两天来,我一直在尝试使该setVisibility(View.INVISIBLE)
功能正常工作。但是如果我在模拟器中测试我的应用程序,它总是会崩溃。怎么了?(还有:视图arg0
和视图之间v
有什么区别onClickListener
?)
public class SpielActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_spiel);
final Button startbutton = (Button)findViewById(R.id.anfangsbutton);
final TextView initCountdown = (TextView)findViewById(R.id.initcountdown);
startbutton.setVisibility(View.VISIBLE);
startbutton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
startbutton.setVisibility(View.INVISIBLE);
new CountDownTimer(3500, 1000) {
public void onTick(long millisUntilFinished) {
initCountdown.setText("" + millisUntilFinished / 1000);
}
public void onFinish() {
initCountdown.setText("");
}
}.start();
}
});
}
}
这是 LogCat 数据:
02-12 14:18:30.147: W/dalvikvm(332): threadid=1: thread exiting with uncaught exception (group=0x40015560)
02-12 14:18:30.147: E/AndroidRuntime(332): FATAL EXCEPTION: main
02-12 14:18:30.147: E/AndroidRuntime(332): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.JodomStudios.cloudgame/com.JodomStudios.cloudgame.SpielActivity}: java.lang.ClassCastException: android.widget.ImageButton
02-12 14:18:30.147: E/AndroidRuntime(332): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
02-12 14:18:30.147: E/AndroidRuntime(332): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
02-12 14:18:30.147: E/AndroidRuntime(332): at android.app.ActivityThread.access(ActivityThread.java:117)
02-12 14:18:30.147: E/AndroidRuntime(332): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
02-12 14:18:30.147: E/AndroidRuntime(332): at android.os.Handler.dispatchMessage(Handler.java:99)
02-12 14:18:30.147: E/AndroidRuntime(332): at android.os.Looper.loop(Looper.java:123)
02-12 14:18:30.147: E/AndroidRuntime(332): at android.app.ActivityThread.main(ActivityThread.java:3683)
02-12 14:18:30.147: E/AndroidRuntime(332): at java.lang.reflect.Method.invokeNative(Native Method)
02-12 14:18:30.147: E/AndroidRuntime(332): at java.lang.reflect.Method.invoke(Method.java:507)
02-12 14:18:30.147: E/AndroidRuntime(332): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
02-12 14:18:30.147: E/AndroidRuntime(332): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
02-12 14:18:30.147: E/AndroidRuntime(332): at dalvik.system.NativeStart.main(Native Method)
02-12 14:18:30.147: E/AndroidRuntime(332): Caused by: java.lang.ClassCastException: android.widget.ImageButton
02-12 14:18:30.147: E/AndroidRuntime(332): at com.JodomStudios.cloudgame.SpielActivity.onCreate(SpielActivity.java:19)
02-12 14:18:30.147: E/AndroidRuntime(332): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
02-12 14:18:30.147: E/AndroidRuntime(332): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
02-12 14:18:30.147: E/AndroidRuntime(332): ... 11 more
这是xml布局
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/linearlayoutspiel"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/backgroundleiter"
android:orientation="vertical" >
<TextView
android:id="@+id/zeitzaehler"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:text="@string/countdown"
android:textAppearance="?android:attr/textAppearanceMedium" />
<Button
android:id="@+id/menubutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:text="@string/menu" />
<Button
android:id="@+id/contbutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:text="@string/cont" />
<ImageButton
android:id="@+id/pausebutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:background="#00000000"
android:src="@drawable/closebutton" />
<TextView
android:id="@+id/initcountdown"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:text="@string/initcountdown"
android:textAppearance="?android:attr/textAppearanceLarge"
android:textSize="40sp" />
<ImageButton
android:id="@+id/retrybutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_toLeftOf="@+id/pausebutton"
android:background="#00000000"
android:src="@drawable/zeichnung" />
<Button
android:id="@+id/anfangsbutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="@+id/menubutton"
android:layout_centerHorizontal="true"
android:layout_marginBottom="18dp"
android:text="@string/startgame" />
</RelativeLayout>