在 Android Manifest 中添加两个活动

Question

我的 android 项目中有一个 main.xml，它具有以下控制权

TextBox1 按钮1 文本框2按钮2

文本框3
文本框4 标签1

按钮3

我有两个活动名称 DatePickerDialogAppsActivity 和 JSONSampleAppActivity。

Datepickerdialogappsactivity 具有在 button1 和 button2 点击事件上弹出数据选择器的功能

Jsonsampleactivity 与我的 sql 数据库连接，并在 button3 点击事件上使用标签绑定数据，从 textbox3 和 textbox4 中的用户获取输入

问题：我的 main.xml 文件同时访问 datepickerdialogappsactivity 和 jsonsampleactivity 我应该如何定义活动和清单文件。

这是我的代码，每次只有一个活动运行意味着我在第一个节点上定义的每个活动都可以工作，其次是不工作。例如，在下面的代码中 datepickerdialogappsactivity 有效，而 jsonsampleactivity 不起作用，如果我首先定义 jsonsample 活动，它将起作用，然后第二个将不起作用，请指导

<application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:name=".DatePickerDialogAppsActivity"

            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    <activity
            android:name=".jsonsampleactivity"

            android:label="@string/app_name" >

        </activity>


    </application>

Main.xml 代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
 <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />

    <EditText
        android:id="@+id/editText1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" 
        android:hint="From Date"
        >

        <requestFocus />
    </EditText>


    <EditText
        android:id="@+id/editText2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" 
        android:hint="To Date"
        >

        <requestFocus />
    </EditText>

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
       android:width="150px"

        android:onClick="showDatePickerDialog"
        android:text="From Date" />

      <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"

          android:width="150px"

        android:onClick="showDatePickerDialogg"
        android:text="To Date" />

    <EditText
        android:id="@+id/txtUserName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" 
        android:hint="User Name"
        >

        <requestFocus />
    </EditText>

    <EditText
        android:id="@+id/txtPassword"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" 
        android:hint="Password"
        android:inputType="textPassword"
        />


    <Button
        android:id="@+id/btnLogin"
        android:layout_width="128dp"
        android:layout_height="wrap_content"
        android:text="Button" />

    <TextView
        android:id="@+id/lblStatus"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Status"
        android:textAppearance="?android:attr/textAppearanceLarge" />


</LinearLayout>

日期选择器代码

package com.Android.JSONApp;

import java.util.Calendar;

import android.app.Activity;
import android.app.DatePickerDialog;
import android.app.Dialog;
import android.os.Bundle;
import android.view.View;
import android.widget.DatePicker;
import android.widget.EditText;



public class DatePickerDialogAppsActivity extends Activity {
    /** Called when the activity is first created. */
    static final int DATE_DIALOG_ID=0;
    static final int DATE_DIALOG_IDD=1;
    int yr,mon,day, yrr, monn, dayy;



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



    }


    public void showDatePickerDialog(View v)
    {
         Calendar today=Calendar.getInstance();
         yr=today.get(Calendar.YEAR);
         mon=today.get(Calendar.MONTH);
         day=today.get(Calendar.DAY_OF_MONTH);
        showDialog(DATE_DIALOG_ID);
    }

    public void showDatePickerDialogg(View v)
    {
         Calendar today=Calendar.getInstance();
         yrr=today.get(Calendar.YEAR);
         monn=today.get(Calendar.MONTH);
         dayy=today.get(Calendar.DAY_OF_MONTH);
        showDialog(DATE_DIALOG_IDD);
    }
    protected Dialog onCreateDialog(int id)
    {
        switch (id) {
        case DATE_DIALOG_ID:
            return new DatePickerDialog(this,dateSetListener,yr,mon+1,day);
        case DATE_DIALOG_IDD:
            return new DatePickerDialog(this,dateSetListenerr,yrr,monn+1,dayy);
        }
        return null;
    }
    private DatePickerDialog.OnDateSetListener dateSetListener=new DatePickerDialog.OnDateSetListener() {

