如何在RecycerView.Adapter中从ViewHolder调用MainActivity方法？

Question

在GitHub的一个简单应用程序项目中，我只有两个自定义Java文件：

1. MainActivity.java包含与蓝牙和UI相关的源代码
2. DeviceListAdapter.java包含适配器和查看器，用于在RecycerView
中显示蓝牙设备

MainActivity.java包含一个方法，当用户点击RecycerView中的蓝牙设备时，该方法将被调用：

public void confirmConnection(String address) {
    final BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);

    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setMessage("Do you want to pair to " + device + "?");
    builder.setPositiveButton(R.string.button_ok, 
      new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int id) {
            device.createBond();
        }
    });
    builder.setNegativeButton(R.string.button_cancel, null);
    builder.show();
}

public class DeviceListAdapter extends
  RecyclerView.Adapter<DeviceListAdapter.ViewHolder> {

  private ArrayList<BluetoothDevice> mDevices = new ArrayList<BluetoothDevice>();

  protected static class ViewHolder
        extends RecyclerView.ViewHolder
        implements View.OnClickListener {

    private TextView deviceAddress;

    public ViewHolder(View v) {
        super(v);
        v.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        String address = deviceAddress.getText().toString();

        Toast.makeText(v.getContext(),
                "How to call MainActivity.confirmConnection(address)?",
                Toast.LENGTH_SHORT).show();
    }
  }

我的问题：

如何从viewholdersonclick方法调用confirmConnection(address)方法？

我一直在两个Java文件之间移动viewholder类声明，并尝试将其放入自己的文件中--但找不到正确的方法。

    @Override
    public void onClick(View v) {
        String address = deviceAddress.getText().toString();

        try {
            ((MainActivity) v.getContext()).confirmConnection(address);
        } catch (Exception e) {
            // ignore
        }
    }

Answer 1

为了保持类的解耦，我建议在适配器上定义一个接口，类似于：

public interface OnBluetoothDeviceClickedListener {
    void onBluetoothDeviceClicked(String deviceAddress);
}

然后在适配器中为此添加一个设置器：

private OnBluetoothDeviceClickedListener mBluetoothClickListener;

public void setOnBluetoothDeviceClickedListener(OnBluetoothDeviceClickedListener l) {
    mBluetoothClickListener = l;
}

然后在内部，在查看器的onclick()中：

if (mBluetoothClickListener != null) {
    final String addresss = deviceAddress.getText().toString();
    mBluetoothClickListener.onBluetoothDeviceClicked(address);
}

mDeviceListAdapter.setOnBluetoothDeviceClickedListener(new OnBluetoothDeviceClickedListener() {
    @Override
    public void onBluetoothDeviceClicked(String deviceAddress) {
        confirmConnection(deviceAddress);
    }
});