需要帮助制作Android应用程序

I am learning android development. But I am stucked that ui element don't show in my app's second activity. When loaded.

我正在学习android开发。但我被困在ui元素没有显示在我的应用程序的第二个活动中。加载时

I am using AIDE in my android mobile.

我在Android手机中使用AIDE。

Please take a look at the codes I used up.

请看看我用过的代码。

Main.XML

<?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:gravity="center"
    android:orientation="vertical" >

    <TextView 
        android:textSize="30dp"
        android:gravity="center"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="MSQ CORP" 
        />

    <DigitalClock
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />

    <Button 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/newpage"
        android:text="New Page"
        />
</LinearLayout>

MainActivity.java

package com.mycompany.msqcorp;

import android.app.*;
import android.os.*;
import android.view.*;
import android.widget.*;
import android.content.*;
import android.view.View. *;
import android.widget.Button.*;
import android.content.Intent. *;

public class MainActivity extends Activity
{
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Button a = (Button) findViewById(R.id.newpage);
        a.setOnClickListener(new View.OnClickListener(){

            public void onClick(View v) {

                Intent intent = new Intent(MainActivity.this, secondActivity.class);
                startActivity(intent);
            }
        });
    }
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.mycompany.msqcorp"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk 
        android:minSdkVersion="8" 
        android:targetSdkVersion="21" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:label="@string/app_name"
            android:name=".MainActivity" >
            <intent-filter >
                <action android:name="android.intent.action.MAIN" />

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

        <activity
            android:name="secondActivity"
            android:label="New Page"
    />
    </application>

</manifest>

second.xml

<?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:gravity="center"
    android:orientation="vertical" >

    <TextView 
        android:textSize="10dp"
        android:gravity="center"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Registeration Form" 
        android:padding="10dp"
        android:id="@+id/text1"
    />

    <TextView 
        android:textSize="10dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Full Name : "
        android:id="@+id/text2"
    />

    <EditText
        android:textSize="5dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Enter Your Full Name" 
        android:id="@+id/text3"
    />


</LinearLayout>

SecondActivity.java

package com.mycompany.msqcorp;
import android.system.*;
import android.app. *;
import android.os.*;
import android.view.View. *;
import android.content. *;
import android.test.*;
import android.widget.*;

public class secondActivity extends Activity
{

    @Override
    public void onCreate(Bundle savedInstanceState, PersistableBundle persistentState)
    {
        // TODO: Implement this method
        super.onCreate(savedInstanceState);
        setContentView(R.layout.second);


    }

}

When I run the app, it shows the first screen properly with buttons and text view

当我运行应用程序时,它会使用按钮和文本视图正确显示第一个屏幕

But when loaded next page on button press it shows blank screen. Please help.

但是当按下按钮的下一页时,它会显示空白屏幕。请帮忙。

3 个解决方案

#1

use "protected void onCreate(Bundle savedInstanceState)" method instead of "public void onCreate(Bundle savedInstanceState, PersistableBundle persistentState)"

使用“protected void onCreate(Bundle savedInstanceState)”方法而不是“public void onCreate(Bundle savedInstanceState,PersistableBundle persistentState)”

#2

<activity
            android:name="secondActivity"
            android:label="New Page"
    />

change this code and try

更改此代码并尝试

  <activity
            android:name=".secondActivity"
            android:label="New Page"
    />

#3

You are missing a . (dot) in front of activity declaration in manifest for second activity.

你错过了。 (点)在第二个活动的清单中的活动声明前面。

 <activity
            android:name="secondActivity"
            android:label="New Page"
    />

it should be

它应该是

<activity
            android:name=".secondActivity"
            android:label="New Page"
    />

Edit: For you second activity try to change onCreate method to

编辑:对于您的第二个活动尝试将onCreate方法更改为

@Override
    protected void onCreate(Bundle savedInstanceState) {
         // TODO: Implement this method
    super.onCreate(savedInstanceState);
    setContentView(R.layout.second);
    }

Check if it helps

检查是否有帮助

#1