powerful method to launch an activity based not only on an explicit request, but also an implicit one. For example, when you explicitly start Gmail App you tell the system to start Send Email Activity in this app. When match found the android system starts the match activity by calling the oncreate() method of the target activity( Activity B) and passing the intent to it. After that the android system searches through all apps that contain the match intent filter. Then cast this intent in the startActivity() method in Activity A. When you want to implicit start Activity B from Activity A, first you create an intent with intent filter. How the implicit intent starts an activity in android system The following image shows how implicit intent starts activity in android. For Example, when you want to send text from your activity with mail, you must specify the action for this intent (ACTION_SEND). Implicit IntentsĪctually, in this type of Intent, you do not specify the target name, but instead declare a general action to perform, which allows a component from another app to handle it. For example, when you start known activity or service in your app. Moreover you can use this type to start a component in your own app, as you know the class name of the activity or service you want to start. With this type of intent you specify the target app, package or class name. You can deliver a broadcast to other apps by passing an Intent to sendBroadcast() or sendOrderedBroadcast(). For example, turning WIFI on and off, or starting device to charge. Moreover, android system delivers various broadcast for system event. 3- Starting a broadcastĪ Broadcast is a message that any app can recieve. Moreover, If the service is designed with a client-server interface, you can bind to the service from another component by passing an Intent to bindService(). Further more, you can start service that can do one time operation such as downloading a file by passing an Intent to startService() method. 2- Starting ServiceĪ Service is the component that can do operation in the background without user interface. Then, you can get the result in the current activity (start activity) in form of separated Intent object in your activity’s onActivityResult() callback. Moreover if you want to get result from the target activity, you can call startActivityForResult() method. This intent should describe the activity that you want to start and also can carry additional data to this activity. In order to start activity in android you need to pass an intent to the method startActivity(). There are several ways where the intent communicate with app components. The ways that intent communicate with app components. For example, when you want to start activity, send message or share image. An Intent is the way to request an action from another app component in form of messaging object. In this article you will learn all about Intent and Intent Filters in android studio.
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