Android:如何将蓝牙连接传递给另一个活动? [英] Android: How to pass a Bluetooth connection to another Activity?

问题描述

我有我的第一个活动，其中建立了 BT 连接.有一个选项会呈现给用户，并且会根据他们的选择加载不同的 Activity.

I have my first Activity in which the BT connection is established. There is an option presented to the user and, based on their selection, a different Activity will load.

问题是，这两个活动都需要一个 BT 连接，我不认为为了建立另一个连接而破坏一个连接有什么意义.

The problem is, both activities need a BT connection and I don't see the point in destroying one connection just to make another.

有没有办法在活动之间传递连接?

Is there a way that I could pass the connection between Activities?

有没有人给我一些例子或者链接?

Does anyone have some example for me or perhaps a link?

我试过class MyApplication extends Application"，但后来我不能使用:

I've tried "class MyApplication extends Application", but then I can't use:

super.onCreate(savedInstanceState);
setContentView(R.layout.blablabla);

这可能是一个非常愚蠢的问题，但我只在 Android +- 2 周内.

This may be a pretty silly question but I've only been at Android +- 2 weeks.

推荐答案

您是否尝试过使用 Application 对象将蓝牙连接存储在一个对象中并使用您的活动来获取它?

Have you tried using the Application object to store the Bluetooth connection in an object and using your Activities to get it?

尝试这样的事情.(注意:我从来没有在 Android 上使用过蓝牙，所以我不知道要使用哪些相关的类.在这种情况下，我将使用 BluetoothDevice，因为它似乎是基于正确的类关于图书馆文档)

Try something like this. (Note: I have never worked with Bluetooth on Android, so I don't know which relevant classes to use. In this case, I'll use BluetoothDevice, since it seems to be the right class based on the library documentation)

public class MyApplication extends Application {
    BluetoothDevice device;
    ...
    public synchronized BluetoothDevice getBtConnection() {
        if (device == null) {
            // construct a BluetoothDevice object and put it into variable device
        }
        return device;
    }
}

这样，您的第一个 Activity 只需执行以下操作:

That way, your first activity just has to do this:

public class FirstActivity extends Activity {
    private BluetoothDevice device;
    ...
    @Override
    protected void onCreate(Bundle b) {
        super(b);
        ...
        device = ((MyApplication) getApplication()).getBtDevice();
        ...
    }
    ...
}

然后，任何时候您的其他活动需要使用该连接，它们只需要调用 getBtDevice()，因为 FirstActivity 已经实例化了它.

And then, any time your other Activities need to use that connection, they just need to call getBtDevice(), because FirstActivity already instantiated it.

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