安卓教程 'HelloTabWidget'

Question

我想我已经完全按照 android 选项卡布局教程中的说明添加了代码并更正了所有问题。该应用程序似乎编译正常，但当我在模拟器上运行它时，它显示“应用程序 * 意外停止，请重试”。这是我的文件，如果您发现代码有任何问题，请告诉我。

有 4 个独立的 Activity 文件。

package com.example.HelloTabWidget;


import android.app.TabActivity;
import android.content.Intent;
import android.content.res.Resources;
import android.os.Bundle;
import android.widget.*;

public class AlbumsActivity extends TabActivity {
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    Resources res = getResources(); // Resource object to get Drawables
    TabHost tabHost = getTabHost();  // The activity TabHost
    TabHost.TabSpec spec;  // Resusable TabSpec for each tab
    Intent intent;  // Reusable Intent for each tab

    // Create an Intent to launch an Activity for the tab (to be reused)
    intent = new Intent().setClass(this, ArtistsActivity.class);

    // Initialize a TabSpec for each tab and add it to the TabHost
    spec = tabHost.newTabSpec("artists").setIndicator("Artists",
                      res.getDrawable(R.drawable.ic_tab_artists))
                  .setContent(intent);
    tabHost.addTab(spec);

    // Do the same for the other tabs
    intent = new Intent().setClass(this, AlbumsActivity.class);
    spec = tabHost.newTabSpec("albums").setIndicator("Albums",
                      res.getDrawable(R.drawable.ic_tab_artists_grey))
                  .setContent(intent);
    tabHost.addTab(spec);

    intent = new Intent().setClass(this, SongsActivity.class);
    spec = tabHost.newTabSpec("songs").setIndicator("Songs",
                      res.getDrawable(R.drawable.ic_tab_artists_white))
                  .setContent(intent);
    tabHost.addTab(spec);

    tabHost.setCurrentTab(2);
}



}

package com.example.HelloTabWidget;

import android.app.TabActivity;
import android.content.Intent;
import android.content.res.Resources;
import android.os.Bundle;
import android.widget.TabHost;

public class ArtistsActivity extends TabActivity {
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    Resources res = getResources(); // Resource object to get Drawables
    TabHost tabHost = getTabHost();  // The activity TabHost
    TabHost.TabSpec spec;  // Resusable TabSpec for each tab
    Intent intent;  // Reusable Intent for each tab

    // Create an Intent to launch an Activity for the tab (to be reused)
    intent = new Intent().setClass(this, ArtistsActivity.class);

    // Initialize a TabSpec for each tab and add it to the TabHost
    spec = tabHost.newTabSpec("artists").setIndicator("Artists",
                      res.getDrawable(R.drawable.ic_tab_artists))
                  .setContent(intent);
    tabHost.addTab(spec);

    // Do the same for the other tabs
    intent = new Intent().setClass(this, AlbumsActivity.class);
    spec = tabHost.newTabSpec("albums").setIndicator("Albums",
                      res.getDrawable(R.drawable.ic_tab_artists_grey))
                  .setContent(intent);
    tabHost.addTab(spec);

    intent = new Intent().setClass(this, SongsActivity.class);
    spec = tabHost.newTabSpec("songs").setIndicator("Songs",
                      res.getDrawable(R.drawable.ic_tab_artists_white))
                  .setContent(intent);
    tabHost.addTab(spec);

    tabHost.setCurrentTab(2);
}

}


package com.example.HelloTabWidget;

import android.app.TabActivity;
import android.content.Intent;
import android.content.res.Resources;
import android.os.Bundle;
import android.widget.TabHost;

public class HelloTabWidget extends TabActivity {
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    Resources res = getResources(); // Resource object to get Drawables
    TabHost tabHost = getTabHost();  // The activity TabHost
    TabHost.TabSpec spec;  // Resusable TabSpec for each tab
    Intent intent;  // Reusable Intent for each tab

    // Create an Intent to launch an Activity for the tab (to be reused)
    intent = new Intent().setClass(this, ArtistsActivity.class);

    // Initialize a TabSpec for each tab and add it to the TabHost
    spec = tabHost.newTabSpec("artists").setIndicator("Artists",
                      res.getDrawable(R.drawable.ic_tab_artists))
                  .setContent(intent);
    tabHost.addTab(spec);

