Question

我对这个机器人的事情很新鲜，所以我仍然对某些概念感到困惑。我想要做的是，当我在我的启动画面时，当用户没有连接到互联网时显示AlertDialog。我试图在很多方面做到这一点，但我永远不会持有线程，所以我总是得到一个例外，因为活动在关闭对话框之前关闭。我试过用Handler做这个但没有成功......部分代码在这里：

public class Splash extends Activity {

 public void openDialog() {
     AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
            this);

        // set title
        alertDialogBuilder.setTitle(R.string.app_name);

        // set dialog message
        alertDialogBuilder
            .setMessage(R.string.dialogo_net)
            .setCancelable(false)
            .setPositiveButton("Sair",new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog,int id) {
                    Splash.this.finish();
                }
              })
            .setNegativeButton("Definições",new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog,int id) {
                    Intent intent = new Intent(Settings.ACTION_SETTINGS);
                    intent.addCategory(Intent.CATEGORY_LAUNCHER);           
                    startActivity(intent);
                }
            });

            AlertDialog alertDialog = alertDialogBuilder.create();

            alertDialog.show();
        }

 Handler mHandler = new Handler()
 {
     public void handleMessage(Message msg)
     {
        openDialog();//Display Alert
     }
 };

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);     
    setContentView(R.layout.splash);


    Thread logoTimer = new Thread() {
        public void run(){
            try{
                int logoTimer = 0;
                while(logoTimer < 2000){
                    sleep(100);
                    logoTimer = logoTimer +100;
                };
                ConnectivityManager cm =
                     (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
                 NetworkInfo netInfo = cm.getActiveNetworkInfo();
           if (netInfo == null || !netInfo.isConnectedOrConnecting()) {
               //opens the dialog in this case
            mHandler.sendEmptyMessage(0);
              } else {
                //goes to main activity
                startActivity(new Intent("pt.aeist.mobile.START")); }
            } 

            catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

            finally{
                finish();
            }
        }
    };

    logoTimer.start();

}

Answer 1

Thread logoTimer = new Thread() 
 {
    public void run(){
        try{
             sleep(2000);
             ConnectivityManager cm =
                 (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
             NetworkInfo netInfo = cm.getActiveNetworkInfo();

             if (netInfo == null || !netInfo.isConnectedOrConnecting()) 
            {               
                 mHandler.sendEmptyMessage(0);
            } else 
            {
            startActivity(new Intent("pt.aeist.mobile.START")); }
            finish();
            } 
        }catch(Exception e) 
        {
            e.printStackTrace();
        }      
    }
};
logoTimer.start();

Answer 2

//分别处理finish（）。

.setNegativeButton("Definições",new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog,int id) {
                Intent intent = new Intent(Settings.ACTION_SETTINGS);
                intent.addCategory(Intent.CATEGORY_LAUNCHER);           
                startActivity(intent);
                finish();
            }
        });

Answer 3

从所有地方删除finish（）。检查一下。

您必须确定要放置finish（）的情况;

在持有线程的同时创建AlertDialog

3 个答案: