Question

 package studio_codec.reportingsystem;

 import android.app.Activity;
 import android.content.Context;
 import android.net.ConnectivityManager;
 import android.net.NetworkInfo;
 import android.support.v7.app.ActionBarActivity;

 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.Toast;


 import javax.xml.datatype.Duration;


public class MainActivity extends Activity {

public EditText username = (EditText) findViewById(R.id.username);
public EditText password = (EditText) findViewById(R.id.password);
public String Username = username.getText().toString();
public String Password = password.getText().toString();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


}

protected void onStart() {

    if (!internet_check()) {

        Context context = getApplication();
        int duration = Toast.LENGTH_SHORT;
        CharSequence Error_connection_message = "Please Connect with Internet.Turn on Mobile Data Service";
        Toast Error_Connection = Toast.makeText(context, Error_connection_message, duration);
        Error_Connection.show();;
    }
}


protected void onResume() {

    final Button button = (Button) findViewById(R.id.button);
    button.setOnClickListener(new View.OnClickListener() {
        public void onClick(View button) {

            if (Username == null && (Password.equals(""))) {
                Context context = getApplicationContext();
                CharSequence text = "Please Check your Login Credentials! ";
                int duration = Toast.LENGTH_SHORT;
                Toast Error_credentials = Toast.makeText(context, text, duration);
                Error_credentials.show();


            }

            else{

                // here ..use a function to parse json data and connect to server
            }

        }
    });


}

public boolean internet_check() {
    ConnectivityManager connMgr = (ConnectivityManager)
            getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
    if (networkInfo != null && networkInfo.isConnected()) {

        return true;
    } else {
        return false;
    }
   }
   }

我刚刚阅读了Android Activity Life Cycle，我想知道我编写的代码将按照我的计划运行。我需要代码在用户点击我的应用程序时显示XML文件，一旦在onStart方法中我需要知道设备是否连接到网络，当我需要onResume时，如果用户点击按钮，我需要检查字段是否为空。这里我只有两个文本字段。一个用于用户名，另一个用于密码。谢谢。

Android活动 - 使用onResume方法的客户端到服务器连接

0 个答案: