java - App FC 关于重用可绘制资源

Question

    if (someId.matches("A") || someId.matches("a")) {
        addLetters();
        addIcon(R.drawable.apple);
        addSentence("A is for APPLE");
        btnPlay.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                playTheSound(R.raw.a);
            }
        });
    }
    if (someId.matches("B") || someId.matches("b")) {
        addLetters();
        addIcon(R.drawable.ball);
        addSentence("B is for BALL");
        btnPlay.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                playTheSound(R.raw.a);
            }
        });
    }

public void addIcon(int iconResource) {
    ivLetterIcon.setImageResource(iconResource);
}

第一次加载带有代码的 Activity 时，一切正常。我可以选择字母 A并返回上一个 Activity 并返回信件 A并继续这样做，我的应用程序没有 FC，但是当我选择字母 B 时或字母 A 旁边的任何其他字母我的应用程序 FC。

我的 LogCat 显示以下内容:

08-27 14:58:52.691: E/AndroidRuntime(716): FATAL EXCEPTION: main
08-27 14:58:52.691: E/AndroidRuntime(716): java.lang.OutOfMemoryError
08-27 14:58:52.691: E/AndroidRuntime(716):  at android.graphics.BitmapFactory.nativeDecodeAsset(Native Method)
08-27 14:58:52.691: E/AndroidRuntime(716):  at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:500)
08-27 14:58:52.691: E/AndroidRuntime(716):  at android.graphics.BitmapFactory.decodeResourceStream(BitmapFactory.java:353)
08-27 14:58:52.691: E/AndroidRuntime(716):  at android.graphics.drawable.Drawable.createFromResourceStream(Drawable.java:781)
08-27 14:58:52.691: E/AndroidRuntime(716):  at android.content.res.Resources.loadDrawable(Resources.java:1930)
08-27 14:58:52.691: E/AndroidRuntime(716):  at android.content.res.Resources.getDrawable(Resources.java:659)
08-27 14:58:52.691: E/AndroidRuntime(716):  at android.widget.ImageView.resolveUri(ImageView.java:611)
08-27 14:58:52.691: E/AndroidRuntime(716):  at android.widget.ImageView.setImageResource(ImageView.java:354)
08-27 14:58:52.691: E/AndroidRuntime(716):  at com.test.testing.AlpDisplay.addIcon(AlpDisplay.java:548)
08-27 14:58:52.691: E/AndroidRuntime(716):  at com.test.testing.AlpDisplay.onCreate(AlpDisplay.java:204)
08-27 14:58:52.691: E/AndroidRuntime(716):  at android.app.Activity.performCreate(Activity.java:5008)
08-27 14:58:52.691: E/AndroidRuntime(716):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
08-27 14:58:52.691: E/AndroidRuntime(716):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
08-27 14:58:52.691: E/AndroidRuntime(716):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
08-27 14:58:52.691: E/AndroidRuntime(716):  at android.app.ActivityThread.access$600(ActivityThread.java:130)
08-27 14:58:52.691: E/AndroidRuntime(716):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
08-27 14:58:52.691: E/AndroidRuntime(716):  at android.os.Handler.dispatchMessage(Handler.java:99)
08-27 14:58:52.691: E/AndroidRuntime(716):  at android.os.Looper.loop(Looper.java:137)
08-27 14:58:52.691: E/AndroidRuntime(716):  at android.app.ActivityThread.main(ActivityThread.java:4745)
08-27 14:58:52.691: E/AndroidRuntime(716):  at java.lang.reflect.Method.invokeNative(Native Method)
08-27 14:58:52.691: E/AndroidRuntime(716):  at java.lang.reflect.Method.invoke(Method.java:511)
08-27 14:58:52.691: E/AndroidRuntime(716):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
08-27 14:58:52.691: E/AndroidRuntime(716):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
08-27 14:58:52.691: E/AndroidRuntime(716):  at dalvik.system.NativeStart.main(Native Method)

这里抛出错误:

addIcon(R.drawable.ball);

和

public void addIcon(int iconResource) {
    ivLetterIcon.setImageResource(iconResource);
}

错误行:

08-27 15:00:20.341: E/AndroidRuntime(760):  at com.test.testing.AlpDisplay.addIcon(AlpDisplay.java:548)
08-27 15:00:20.341: E/AndroidRuntime(760):  at com.test.testing.AlpDisplay.onCreate(AlpDisplay.java:204)

是因为我使用的是模拟器吗？

我试图为每个字母使用一个函数来减少程序行。

Answer 1

我发现开发 Android 应用程序的最常见错误之一是

java.lang.OutOfMemoryError

首先，在 XML 布局的父 View 上设置“id”属性:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:id="@+id/RootView">
    ...

然后，在 Activity 的 onDestroy() 方法上，调用 unbindDrawables() 方法传递对父 View 的引用，然后执行 System.gc()。

@Override
protected void onDestroy() {
    super.onDestroy();

    unbindDrawables(findViewById(R.id.RootView));
    System.gc();
}

private void unbindDrawables(View view) {
    if (view.getBackground() != null) {
        view.getBackground().setCallback(null);
    }
    if (view instanceof ViewGroup) {
        for (int i = 0; i < ((ViewGroup) view).getChildCount(); i++) {
            unbindDrawables(((ViewGroup) view).getChildAt(i));
        }
        ((ViewGroup) view).removeAllViews();
    }
}

这对我有用。我希望这有帮助 :)