    // Do the same for the other tabs
    intent = new Intent().setClass(this, AlbumsActivity.class);
    spec = tabHost.newTabSpec("albums").setIndicator("Albums",
                      res.getDrawable(R.drawable.ic_tab_artists_grey))
                  .setContent(intent);
    tabHost.addTab(spec);

    intent = new Intent().setClass(this, SongsActivity.class);
    spec = tabHost.newTabSpec("songs").setIndicator("Songs",
                      res.getDrawable(R.drawable.ic_tab_artists_white))
                  .setContent(intent);
    tabHost.addTab(spec);

    tabHost.setCurrentTab(2);
}}




 package com.example.HelloTabWidget;


import android.app.TabActivity;
import android.content.Intent;
import android.content.res.Resources;
import android.os.Bundle;
import android.widget.TabHost;

public class SongsActivity extends TabActivity {
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    Resources res = getResources(); // Resource object to get Drawables
    TabHost tabHost = getTabHost();  // The activity TabHost
    TabHost.TabSpec spec;  // Resusable TabSpec for each tab
    Intent intent;  // Reusable Intent for each tab

    // Create an Intent to launch an Activity for the tab (to be reused)
    intent = new Intent().setClass(this, ArtistsActivity.class);

    // Initialize a TabSpec for each tab and add it to the TabHost
    spec = tabHost.newTabSpec("artists").setIndicator("Artists",
                      res.getDrawable(R.drawable.ic_tab_artists))
                  .setContent(intent);
    tabHost.addTab(spec);

    // Do the same for the other tabs
    intent = new Intent().setClass(this, AlbumsActivity.class);
    spec = tabHost.newTabSpec("albums").setIndicator("Albums",
                      res.getDrawable(R.drawable.ic_tab_artists_grey))
                  .setContent(intent);
    tabHost.addTab(spec);

    intent = new Intent().setClass(this, SongsActivity.class);
    spec = tabHost.newTabSpec("songs").setIndicator("Songs",
                      res.getDrawable(R.drawable.ic_tab_artists_white))
                  .setContent(intent);
    tabHost.addTab(spec);

    tabHost.setCurrentTab(2);
}}

这是 res/drawable 中的艺术家 xml 文件(图像也存在于 res/drawable 中)

 <?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<!-- When selected, use grey -->
<item android:drawable="@drawable/ic_tab_artists_grey"
      android:state_selected="true" />
<!-- When not selected, use white-->
<item android:drawable="@drawable/ic_tab_artists_white" />
</selector>

这是main.xml

 <?xml version="1.0" encoding="utf-8"?>
<TabHost xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@android:id/tabhost"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:padding="5dp">
    <TabWidget
        android:id="@android:id/tabs"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />
    <FrameLayout
        android:id="@android:id/tabcontent"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:padding="5dp" />
</LinearLayout>
</TabHost>

这是android list 文件

  <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.HelloTabWidget" android:versionCode="1"
android:versionName="1.0">
<uses-sdk android:minSdkVersion="7" />
<application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name=".HelloTabWidget" android:label="@string/app_name"
android:theme="@android:style/Theme.NoTitleBar">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>
<activity android:name=".AlbumsActivity" android:label="@string/app_name"
    android:theme="@android:style/Theme.NoTitleBar">

</activity>
<activity android:name=".ArtistsActivity" android:label="@string/app_name"
    android:theme="@android:style/Theme.NoTitleBar">

</activity>
<activity android:name=".SongsActivity" android:label="@string/app_name"
    android:theme="@android:style/Theme.NoTitleBar">

</activity>
</application>


</manifest>

我花了很长时间研究这个问题，寻找拼写错误，但一无所获，我也花了很长时间在论坛上寻找，但似乎没有什么能充分说明为什么这不起作用——尽管我是新手，所以可能会弄错，也许不明白答案，但我不认为那是它。

Answer 1

目前，您所有的 Activity.java 类看起来与它们可能不应该的 HelloTabWidget.java 完全一样

尝试:

HelloTabWidget.java

package com.example.HelloTabWidget;

import android.app.TabActivity;
import android.content.Intent;
import android.content.res.Resources;
import android.os.Bundle;
import android.widget.TabHost;

public class HelloTabWidget extends TabActivity {
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    Resources res = getResources(); 
    TabHost tabHost = getTabHost();  

    tabHost.addTab(tabHost.newTabSpec("artists").setIndicator("Artists",res.getDrawable(R.drawable.ic_tab_artists)).setContent(new Intent(this, ArtistsActivity.class)));
    tabHost.addTab(tabHost.newTabSpec("albums").setIndicator("Albums",res.getDrawable(R.drawable.ic_tab_artists)).setContent(new Intent(this, AlbumsActivity.class)));
    tabHost.addTab(tabHost.newTabSpec("songs").setIndicator("Songs",res.getDrawable(R.drawable.ic_tab_artists)).setContent(new Intent(this, SongsActivity.class)));

    tabHost.setCurrentTab(2);
    }
}

ArtistsActivity.java

package com.example.HelloTabWidget;

import android.app.Activity;
import android.os.Bundle;


public class ArtistsActivity extends Activity {
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.artistslayout);

    // your code for this activity ... (not the same as HelloTabWidget.java)


    }
}

其他 2 个 Activity 类也是如此。