Question

我正在尝试开发网络应用程序，在网络断开时显示对话框。我做了一切，但对话框内的文字没有居中。

    package com.example.ayyappaboddupalli.networkchecker;

import android.app.Application;
import android.content.Context;
import android.content.DialogInterface;
import android.content.IntentFilter;
import android.net.ConnectivityManager;
import android.support.v7.app.AlertDialog;
import android.view.LayoutInflater;
import android.view.View;

/**
 * Created by ayyappaboddupalli on 10/23/2017.
 */

public class ApplicationClass extends Application implements android.app.AlertDialog.OnDismissListener {
    private static ApplicationClass mInstance;
    private NetworkObserver networkObserver;
    private NetworkDetector detector;
    private AlertDialog.Builder ad = null;
    private AlertDialog alertDialog;

    public AlertDialog getAlertDialog() {
        return alertDialog;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        networkObserver = new NetworkObserver();

    }

    public static ApplicationClass getmInstance() {

        if (mInstance == null) {
            synchronized (Object.class) {
                mInstance = mInstance == null ? new ApplicationClass() : mInstance;
            }
        }
        return mInstance;

    }

    public NetworkObserver getNetworkObserver() {
        if (networkObserver == null) {
            networkObserver = new NetworkObserver();
            return networkObserver;
        } else {
            return networkObserver;
        }
    }

    public void registerReceiver(Context context) {
        detector = new NetworkDetector();
        context.registerReceiver(detector, new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION));

    }

    public void unRegisterReciver(Context context) {
        try {
            unregisterReceiver(detector);

        } catch (Exception f) {

        }
    }

    public void showDialog(Context context) {
        if(alertDialog!=null)
        {
            alertDialog.dismiss();
        }
            ad = new AlertDialog.Builder(context);
            LayoutInflater layoutInflater = (LayoutInflater) context.getSystemService(LAYOUT_INFLATER_SERVICE);
            View view = layoutInflater.inflate(R.layout.weak_net_dialog, null);
            ad.setView(view);
            alertDialog = ad.create();
            alertDialog.show();
            alertDialog.setCancelable(false);

    }

    @Override
    public void onDismiss(DialogInterface dialog) {
        alertDialog=null;
    }
}

public class NetworkDetector extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {

    boolean isNetOn=isnetworkOnline(context);
    ApplicationClass.getmInstance().getNetworkObserver().setValue(isNetOn);

}

public boolean isnetworkOnline(Context context)
{
    try {
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo netInfo = cm.getActiveNetworkInfo();
        //should check null because in airplane mode it will be null
        return (netInfo != null && netInfo.isConnected());
    } catch (NullPointerException e) {
        e.printStackTrace();
        return false;
    }

}

}

public class NetworkObserver extends Observable {
    private boolean netWorkOff=false;

    public boolean isNetWorkOff() {
        return netWorkOff;
    }

    public void setValue(boolean netWorkOff) {
        this.netWorkOff = netWorkOff;
        setChanged();
        notifyObservers();
    }
}

@Override
    public void update(Observable o, Object arg) {

        if(ApplicationClass.getmInstance().getNetworkObserver().isNetWorkOff()) {
            Toast.makeText(getApplicationContext(),"Network is online",Toast.LENGTH_LONG).show();
            if(ApplicationClass.getmInstance().getAlertDialog()!=null&&ApplicationClass.getmInstance().getAlertDialog().isShowing())
            ApplicationClass.getmInstance().getAlertDialog().dismiss();

        }
        else
        {

            ApplicationClass.getmInstance().showDialog(this);

//            Toast.makeText(getApplicationContext(),"Network is offline",Toast.LENGTH_LONG).show();

        }
    }

Answer 1

在ur xml文件中使用以下行：

android:center_vertical = true
android:center_horizontal=true

如果您使用relativeLayout，它将起作用还将宽度设置为对话的match_parent和editText

Answer 2

试试这个：

${postBody}

将文本置于全屏对话框中

2 个答案: