package com.example.Lovisis;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.animation.AccelerateInterpolator;
import android.view.animation.Animation;
import android.widget.Button;
import com.yashpoolla.Lovisis.R;
public class MainActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button a = (Button) findViewById(R.id.button3);
a.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
//TODO Auto-generated method stub
gotoScreen1();//startActivity(new Intent(MainActivity.this, AlarmInput.class));
}
});
Button b = (Button) findViewById(R.id.button2);
b.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
gotoScreen2();//startActivity(new Intent(MainActivity.this, Cbdata.class));
}
});
Button c = (Button) findViewById(R.id.button1);
c.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
//gotoScreen4();//startActivity(new Intent(MainActivity.this, Help.class));
}
});
Button d = (Button) findViewById(R.id.Button4);
d.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
//gotoScreen3();//startActivity(new Intent(MainActivity.this, Viewdb.class));
}
});
}
//anim start
/*public boolean onCreateOptionsMenu(Menu menu) {
boolean result = super.onCreateOptionsMenu(menu);
menu.add(0, MENU_SCREEN2, 1, R.string.menu_screen2 );
return result;
}
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
switch( id ) {
case MENU_SCREEN2:
gotoScreen2();
break;
}
return true;
}*/
private void gotoScreen1() {
View g = (View)findViewById( R.id.main);
applyRotation( g,0,90, new GotoNextActivity1());
}
private void gotoScreen2() {
View g = (View)findViewById( R.id.main);
applyRotation( g,0,90, new GotoNextActivity2());
}
private void gotoScreen3() {
View g = (View)findViewById( R.id.main);
applyRotation( g,0,90, new GotoNextActivity3());
}
private void gotoScreen4() {
View g = (View)findViewById( R.id.main);
applyRotation( g,0,90, new GotoNextActivity4());
}
public static void applyRotation(
View container,
float start,
float end,
Animation.AnimationListener animationListener ) {
// Find the center of the container
final float centerX = container.getWidth()/2.0f;
final float centerY = container.getHeight()/2.0f;
// Create a new 3D rotation with the supplied parameter
// The animation listener is used to trigger the next animation
final Rotate3dAnimation rotation =
new Rotate3dAnimation(start, end, centerX, centerY, 10.0f, true);
rotation.setDuration(500);
rotation.setFillAfter(true);
rotation.setInterpolator(new AccelerateInterpolator());
if( animationListener != null )
rotation.setAnimationListener( animationListener );
container.startAnimation(rotation);
}
private final class GotoNextActivity1 implements Animation.AnimationListener {
public void onAnimationStart(Animation animation) {
}
public void onAnimationEnd(Animation animation) {
startActivity(new Intent(MainActivity.this, AlarmInput.class));
overridePendingTransition( 0,0 );
}
public void onAnimationRepeat(Animation animation) {
}
}
private final class GotoNextActivity2 implements Animation.AnimationListener {
public void onAnimationStart(Animation animation) {
}
public void onAnimationEnd(Animation animation) {
startActivity(new Intent(MainActivity.this, Cbdata.class));
overridePendingTransition( 0,0 );
}
public void onAnimationRepeat(Animation animation) {
}
}
private final class GotoNextActivity3 implements Animation.AnimationListener {
public void onAnimationStart(Animation animation) {
}
public void onAnimationEnd(Animation animation) {
startActivity(new Intent(MainActivity.this, Viewdb.class));
overridePendingTransition( 0,0 );
}
public void onAnimationRepeat(Animation animation) {
}
}
private final class GotoNextActivity4 implements Animation.AnimationListener {
public void onAnimationStart(Animation animation) {
}
public void onAnimationEnd(Animation animation) {
startActivity(new Intent(MainActivity.this, Help.class));
overridePendingTransition( 0,0 );
}
public void onAnimationRepeat(Animation animation) {
}
}
//anim end
}
清单：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.yashpoolla.Lovisis"
