尝试为imageview设置Image时无法恢复活动

Question

感谢的关注

当我尝试在恢复活动上为图像视图设置图像时，我仍然被卡住

public class CardActivity extends Activity {
public static class CardType {
    public static String Owner = "owner";
    public static String VIP = "vip";
    public static String Staff = "staff";
    public static String Normal = "white";
}
private static ViewConfiguration vc = null;
private static int SWIPE_MIN_DISTANCE = 120;
private static int SWIPE_THRESHOLD_VELOCITY = 200;
private GestureDetector gestureDetector;
View.OnTouchListener gestureListener;
Context context;
ErrorHandle errHandle = null;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    context = getApplicationContext();
    if (MainActivity.MainPreferences == null) {
        MainActivity.MainPreferences = new AppPreferences(context);
    }
    // Halt all the autosaved function
    MainActivity.MainPreferences.putAutoSavedData(false);
    errHandle = new ErrorHandle(this);
    // Set the screen layout first
    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 
                            WindowManager.LayoutParams.FLAG_FULLSCREEN);
    // Show the content
    assign_layout();
    setup_Gesture();
}
@Override
public synchronized void onResume() {
    errHandle.showDebugToast("CardActivity.onResume", "Start");
    super.onResume();
    assign_MembershipData();
}
@Override
public synchronized void onPause() {
    super.onPause();
}
@Override
public void onDestroy() {
    errHandle.showDebugToast("CardActivity.onDestroy", "Start");
    super.onDestroy();
}
private void assign_layout() {
    String cardTypeText = MainActivity.MainPreferences.getCardType();
    TextView fullName_text = (TextView) findViewById(R.id.textFullName);
    TextView cardNumber_text = (TextView) findViewById(R.id.textCardNumber);
    try {
        if (cardTypeText.equalsIgnoreCase(CardType.Owner)) {
            setContentView(R.layout.activity_card_owner);
            fullName_text.setTextColor(Color.WHITE);
            cardNumber_text.setTextColor(Color.WHITE);
        } else if (cardTypeText.equalsIgnoreCase(CardType.VIP)) {
            setContentView(R.layout.activity_card_vip);
        } else if (cardTypeText.equalsIgnoreCase(CardType.Staff)) {
            setContentView(R.layout.activity_card_staff);
        }  else {
            setContentView(R.layout.activity_card);
        }
    } catch (Exception e) {
        // TODO e
    }
}
private void assign_MembershipData() {
    errHandle.showDebugToast("CardActivity.assign_MembershipData", "Start");
    Bitmap bitmap = null;
    // Get the message from the intent
    //Intent intent = getIntent();
    String fullName = MainActivity.MainPreferences.getFullName();
    String cardNumber = MainActivity.MainPreferences.getMemberNumber().replace("-", " ");
    String email = MainActivity.MainPreferences.getEmailAddress();
    Typeface font = Typeface.createFromAsset(getAssets(), "cynthe.ttf");  
    TextView fullName_text = (TextView) findViewById(R.id.textFullName);
    fullName_text.setTypeface(font);
    fullName_text.setText(fullName);
    ImageView qr_code_image = (ImageView) findViewById(R.id.qr_code_image_barcode);
    qr_code_image.setBackgroundResource(R.drawable.ic_archi2);
    TextView cardNumber_text = (TextView) findViewById(R.id.textCardNumber);
    cardNumber_text.setTypeface(font);
    cardNumber_text.setText(cardNumber);    }
private void setup_Gesture() {
    // Gesture setup
    vc = ViewConfiguration.get(context);
    SWIPE_MIN_DISTANCE = vc.getScaledTouchSlop();
    SWIPE_THRESHOLD_VELOCITY = vc.getScaledMinimumFlingVelocity();
    // Gesture detection
    gestureDetector = new GestureDetector(this, new CardGestureDetector());
    gestureListener = new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            return gestureDetector.onTouchEvent(event);
        }
    };
    ImageView imageCard = (ImageView) findViewById(R.id.imageCard);
    imageCard.setClickable(true);
    imageCard.setOnTouchListener(gestureListener);
}
public void close_VirtualCard() {
    Intent intent = new Intent();
    setResult(RESULT_OK, intent);
    // Reactivate all the autosaved function
    MainActivity.MainPreferences.putAutoSavedData(true);
    finish();
}
class CardGestureDetector extends SimpleOnGestureListener {
    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
        try {
            // right to left swipe
            if(e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                errHandle.showDebugToast("CardGestureDetector.onFling", "Right to Left");
                close_VirtualCard();
            } else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                errHandle.showDebugToast("CardGestureDetector.onFling", "Left to right");
                close_VirtualCard();
            } else if(e1.getY() - e2.getY() > SWIPE_MIN_DISTANCE && Math.abs(velocityY) > SWIPE_THRESHOLD_VELOCITY) {
                errHandle.showDebugToast("CardGestureDetector.onFling", "Up to down");
                close_VirtualCard();
            } else if (e2.getY() - e1.getY() > SWIPE_MIN_DISTANCE && Math.abs(velocityY) > SWIPE_THRESHOLD_VELOCITY) {
                errHandle.showDebugToast("CardGestureDetector.onFling", "down to up");
                close_VirtualCard();
            }
        } catch (Exception e) {
            // nothing
        }
        return false;
    }
}}

我得到这个错误

04-17 11:37:15.562: E/AndroidRuntime(15922): FATAL EXCEPTION: main
04-17 11:37:15.562: E/AndroidRuntime(15922): java.lang.RuntimeException: Unable to resume activity {package.name/package.name.CardActivity}: java.lang.NullPointerException
04-17 11:37:15.562: E/AndroidRuntime(15922):    at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2613)
04-17 11:37:15.562: E/AndroidRuntime(15922):    at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2641)
04-17 11:37:15.562: E/AndroidRuntime(15922):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2127)
04-17 11:37:15.562: E/AndroidRuntime(15922):    at android.app.ActivityThread.access$600(ActivityThread.java:140)
04-17 11:37:15.562: E/AndroidRuntime(15922):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1228)
04-17 11:37:15.562: E/AndroidRuntime(15922):    at android.os.Handler.dispatchMessage(Handler.java:99)
04-17 11:37:15.562: E/AndroidRuntime(15922):    at android.os.Looper.loop(Looper.java:137)
04-17 11:37:15.562: E/AndroidRuntime(15922):    at android.app.ActivityThread.main(ActivityThread.java:4895)
04-17 11:37:15.562: E/AndroidRuntime(15922):    at java.lang.reflect.Method.invokeNative(Native Method)
04-17 11:37:15.562: E/AndroidRuntime(15922):    at java.lang.reflect.Method.invoke(Method.java:511)
04-17 11:37:15.562: E/AndroidRuntime(15922):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:994)
04-17 11:37:15.562: E/AndroidRuntime(15922):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:761)
04-17 11:37:15.562: E/AndroidRuntime(15922):    at dalvik.system.NativeStart.main(Native Method)
04-17 11:37:15.562: E/AndroidRuntime(15922): Caused by: java.lang.NullPointerException
04-17 11:37:15.562: E/AndroidRuntime(15922):    at package.name.CardActivity.assign_MembershipData(CardActivity.java:136)
04-17 11:37:15.562: E/AndroidRuntime(15922):    at package.name.CardActivity.onResume(CardActivity.java:84)
04-17 11:37:15.562: E/AndroidRuntime(15922):    at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1199)
04-17 11:37:15.562: E/AndroidRuntime(15922):    at android.app.Activity.performResume(Activity.java:5237)
04-17 11:37:15.562: E/AndroidRuntime(15922):    at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2603)

XML

    <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    style="@style/SplashScreen"
    android:layout_width="fill_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    android:gravity="fill" >
    <ImageView
        android:id="@+id/imageCard"
        style="@style/SplashScreen"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:contentDescription="@string/auto_small_text"
        android:scaleType="fitXY"
        android:src="@drawable/member_card_vip" />
    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_marginRight="30dp"
        android:gravity="right"
        android:orientation="vertical" >
        <TextView
            android:id="@+id/textFullName"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="15dp"
            android:gravity="right"
            android:padding="0dp"
            android:text="@string/membercard_fullname"
            android:textColor="@color/LightGoldenrodYellow"
            android:textSize="@dimen/vcard_text_normal" />
        <TextView
            android:id="@+id/textCardNumber"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="-15dp"
            android:gravity="right"
            android:padding="0dp"
            android:text="@string/membercard_number"
            android:textColor="@color/LightGoldenrodYellow"
            android:textSize="@dimen/vcard_number_normal" />
    </LinearLayout>
    <ImageView
        android:id="@+id/qr_code_image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:layout_marginRight="17dp"
        android:layout_marginTop="10dp" />
</RelativeLayout>

它在高规格设备中运行良好，但当我尝试在低内存设备中运行时出错

Answer 1

确保在assign_layout()方法中调用setContentView(R.layout.name);方法后初始化所有布局。

只需更改您的方法如下：

private void assign_layout() {
    String cardTypeText = MainActivity.MainPreferences.getCardType();
       try {
        if (cardTypeText.equalsIgnoreCase(CardType.Owner)) {
            setContentView(R.layout.activity_card_owner);
            fullName_text.setTextColor(Color.WHITE);
            cardNumber_text.setTextColor(Color.WHITE);
        } else if (cardTypeText.equalsIgnoreCase(CardType.VIP)) {
            setContentView(R.layout.activity_card_vip);
        } else if (cardTypeText.equalsIgnoreCase(CardType.Staff)) {
            setContentView(R.layout.activity_card_staff);
        }  else {
            setContentView(R.layout.activity_card);
        }
    TextView fullName_text = (TextView) findViewById(R.id.textFullName);
    TextView cardNumber_text = (TextView) findViewById(R.id.textCardNumber);
    } catch (Exception e) {
        // TODO e
    }
}

我建议您在if循环中初始化视图，因为您正在根据条件膨胀不同的布局。因此，您的视图将始终基于膨胀的布局进行初始化。因此，从assign_MembershipData()中删除所有视图初始化，并根据视图所在的布局将其移动到assign_layout()中。