我正在爲小孩子們編寫一個Android應用程序來學習數學,我正在努力讓用戶在他/她正確回答所有問題時獲得獎品。我在屏幕右側動態添加一些視圖,告訴用戶他/她已經獲得獎勵。 (每個可能的問題選項都有相應的獎勵!)左側用於顯示得分。但是,該應用程序崩潰。我試圖看看調用堆棧,看看我做錯了什麼。但是我的方法都不在調用堆棧中!爲什麼Android會自行崩潰?我做錯了什麼?
java.lang.ClassCastException: android.widget.LinearLayout$LayoutParams cannot be cast to android.widget.FrameLayout$LayoutParams
at android.widget.FrameLayout.onMeasure(FrameLayout.java:315)
at android.widget.ScrollView.onMeasure(ScrollView.java:321)
at android.view.View.measure(View.java:16030)
at android.widget.LinearLayout.measureHorizontal(LinearLayout.java:1034)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:590)
at android.view.View.measure(View.java:16030)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5012)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:314)
at android.view.View.measure(View.java:16030)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5012)
at com.android.internal.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:302)
at android.view.View.measure(View.java:16030)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5012)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:314)
at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2196)
at android.view.View.measure(View.java:16030)
at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1915)
at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1109)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1290)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1009)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5508)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
at android.view.Choreographer.doCallbacks(Choreographer.java:562)
at android.view.Choreographer.doFrame(Choreographer.java:532)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
at android.os.Handler.handleCallback(Handler.java:730)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:213)
at android.app.ActivityThread.main(ActivityThread.java:5225)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:741)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
at dalvik.system.NativeStart.main(Native Method)
請參閱?我的軟件包名稱被稱爲com.smartkidslovemaths
,但它不是一個調用堆棧!我怎麼知道我做錯了什麼地方?
無論如何,我認爲我的一些代碼是相關的。這是在屏幕的右側的佈局:
<ScrollView
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/right_side"
android:orientation="vertical">
</LinearLayout>
</ScrollView>
這裏是我怎麼加的觀點,注意,這個方法被調用的方法onCreate
。
private void displayPrize() {
((LinearLayout)findViewById (R.id.right_side)).setLayoutParams (new LinearLayout.LayoutParams (FrameLayout.LayoutParams.MATCH_PARENT, FrameLayout.LayoutParams.MATCH_PARENT));
TextView text = new TextView (this);
final LinearLayout.LayoutParams textParams =
new LinearLayout.LayoutParams (
ViewGroup.LayoutParams.WRAP_CONTENT, 0, 1F
);
final LinearLayout.LayoutParams imageParams =
new LinearLayout.LayoutParams (
ViewGroup.LayoutParams.MATCH_PARENT, 0, 8F
);
text.setLayoutParams (textParams);
Resources res = getResources();
QuestionOptions options = QuestionsActivity.Options.getOptions();
switch (options.getDigitCount()) {
case 1:
default:
text.setText (res.getText (R.string.earn_star_text));
break;
case 2:
text.setText (res.getText (R.string.earn_badge_text));
break;
case 3:
text.setText (res.getText (R.string.earn_trophy_text));
break;
}
text.setTextSize (res.getDimension (R.dimen.answer_text_size)/4);
((LinearLayout)findViewById (R.id.right_side)).addView (text);
ImageView image = new ImageView (this);
image.setLayoutParams (imageParams);
int resID = QuestionOptionMaps.getOptionsDrawableMap().get (options);
image.setImageResource (resID);
((LinearLayout)findViewById (R.id.right_side)).addView (image);
}
我真的不知道我在哪裏做錯了。或者,也許我是正確的,這只是一個Android的錯誤?
這是一個ClassCastException更換
new LinearLayout.LayoutParams
。某處,它試圖將類型A轉換爲(不相關的)類型B. – Stultuske但它發生在android的內部工作中。我該如何解決這個問題? @Stultuske – Sweeper
將這些'findViewById'調用轉換爲'LinearLayout'的基本原理是什麼? Android告訴你這是不可能的,因爲這些類在運行時並不相關。 – Makoto