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该问题已被官方收录

使用第三方工具Luban压缩时，图片无法输出到指定路径

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2

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 图片

class="cursor-pointer"> 文本

该问题已被官方收录

无法打开database中的数据库

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1

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 截图

class="cursor-pointer"> 代码

public class SetAddressFragment extends Fragment {

    private static final String TAG = "SetAddressFragment";
    private static final String DB_NAME = "mydb.db";

    private TextView confirmTV, cancelTV;
    private NumberPicker provinceNP, cityNP, areaNP;
    private AddressManager manager;
    private SendMessageAddress sendMessageAddress;


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle saveInstanceState) {
        View square = inflater.inflate(R.layout.fragment_setaddress, container, false);

        manager = new AddressManager(getContext().getDatabasePath(DB_NAME).getPath());
        initView(square);
        initProvince();
        return square;
    }

......

}

#####################################################################################################################

public class AddressManager {


    private static final String TABLE_NAME = "ssq"; //表名
    private static final String PROVINCE = "province"; //省
    private static final String CITY = "city"; //市
    private static final String AREA = "area"; //区/县

    private SQLiteDatabase database;

    /**
     * @param dbPath 数据库中“省市区”表的路径
     */
    public AddressManager(String dbPath) {
        database = SQLiteDatabase.openOrCreateDatabase(dbPath, null);
    }

    /**
     * 查询所有省份
     *
     * @return 所有的省份名称
     */
    public List<String> getProvinces() {

        String sql = "select distinct " + PROVINCE + " from " + TABLE_NAME;
        Cursor cursor = database.rawQuery(sql, null);
        List<String> provinceList = new ArrayList<>();
        if (cursor != null) {
            while (cursor.moveToNext()) {
                String province = cursor.getString(cursor.getColumnIndex("province"));
                Log.i("tag", "province----->" + province);
                provinceList.add(province);
            }
            cursor.close();
        }
        return provinceList;
    }

    /**
     * 查询指定省份或直辖市的所有市的集合
     *
     * @param province 省份名称
     * @return 查询到的所有城市
     */
    public List<String> getCities(String province) {
        String sql = "select distinct " + CITY + " from " + TABLE_NAME + " where " + PROVINCE + " = ?";
        Cursor cursor = database.rawQuery(sql, new String[]{province});
        List<String> addressList = new ArrayList<>();
        while (cursor.moveToNext()) {
            String city = cursor.getString(cursor.getColumnIndex(CITY));
            Log.i("tag", "city----->" + city);
            addressList.add(city);
        }
        //关闭游标
        cursor.close();
        return addressList;
    }


    /**
     * 查询指定市的所有区的列表的List集合
     *
     * @param city 市的名称
     * @return 查询到的所有区
     */
    public List<String> getAreas(String city) {
        //获取指定市的所有区的列表的sql语句
        String sql = "select distinct " + AREA + " from " + TABLE_NAME + " where " + CITY + " = ?";
        Cursor cursor = database.rawQuery(sql, new String[]{city});
        List<String> addressList = new ArrayList<>();
        while (cursor.moveToNext()) {
            //获取区的名称
            String area = cursor.getString(cursor.getColumnIndex(AREA));
            Log.i("tag", "area----->" + area);
            //把所有的区添加到List集合
            addressList.add(area);
        }
        //关闭游标
        cursor.close();
        return addressList;
    }
}

该问题已被官方收录

使用第三方依赖库时，报错

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class="cursor-pointer"> 详细描述

class="cursor-pointer"> 截图

class="cursor-pointer"> 代码

android {
    compileSdkVersion 28

    packagingOptions {
        exclude 'META-INF/*'
    }

该问题已被官方收录

SwipeRefreshLayout刷新两次才显示数据

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class="cursor-pointer"> 详细描述

class="cursor-pointer"> 截图

class="cursor-pointer"> 代码

public class MyOnRefrshListener implements SwipeRefreshLayout.OnRefreshListener {

        @Override
        public void onRefresh() {

            new Handler().postDelayed(new Runnable() {
                @Override
                public void run() {
                    Toast.makeText(getActivity(), "正在刷新", Toast.LENGTH_SHORT).show();
                    Log.d("通知", "开始查询");
                    //查询数据
                    queryData(0, STATE_REFRESH);

                    Log.d("", "数据查询已完成，通知主线程更新UI");
                    mHandler.sendEmptyMessage(CHANGE_UI);

                    swipeRefreshLayout.setRefreshing(false);
                }
            }, 2000);
        }


    }

该问题已被官方收录

创建了一个View，对其使用setVisibility（）方法，运行时报空指针

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class="cursor-pointer"> 详细描述

class="cursor-pointer"> 截图

2018-11-10 20:41:32.250 25639-25639/? E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.forrestsu.logintest, PID: 25639
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.forrestsu.logintest/com.example.forrestsu.logintest.activity.MapModeActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.view.View.setVisibility(int)' on a null object reference
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2822)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2897)
        at android.app.ActivityThread.-wrap11(Unknown Source:0)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1598)
        at android.os.Handler.dispatchMessage(Handler.java:105)
        at android.os.Looper.loop(Looper.java:251)
        at android.app.ActivityThread.main(ActivityThread.java:6572)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.view.View.setVisibility(int)' on a null object reference
        at com.example.forrestsu.logintest.activity.MapModeActivity.initView(MapModeActivity.java:96)
        at com.example.forrestsu.logintest.activity.MapModeActivity.onCreate(MapModeActivity.java:86)
        at android.app.Activity.performCreate(Activity.java:6975)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1214)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2775)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2897) 
        at android.app.ActivityThread.-wrap11(Unknown Source:0) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1598) 
        at android.os.Handler.dispatchMessage(Handler.java:105) 
        at android.os.Looper.loop(Looper.java:251) 
        at android.app.ActivityThread.main(ActivityThread.java:6572) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767) 
2018-11-10 20:41:32.251 25639-25639/? D/MtaSDK: [main(2): null:61] - MTA has caught the following uncaught exception:
2018-11-10 20:41:32.251 25639-25639/? E/MtaSDK: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.forrestsu.logintest/com.example.forrestsu.logintest.activity.MapModeActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.view.View.setVisibility(int)' on a null object reference
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2822)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2897)
        at android.app.ActivityThread.-wrap11(Unknown Source:0)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1598)
        at android.os.Handler.dispatchMessage(Handler.java:105)
        at android.os.Looper.loop(Looper.java:251)
        at android.app.ActivityThread.main(ActivityThread.java:6572)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.view.View.setVisibility(int)' on a null object reference
        at com.example.forrestsu.logintest.activity.MapModeActivity.initView(MapModeActivity.java:96)
        at com.example.forrestsu.logintest.activity.MapModeActivity.onCreate(MapModeActivity.java:86)
        at android.app.Activity.performCreate(Activity.java:6975)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1214)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2775)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2897) 
        at android.app.ActivityThread.-wrap11(Unknown Source:0) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1598) 
        at android.os.Handler.dispatchMessage(Handler.java:105) 
        at android.os.Looper.loop(Looper.java:251) 
        at android.app.ActivityThread.main(ActivityThread.java:6572) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)

class="cursor-pointer"> 代码

布局文件
<View
        android:id="@+id/glass_view"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:background="@color/transparent"
        android:clickable="true"
        android:focusable="true"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/view_top" />

代码
private View glassView；

......

glassView = (View) findViewById(R.id.view_glass);
glassView.setVisibility(GONE);
        glassView.setOnClickListener(new MyOnClickListener());

该问题已被官方收录

编译时报错: 错误: 找不到符号...... 符号: 类......

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class="cursor-pointer"> 详细描述

class="cursor-pointer"> 截图

class="cursor-pointer"> 代码

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.forrestsu.test">

    <application
        android:name=".myUtils.MyApplication"
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".activity.MainActivity">
            <intent-filter>

                <!-- Deep Link -->
                <action android:name="android.intent.action.VIEW" />
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <service
            android:name=".service.MyService"
            android:enabled="true"
            android:exported="true" />
        <service
            android:name=".service.DownloadService"
            android:enabled="true"
            android:exported="true" />
        <activity android:name=".activity.NotificationTestActivity" />
        <activity android:name=".activity.DownloadTestActivity" />
    </application>

该问题已被官方收录

自定义Notification的布局使用ConstraintLayout时会报错

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class="cursor-pointer"> 详细描述

class="cursor-pointer"> 截图

class="cursor-pointer"> 代码

布局
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <TextView
        android:id="@+id/tv_title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:text="Test"
        android:textColor="@color/black_000000"
        android:textSize="14sp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/tv_content"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:ellipsize="end"
        android:maxLines="3"
        android:text="test"
        android:textColor="@color/grey_555555"
        android:textSize="14sp"
        app:layout_constraintStart_toStartOf="@+id/tv_title"
        app:layout_constraintTop_toBottomOf="@+id/tv_title" />

    <ImageView
        android:id="@+id/iv_ico"
        android:layout_width="60dp"
        android:layout_height="60dp"
        android:layout_alignParentEnd="true"
        android:layout_centerVertical="true"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginBottom="8dp"
        android:src="@mipmap/icon"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

代码
/**
     * 默认通知，有声音提示
     * @param context
     * @param title 通知标题
     * @param content 通知内容
     */
    public static Notification getDefaultNotification(Context context, String title, String content) {
        NotificationCompat.Builder builder;
        if (Build.VERSION.SDK_INT >= 26) {
            initChannel(context);
            builder = new NotificationCompat.Builder(context, "channelWithSound");
        } else {
            builder = new NotificationCompat.Builder(context, null);
        }

        RemoteViews defaultRemoteViews = new RemoteViews(context.getPackageName(),
                R.layout.notification_test_2);
        defaultRemoteViews.setTextViewText(R.id.tv_title, title);
        defaultRemoteViews.setTextViewText(R.id.tv_content, content);

        builder.setCustomContentView(defaultRemoteViews) //设置自定义布局
            .setCustomBigContentView(defaultRemoteViews)
            //.setContentTitle(title) //设置通知标题
            //.setContentText(content) //设置通知内容
            .setWhen(System.currentTimeMillis()) //设置通知时间，这是获取了当前系统时间
            .setSmallIcon(R.drawable.android_black_48_48) //设置通知图标（系统状态栏上显示的小图标）
            //.setDefaults(NotificationCompat.FLAG_ONLY_ALERT_ONCE) //关闭声音、震动
            //.setLights(Color.GREEN, 1000, 1000);//设置呼吸灯
            .setAutoCancel(true); //点击通知后取消显示
        return builder.build();
    }

}

该问题已被官方收录

versionCodeMajor的作用是什么？

0

1

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 截图

class="cursor-pointer"> 代码

//获取versionName,versionCode
        try {
            PackageManager pm = context.getPackageManager();
            PackageInfo pi = pm.getPackageInfo(context.getPackageName(), PackageManager.GET_ACTIVITIES);
            if (pi != null) {
                int versionCode = pi.versionCode;
            }
        } catch (PackageManager.NameNotFoundException e) {
//            log.error("an error occured when collect package info", e);
        }

该问题已被官方收录

编译时出现Failed to Open zip file

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1

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 图片

class="cursor-pointer"> 文本

该问题已被官方收录

调用scrollToPositionWithOffSet不起作用

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1

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 截图

class="cursor-pointer"> 代码

chatAdapter.addItem(msg);

linearLayoutManager.scrollToPositionWithOffset(chatAdapter.getItemCount() - 1, 0);

############################################################################################
public class ChatAdapter extends BaseAdapter<BmobIMMessage> {

    private static final String TAG = "ChatAdapter";

    //普通文本消息
    private final int TYPE_TEXT_SEND = 0;
    private final int TYPE_TEXT_RECEIVER = 1;
    //图片
    private final int TYPE_IMAGE_SEND = 2;
    private final int TYPE_IMAGE_RECEIVER = 3;
    //语音消息
    private final int TYPE_VOICE_SEND = 4;
    private final int TYPE_VOICE_RECEIVER = 5;

    private String currentUid = "";

    //构造
    public ChatAdapter(Context context) {
        super(context);
        try {
            currentUid = BmobUser.getCurrentUser(User.class).getObjectId();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }


    @Override
    @NonNull
    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        switch (viewType) {
            case TYPE_TEXT_SEND:
                View sendTextView = LayoutInflater.from(parent.getContext())
                        .inflate(R.layout.item_chat_right, parent, false);

                //设置item长按事件
                sendTextView.setOnLongClickListener(new View.OnLongClickListener() {
                    @Override
                    public boolean onLongClick(View view) {
                        if (onItemLongClickListener != null) {
                            onItemLongClickListener.onItemLongClick((Integer) view.getTag());
                        }
                        return false;
                    }
                });

                //设置OnCreateContextMenuListener
                sendTextView.setOnCreateContextMenuListener(new View.OnCreateContextMenuListener() {
                    @Override
                    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
                        menu.add(1, 0, 1, "删除");
                    }
                });

                return new SendTextViewHolder(sendTextView);
            case TYPE_TEXT_RECEIVER:
                View receiverTextView = LayoutInflater.from(parent.getContext())
                        .inflate(R.layout.item_chat_left, parent, false);
                return new ReceiverTextViewHolder(receiverTextView);
            case TYPE_IMAGE_SEND:
                View sendImageView = LayoutInflater.from(parent.getContext())
                        .inflate(R.layout.item_chat_image_right, parent, false);

                //设置item长按事件
                sendImageView.setOnLongClickListener(new View.OnLongClickListener() {
                    @Override
                    public boolean onLongClick(View view) {
                        if (onItemLongClickListener != null) {
                            onItemLongClickListener.onItemLongClick((Integer) view.getTag());
                        }
                        return false;
                    }
                });

                //设置OnCreateContextMenuListener
                sendImageView.setOnCreateContextMenuListener(new View.OnCreateContextMenuListener() {
                    @Override
                    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
                        menu.add(1, 0, 1, "删除");
                    }
                });

                return new SendImageViewHolder(sendImageView, onImageClickListener);
            case TYPE_IMAGE_RECEIVER:
                View receiverImageView = LayoutInflater.from(parent.getContext())
                        .inflate(R.layout.item_chat_image_left, parent, false);
                return new ReceiverImageViewHolder(receiverImageView, onImageClickListener);
            default:
                return null;
        }
    }


    @Override
    public void onBindViewHolder(@NonNull RecyclerView.ViewHolder viewHolder, int position) {
        ((BaseMessageViewHolder) viewHolder).bindData(getItemList(), position);
        if (viewHolder instanceof SendTextViewHolder) {
            viewHolder.itemView.setTag(position);
        } else if (viewHolder instanceof ReceiverTextViewHolder) {
            //
        } else if (viewHolder instanceof SendImageViewHolder) {
              viewHolder.itemView.setTag(position);
        } else if (viewHolder instanceof ReceiverImageViewHolder) {
            viewHolder.itemView.setTag(position);
        }
    }


    @Override
    public int getItemViewType(int position) {
        BmobIMMessage msg = getItem(position);
        if (msg.getMsgType().equals(BmobIMMessageType.TEXT.getType())) {
            return msg.getFromId().equals(currentUid) ? TYPE_TEXT_SEND : TYPE_TEXT_RECEIVER;
        } else if (msg.getMsgType().equals(BmobIMMessageType.IMAGE.getType())) {
            return msg.getFromId().equals(currentUid) ? TYPE_IMAGE_SEND : TYPE_IMAGE_RECEIVER;
        } else if (msg.getMsgType().equals(BmobIMMessageType.VOICE.getType())) {
            return msg.getFromId().equals(currentUid) ? TYPE_VOICE_SEND : TYPE_VOICE_RECEIVER;
        } else {
            return -1;
        }
    }

    public OnImageClickListener onImageClickListener;
    //点击item事件接口
    public interface OnImageClickListener {
        void onImageClick(int position);
    }

    //点击item事件监听
    public void setOnImageClickListener(OnImageClickListener onImageClickListener) {
        this.onImageClickListener = onImageClickListener;
    }
}

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