NineOldAndroids动画无法在API> 10上运行
我正在使用NineOldAndroid库来执行动画。 动画适用于API 10，应用程序强制关闭。 这是我的代码：
import static com.nineoldandroids.view.ViewPropertyAnimator.animate; import android.content.Intent; import android.graphics.Canvas; import android.graphics.PixelFormat; import android.os.Build; import android.os.Bundle; import android.view.KeyEvent; import android.view.View; import android.view.ViewTreeObserver.OnGlobalLayoutListener; import android.view.WindowManager; import android.widget.ImageView; import android.widget.LinearLayout; import android.widget.RelativeLayout; import android.widget.TextView; import com.actionbarsherlock.app.ActionBar; import com.actionbarsherlock.view.MenuItem; import com.nineoldandroids.animation.Animator; import com.nineoldandroids.animation.Animator.AnimatorListener; import com.nineoldandroids.animation.ObjectAnimator; public class ActivityActualMain extends SherlockActivity { LinearLayout container1, container2; RelativeLayout viewTree; ImageView image, image1, image2; TextView tv, tv1, tv2, tv3, tv4; ObjectAnimator anim; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); final int duration = 2000; setContentView(R.layout.activity_actual_main); ActionBar bar = getSupportActionBar(); bar.setDisplayHomeAsUpEnabled(true); bar.setBackgroundDrawable(getResources().getDrawable( R.drawable.red_actionbar)); viewTree = (RelativeLayout) findViewById(R.id.viewTree); container1 = (LinearLayout) findViewById(R.id.linearLayout1); container2 = (LinearLayout) findViewById(R.id.linearLayout2); image = (ImageView) findViewById(R.id.imageView1); image1 = (ImageView) findViewById(R.id.imageView2); image2 = (ImageView) findViewById(R.id.imageView3); tv = (TextView) findViewById(R.id.text_tech_des); viewTree.getViewTreeObserver().addOnGlobalLayoutListener(//to check if the layout has been placed in activity new OnGlobalLayoutListener() { public void onGlobalLayout() { if (Build.VERSION.SDK_INT < 16) { viewTree.getViewTreeObserver().removeGlobalOnLayoutListener(this);} else{ viewTree.getViewTreeObserver() .removeOnGlobalLayoutListener(this); } anim = ObjectAnimator.ofFloat(image, "y", 0f, image.getTop()); anim.addListener(new AnimatorListener() { @Override public void onAnimationStart(Animator arg0) { // TODO Auto-generated method stub ObjectAnimator.ofFloat(tv, "alpha", 1, 0, 1) .setDuration(duration).start();//line no 82 ObjectAnimator.ofFloat(container1, "x", 0f, container1.getLeft()).setDuration(1000).start(); ObjectAnimator.ofFloat(container2, "x", 0f, container2.getLeft()).setDuration(1000).start(); } @Override public void onAnimationRepeat(Animator arg0) { // TODO Auto-generated method stub } @Override public void onAnimationEnd(Animator arg0) { // TODO Auto-generated method stub } @Override public void onAnimationCancel(Animator arg0) { // TODO Auto-generated method stub } }); anim.setDuration(duration).start();//line no 106 } }); } }
这是我的堆栈跟踪：
10-26 19:23:15.203: E/AndroidRuntime(21541): FATAL EXCEPTION: main 10-26 19:23:15.203: E/AndroidRuntime(21541): java.lang.NullPointerException 10-26 19:23:15.203: E/AndroidRuntime(21541): at com.nineoldandroids.animation.PropertyValuesHolder.setupSetterAndGetter(PropertyValuesHolder.java:523) 10-26 19:23:15.203: E/AndroidRuntime(21541): at com.nineoldandroids.animation.ObjectAnimator.initAnimation(ObjectAnimator.java:410) 10-26 19:23:15.203: E/AndroidRuntime(21541): at