        @Override
        public void onDateSet(DatePicker view, int year, int monthOfYear,
                int dayOfMonth) {
            // TODO Auto-generated method stub
            yr=year;
            mon=monthOfYear +1;
            day=dayOfMonth;
            EditText it=(EditText)findViewById(R.id.editText1);

            it.setText(day+" - "+mon+" - "+yr);
        }
    };

private DatePickerDialog.OnDateSetListener dateSetListenerr=new DatePickerDialog.OnDateSetListener() {

        @Override
        public void onDateSet(DatePicker view, int yearr, int monthOfYearr,
                int dayOfMonthh) {
            // TODO Auto-generated method stub
            yrr=yearr;
            monn=monthOfYearr +1;
            dayy=dayOfMonthh;
            EditText itt=(EditText)findViewById(R.id.editText2);

            itt.setText(dayy+" - "+monn+" - "+yrr);
        }
    };
}

json示例代码

package com.Android.JSONApp;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class JSONSampleAppActivity extends Activity implements OnClickListener{
    /** Called when the activity is first created. */

    //Property declaration
    Button btnLogin;
    TextView lblStatus;
    EditText txtUserName,txtPassword;


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

        btnLogin=(Button)findViewById(R.id.btnLogin);
        btnLogin.setOnClickListener(this);

        lblStatus=(TextView)findViewById(R.id.lblStatus);

        txtUserName=(EditText)findViewById(R.id.txtUserName);
        txtPassword=(EditText)findViewById(R.id.txtPassword);
    }

    @Override
    public void onClick(View v) {

        switch(v.getId())
        {
            case R.id.btnLogin:
                String userName=txtUserName.getText().toString();
                String password=txtPassword.getText().toString();
                if(verifyLogin(userName,password))
                {
                    lblStatus.setText("Login Successful");
                }
                else
                {
                    lblStatus.setText("Login Failed");
                }
                break;
        }
    }

    public static String convertStreamToString(InputStream is) 
    {
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        StringBuilder sb = new StringBuilder();

        String line = null;
        try {
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
        } 
        catch (IOException e) {
            e.printStackTrace();
        } 
        finally {
            try {
                is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return sb.toString();
    }

    public static boolean verifyLogin(String UserName,String Password)
    {
        try
        {
            System.out.println("guru");
            DefaultHttpClient httpClient=new DefaultHttpClient();

            //Connect to the server
            HttpGet httpGet=new HttpGet("http://xxx/Service1.svc/checkLogin?name="+UserName+"&pass="+Password);
            //Get the response
            HttpResponse httpResponse = httpClient.execute(httpGet);
            HttpEntity httpEntity = httpResponse.getEntity();
            InputStream stream=httpEntity.getContent();

            //Convert the stream to readable format
            String result= convertStreamToString(stream);

            if(result.charAt(1)=='1')
            {
                return true;
            }
            else
            {
                return false;
            }
        }
        catch(Exception e)
        {
            return false;
        }

    }


}

Answer 1

您可以使用一个 Activity 来完成这两项工作，如下所示：

public class MainActivity extends Activity {
/** Called when the activity is first created. */
static final int DATE_DIALOG_ID=0;
static final int DATE_DIALOG_IDD=1;
int yr,mon,day, yrr, monn, dayy;

Button btnLogin;
TextView lblStatus;
EditText txtUserName,txtPassword;

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


    btnLogin=(Button)findViewById(R.id.btnLogin);
    btnLogin.setOnClickListener(this);

    lblStatus=(TextView)findViewById(R.id.lblStatus);

    txtUserName=(EditText)findViewById(R.id.txtUserName);
    txtPassword=(EditText)findViewById(R.id.txtPassword);
}


public void showDatePickerDialog(View v)
{
     Calendar today=Calendar.getInstance();
     yr=today.get(Calendar.YEAR);
     mon=today.get(Calendar.MONTH);
     day=today.get(Calendar.DAY_OF_MONTH);
    showDialog(DATE_DIALOG_ID);
}

