链接按钮到下一个Android活动崩溃了应用程序

Question

I am trying to have my app go to activity_vehicle.xml when I click the button at the bottom of the activity_main.xml. When I click it the app crashes and I end up with a lot of junk in my log file. I am running eclipse with the android sdk plugin. As a side note when I try to type text into the text fields its in japanese, and the screen is acting like its turned long ways rather then standing straight up.

Here is the button code taken from activity_main.xml where the button is located

<Button
    android:id="@+id/destination_next_button"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_alignParentRight="true"
    android:layout_marginBottom="22dp"
    android:layout_marginRight="37dp"
    android:text="Next" />

This is my android manifest class where I declared the 2nd activity

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

<uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="18" />

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name="com.google.android.gms.MainActivity"
        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="com.google.android.gms.Vehicle"
        android:label="@string/title_activity_vehicle" >
                        <action android:name="com.google.android.gms.Vehicle" />

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

This is my MainActivity.java file where I set the onclick listener for the button. I assume the new start activity would use the Vechicle.java file I have and not the activity_vehicle.xml file

public class MainActivity extends Activity implements OnClickListener 
{

Button destination_next_button;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    destination_next_button = (Button)findViewById(R.id.destination_next_button);
    destination_next_button.setOnClickListener(this);

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

private void destination_next_buttonClick()
{
    startActivity(new Intent("com.google.android.gms.Vehicle"));
}

@Override
public void onClick(View v) {
    switch (v.getId())
    {
    case R.id.destination_next_button:
        destination_next_buttonClick();
        break;
    }

}

}

When the project is ran the following errors pop up in LogCat I deleted the dates to make sure not many of them took more then 1 line

D/AndroidRuntime(428): Shutting down VM
W/dalvikvm(428): threadid=1: thread exiting with uncaught exception (group=0x40014760)
E/AndroidRuntime(428): FATAL EXCEPTION: main
E/AndroidRuntime(428): android.content.ActivityNotFoundException: No Activity found to handle Intent { act=com.google.android.gms.Vehicle }

E/AndroidRuntime(428):  at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1508)

E/AndroidRuntime(428):  at android.app.Instrumentation.execStartActivity(Instrumentation.java:1382)

E/AndroidRuntime(428):  at android.app.Activity.startActivityForResult(Activity.java:3044)
E/AndroidRuntime(428):  at android.app.Activity.startActivity(Activity.java:3150)
E/AndroidRuntime(428):  at com.google.android.gms.MainActivity.destination_next_buttonClick(MainActivity.java:34)

E/AndroidRuntime(428):  at bsu.edu.cs222.gascalculator.MainActivity.onClick(MainActivity.java:42)

E/AndroidRuntime(428):  at android.view.View.performClick(View.java:3100)
E/AndroidRuntime(428):  at android.view.View$PerformClick.run(View.java:11644)
E/AndroidRuntime(428):  at android.os.Handler.handleCallback(Handler.java:587)
E/AndroidRuntime(428):  at android.os.Handler.dispatchMessage(Handler.java:92)
E/AndroidRuntime(428):  at android.os.Looper.loop(Looper.java:126)
E/AndroidRuntime(428):  at android.app.ActivityThread.main(ActivityThread.java:3997)
E/AndroidRuntime(428):  at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime(428):  at java.lang.reflect.Method.invoke(Method.java:491)
E/AndroidRuntime(428):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)

E/AndroidRuntime(428):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
E/AndroidRuntime(428):  at dalvik.system.NativeStart.main(Native Method)

Answer 1

Change this

  startActivity(new Intent("com.google.android.gms.Vehicle"));

to

  startActivity(new Intent(MainActivity.this,Vehicle.class));

You can use MainActivity.this in a annonymous inner class as in that case this is not a valid context.

java.lang.Object
   ↳    android.content.Context // see this
       ↳    android.content.ContextWrapper
           ↳    android.view.ContextThemeWrapper
               ↳    android.app.Activity //see this

And your MainActivity extends Activtiy

or

  startActivity(new Intent(this,Vehicle.class));

this refers to Activity Context.

Change this

  <activity
    android:name="com.google.android.gms.Vehicle"
    android:label="@string/title_activity_vehicle" >
    <action android:name="com.google.android.gms.Vehicle" />
    <category android:name="android.intent.category.DEFAULT" />
 </activity>

to

  <activity
    android:name="com.google.android.gms.Vehicle"
    android:label="@string/title_activity_vehicle" >
  </activity> 

It is better to change your package name coz if you reference google play services and have imports such as import com.google.android.gms.maps.CameraUpdate; . So its is better you change the package name to something more relevant. ` Use Explicit Intents.

Explicit intents specify the component to start by name (the fully-qualified class name). You'll typically use an explicit intent to start a component in your own app, because you know the class name of the activity or service you want to start. For example, start a new activity in response to a user action or start a service to download a file in the background.

Answer 2

Try this..

Change startActivity(new Intent("com.google.android.gms.Vehicle")); to startActivity(new Intent(MainActivity.this,Vehicle.class));

private void destination_next_buttonClick()
{
    startActivity(new Intent(MainActivity.this,Vehicle.class));
}

Answer 3

Try to Change this line:

startActivity(new Intent("com.google.android.gms.Vehicle"));

to

Intent myIntent = new Intent(MainActivity.this, YourOtherActivity.class);
    startActivity(myIntent); 

Try to Change this

<activity
    android:name="com.google.android.gms.Vehicle"
    android:label="@string/title_activity_vehicle" >
    <action android:name="com.google.android.gms.Vehicle" />
    <category android:name="android.intent.category.DEFAULT" />
 </activity>

to

 <activity
    android:name="com.google.android.gms.Vehicle"
    android:label="@string/title_activity_vehicle" >
  </activity> 

It is better to change your package name. Hope it will helps you.