android:versionCode="3"
android:versionName="1.3" >
<uses-sdk
android:minSdkVersion="8"/>
<uses-permission android:name="android.permission.SEND_SMS" />
<uses-permission android:name="android.permission.RECEIVE_SMS" />
<uses-permission android:name="android.permission.RECEIVE_SMS" />
<uses-permission android:name="android.permission.CALL_PHONE" />
<uses-permission android:name="android.permission.VIBRATE"/>
-
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" android:debuggable="false">
<receiver android:name="com.example.Lovisis.CbReceiver" >
<intent-filter>
<action android:name="android.provider.Telephony.CB_RECEIVED" >
</action>
<action android:name="android.provider.Telephony.SMS_RECEIVED" >
</action>
</intent-filter>
</receiver>
<activity android:name="com.example.Lovisis.Cbdata" >
<intent-filter>
<action
android:name="android.appwidget.action.APPWIDGET_UPDATE"
android:launchMode="singleTop" />
</intent-filter>
</activity>
<activity
android:name="com.example.Lovisis.MainActivity"
android:label="@string/title_activity_main" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<action android:name="android.provider.Telephony.CB_RECEIVED" />
</intent-filter>
</activity>
<activity android:name="com.example.Lovisis.AlarmListner" />
<activity android:name="com.example.Lovisis.Help" />
<activity android:name="com.example.Lovisis.Viewdb" />
<activity android:name="com.example.Lovisis.Sms" />
<activity android:name="com.example.Lovisis.CbReceiver" />
<activity android:name="com.example.Lovisis.AlarmInput" />
<activity android:name="com.example.Lovisis.Manual" />
<activity
android:name="com.example.Lovisis.AlarmAlert"
android:label="@string/title_activity_alarm_alert" >
</activity>
<activity android:name="com.example.Lovisis.splash">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
logcat的：
**04-17 15:14:26.599: D/AndroidRuntime(3024): Shutting down VM
04-17 15:14:26.599: W/dalvikvm(3024): threadid=1: thread exiting with uncaught exception (group=0x40018578)
04-17 15:14:26.599: E/AndroidRuntime(3024): FATAL EXCEPTION: main
04-17 15:14:26.599: E/AndroidRuntime(3024): java.lang.NullPointerException
04-17 15:14:26.599: E/AndroidRuntime(3024): at com.example.Lovisis.MainActivity.applyRotation(MainActivity.java:112)
04-17 15:14:26.599: E/AndroidRuntime(3024): at com.example.Lovisis.MainActivity.gotoScreen1(MainActivity.java:88)
04-17 15:14:26.599: E/AndroidRuntime(3024): at com.example.Lovisis.MainActivity.access$0(MainActivity.java:86)
04-17 15:14:26.599: E/AndroidRuntime(3024): at com.example.Lovisis.MainActivity$1.onClick(MainActivity.java:29)
04-17 15:14:26.599: E/AndroidRuntime(3024): at android.view.View.performClick(View.java:2485)
04-17 15:14:26.599: E/AndroidRuntime(3024): at android.view.View$PerformClick.run(View.java:9080)
04-17 15:14:26.599: E/AndroidRuntime(3024): at android.os.Handler.handleCallback(Handler.java:587)
04-17 15:14:26.599: E/AndroidRuntime(3024): at android.os.Handler.dispatchMessage(Handler.java:92)
04-17 15:14:26.599: E/AndroidRuntime(3024): at android.os.Looper.loop(Looper.java:130)
04-17 15:14:26.599: E/AndroidRuntime(3024): at android.app.ActivityThread.main(ActivityThread.java:3687)
04-17 15:14:26.599: E/AndroidRuntime(3024): at java.lang.reflect.Method.invokeNative(Native Method)
04-17 15:14:26.599: E/AndroidRuntime(3024): at java.lang.reflect.Method.invoke(Method.java:507)
04-17 15:14:26.599: E/AndroidRuntime(3024): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
04-17 15:14:26.599: E/AndroidRuntime(3024): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625)
04-17 15:14:26.599: E/AndroidRuntime(3024): at dalvik.system.NativeStart.main(Native Method)**
我正在尝试在上面给出的活动中按钮点击发生的活动之间切换，它工作正常，突然它开始抛出空指针异常。请帮助我。
答案 0 :(得分：1)
猜猜，但是
(View)findViewById( R.id.main);
可以在将null传递给applyRotation，然后line 112
final float centerX = container.getWidth() / 2.0f;
NullPointerException会抛出main
仔细检查所有相关活动中是否存在ID为{{1}}的视图。
答案 1 :(得分：0)
很抱歉，实际上我为两个布局定义了相同的名称，导致空指针异常，无论如何感谢您的支持..