public void showDatePickerDialogg(View v)
{
     Calendar today=Calendar.getInstance();
     yrr=today.get(Calendar.YEAR);
     monn=today.get(Calendar.MONTH);
     dayy=today.get(Calendar.DAY_OF_MONTH);
    showDialog(DATE_DIALOG_IDD);
}
protected Dialog onCreateDialog(int id)
{
    switch (id) {
    case DATE_DIALOG_ID:
        return new DatePickerDialog(this,dateSetListener,yr,mon+1,day);
    case DATE_DIALOG_IDD:
        return new DatePickerDialog(this,dateSetListenerr,yrr,monn+1,dayy);
    }
    return null;
}
private DatePickerDialog.OnDateSetListener dateSetListener=new DatePickerDialog.OnDateSetListener() {

    @Override
    public void onDateSet(DatePicker view, int year, int monthOfYear,
            int dayOfMonth) {
        // TODO Auto-generated method stub
        yr=year;
        mon=monthOfYear +1;
        day=dayOfMonth;
        EditText it=(EditText)findViewById(R.id.editText1);

        it.setText(day+" - "+mon+" - "+yr);
    }
};

private DatePickerDialog.OnDateSetListener dateSetListenerr=new     DatePickerDialog.OnDateSetListener() {

    @Override
    public void onDateSet(DatePicker view, int yearr, int monthOfYearr,
            int dayOfMonthh) {
        // TODO Auto-generated method stub
        yrr=yearr;
        monn=monthOfYearr +1;
        dayy=dayOfMonthh;
        EditText itt=(EditText)findViewById(R.id.editText2);

        itt.setText(dayy+" - "+monn+" - "+yrr);
    }
};

@Override
public void onClick(View v) {

    switch(v.getId())
    {
        case R.id.btnLogin:
            String userName=txtUserName.getText().toString();
            String password=txtPassword.getText().toString();
            if(verifyLogin(userName,password))
            {
                lblStatus.setText("Login Successful");
            }
            else
            {
                lblStatus.setText("Login Failed");
            }
            break;
    }
}

public static String convertStreamToString(InputStream is) 
{
    BufferedReader reader = new BufferedReader(new InputStreamReader(is));
    StringBuilder sb = new StringBuilder();

    String line = null;
    try {
        while ((line = reader.readLine()) != null) {
            sb.append(line + "\n");
        }
    } 
    catch (IOException e) {
        e.printStackTrace();
    } 
    finally {
        try {
            is.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    return sb.toString();
}

public static boolean verifyLogin(String UserName,String Password)
{
    try
    {
        System.out.println("guru");
        DefaultHttpClient httpClient=new DefaultHttpClient();

        //Connect to the server
        HttpGet httpGet=new HttpGet("http://xxx/Service1.svc/checkLogin?name="+UserName+"&pass="+Password);
        //Get the response
        HttpResponse httpResponse = httpClient.execute(httpGet);
        HttpEntity httpEntity = httpResponse.getEntity();
        InputStream stream=httpEntity.getContent();

        //Convert the stream to readable format
        String result= convertStreamToString(stream);

        if(result.charAt(1)=='1')
        {
            return true;
        }
        else
        {
            return false;
        }
    }
    catch(Exception e)
    {
        return false;
    }

}
}

Answer 2

在这两个活动中，使用：

setContentView(R.layout.main);

但是，如果两个活动具有相同的布局，您想要实现什么？

根据经验，您应该始终为不同的活动使用不同的 xml。

Answer 3

如果两个Activities 共享相同的布局，就功能而言是可以的（但至少在设计方面很奇怪，因为Activity 类旨在通过UI 与用户交互）：在Android 中只有一个@987654324 @可以同时显示。因此，您不能同时显示 2 个活动。如果您从另一个Activity 开始，第一个将被暂停。如果您希望这两个活动都显示在启动器中，则它们都应具有以下内容：

<intent-filter>
    <action android:name="android.intent.action.MAIN" />

    <category android:name="android.intent.category.LAUNCHER" />
</intent-filter>

但其中一个也应该注释为默认值：

<category android:name="android.intent.category.DEFAULT"/>