One of the four Android components broadcast recipients

One of the four components

Broadcast recipient Broadcasetrecevice

The mechanism of information transfer in Android:

Broadcast: One-way, mass

To create a feature:

1. Declare an inheritance broadcasetrecevice

2. Declare in the manifest file

Package name. Class Name

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To receive a broadcast: To register a broadcast recipient's filter:

There are two forms of registered broadcast recipients:

The first: Register directly in the manifest file:

Example: Receiving SMS

1. Permission issues to receive text messages

<uses-permission android:name= "Android.permission.RECEIVE_SMS"/>

2. Filter conditions for SMS

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3. Modify the contents of the Onrecevice ().

Once the broadcast is received, the current method is triggered

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Note: The method of registering the filter condition of the broadcast receiver in the manifest file has the following characteristics:

Even if the broadcast recipient's app is not executing, as long as the broadcast filter condition is always received and the Onrecevice () method is triggered

The second method of broadcasting registration:

Code:

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2. Logout

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Note: A broadcast recipient registered in the code can receive it only when the interface is present.

If the interface does not exist, the broadcast will not receive

The difference between manifest file registration and code registration

1. Register the filter in the manifest file: Even if the process does not exist, it can be received as long as the filter matches the broadcast.

2. In the Code Registration filter: The interface exists broadcast to receive. Use is more flexible.

The embodiment of code registration flexibility:

Internal class inheritance can be declared in activity Broadcastreceiver

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Benefits of declaring as internal classes:

When we register our declared broadcast receiver object in this interface, when we receive the broadcast trigger OnReceive () method, in this method we can directly modify the member variable of the activity and call its method.

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One of the four Android components broadcast recipients