com.nineoldandroids.animation.ValueAnimator.setCurrentPlayTime(ValueAnimator.java:538) 10-26 19:23:15.203: E/AndroidRuntime(21541): at com.nineoldandroids.animation.ValueAnimator.start(ValueAnimator.java:928) 10-26 19:23:15.203: E/AndroidRuntime(21541): at com.nineoldandroids.animation.ValueAnimator.start(ValueAnimator.java:951) 10-26 19:23:15.203: E/AndroidRuntime(21541): at com.nineoldandroids.animation.ObjectAnimator.start(ObjectAnimator.java:385) 10-26 19:23:15.203: E/AndroidRuntime(21541): at com.vishalaksh.technex.ActivityActualMain$2$1.onAnimationStart(ActivityActualMain.java:82) 10-26 19:23:15.203: E/AndroidRuntime(21541): at com.nineoldandroids.animation.ValueAnimator.start(ValueAnimator.java:937) 10-26 19:23:15.203: E/AndroidRuntime(21541): at com.nineoldandroids.animation.ValueAnimator.start(ValueAnimator.java:951) 10-26 19:23:15.203: E/AndroidRuntime(21541): at com.nineoldandroids.animation.ObjectAnimator.start(ObjectAnimator.java:385) 10-26 19:23:15.203: E/AndroidRuntime(21541): at com.vishalaksh.technex.ActivityActualMain$2.onGlobalLayout(ActivityActualMain.java:106) 10-26 19:23:15.203: E/AndroidRuntime(21541): at android.view.ViewTreeObserver.dispatchOnGlobalLayout(ViewTreeObserver.java:808) 10-26 19:23:15.203: E/AndroidRuntime(21541): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1768) 10-26 19:23:15.203: E/AndroidRuntime(21541): at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1004) 10-26 19:23:15.203: E/AndroidRuntime(21541): at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5481) 10-26 19:23:15.203: E/AndroidRuntime(21541): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749) 10-26 19:23:15.203: E/AndroidRuntime(21541): at android.view.Choreographer.doCallbacks(Choreographer.java:562) 10-26 19:23:15.203: E/AndroidRuntime(21541): at android.view.Choreographer.doFrame(Choreographer.java:532) 10-26 19:23:15.203: E/AndroidRuntime(21541): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735) 10-26 19:23:15.203: E/AndroidRuntime(21541): at android.os.Handler.handleCallback(Handler.java:730) 10-26 19:23:15.203: E/AndroidRuntime(21541): at android.os.Handler.dispatchMessage(Handler.java:92) 10-26 19:23:15.203: E/AndroidRuntime(21541): at android.os.Looper.loop(Looper.java:137) 10-26 19:23:15.203: E/AndroidRuntime(21541): at android.app.ActivityThread.main(ActivityThread.java:5103) 10-26 19:23:15.203: E/AndroidRuntime(21541): at java.lang.reflect.Method.invokeNative(Native Method) 10-26 19:23:15.203: E/AndroidRuntime(21541): at java.lang.reflect.Method.invoke(Method.java:525) 10-26 19:23:15.203: E/AndroidRuntime(21541): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) 10-26 19:23:15.203: E/AndroidRuntime(21541): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 10-26 19:23:15.203: E/AndroidRuntime(21541): at dalvik.system.NativeStart.main(Native Method)
我在设备API <10上遇到了这个库的问题，它提供了相同的堆栈跟踪。 鉴于我使用的是NineOldAndroids的源代码，我决定调查库内的问题。
经过一些测试后，我注意到发生了这个错误，因为lib试图调用一些视图上不存在的方法（因为它是一个旧的API级别）。 再搜索一下，我找到了AnimatorProxy类，它有一个名为“wrap”的静态方法。 此方法用于将View对象封装在较旧的Android版本中，模拟某些动画方法的存在，如setScaleX / Y，setTransalationX / Y.
要解决这个问题，我必须打开ObjectAnimator类并搜索该行的所有实例（在我的库代码中我发现了4次）：
mTarget = target;
在该类中，我创建了以下方法：
private void setTarget(Object obj) { if (Build.VERSION.SDK_INT < Build.VERSION_CODES.HONEYCOMB && obj instanceof View) { mTarget = AnimatorProxy.wrap((View) obj); } else { mTarget = obj; } }
并用以下代码替换上面的行：
setTarget(target);
不知道它是否可以解决你的问题，因为你说它发生在API 10+（与我的相反），但它是一个很好的起点。