Question

我正在使用附近的连接来创建设备之间的连接。建立连接后，将更改活动。现在，如果设备断开连接，则将调用回调，但在旧活动中会收到该回调。现在，我想显示一个AlertDialog，但是该对话框从未显示，因为它显示在旧活动上。如何显示有关新活动的对话框？

我正在使用附近的连接，例如：URL

private Activity mActivity;

public RemoteConnection(Activity activity){
    mActivity = activity;
} 

  // For simplicity I did only include this method
  @Override
  public void onDisconnected(String endpointId) {
    // We've been disconnected from this endpoint. No more data can be
    // sent or received.
    new AlertDialog.Builder(mActivity)
      .setTitle("Disconnection")
      .setMessage("Other device is disconnected")
      .setIcon(android.R.drawable.ic_dialog_alert)
      .show();
  }

对话框应显示在当前活动上

Answer 1

在活动中写一个方法为：

public void showAlert(activity)
{
    new AlertDialog.Builder(activity)
  .setTitle("Disconnection")
  .setMessage("Other device is disconnected")
  .setIcon(android.R.drawable.ic_dialog_alert)
  .show();
}

并更改以下代码：

@Override
 public void onDisconnected(String endpointId) {
// We've been disconnected from this endpoint. No more data can be
// sent or received.
new AlertDialog.Builder(mActivity)
  .setTitle("Disconnection")
  .setMessage("Other device is disconnected")
  .setIcon(android.R.drawable.ic_dialog_alert)
  .show();

}

收件人：

@Override
 public void onDisconnected(String endpointId) {
// We've been disconnected from this endpoint. No more data can be
// sent or received.
if(((YourActivityA)activity) != null)
{
    ((YourActivityA)activity).showAlert(activity);
}
else if(((YourActivityB)activity) != null)
{
    ((YourActivityB)activity).showAlert(activity);
}
}

Answer 2

使用事件总线实现或使用sendBroadcast()发送回调，并让每个Activity在BroadcastReceiver中注册一个onResume()，然后在onPause()中取消注册。 / p>

更改活动后如何获取当前活动

2 个答案: