Android杂记-EW帮帮网

最近一年在工作上除了后端开发之余还因为大学专业是Android开发，还被安排了开发了两个APP,算是重操旧业了。更新了一波Android的一些技术栈也将一些开发遇到的零零碎碎小问题记录了下来。

获取主题的颜色

android:background="?attr/colorPrimary"

PagerView 嵌套Fragment 中RecyclerView失效的问题

重写了主页面

原本布局

修改后布局

在这里插入图片描述

修改后RecycleView与ViewPager冲突

解决办法

https://juejin.cn/post/6956588617758146573
https://www.jianshu.com/p/a53af20c159a

方法一官方推荐

用下面的NestedScrollableHost作为RecyclerView的容器可以解决滑动冲突，具体代码及注释如下：

//RecyclerView.java

...
//0  
private int mScrollState = SCROLL_STATE_IDLE;
...
@Override
public boolean onInterceptTouchEvent(MotionEvent e) {
   ...
   //1  
   final boolean canScrollHorizontally = mLayout.canScrollHorizontally();
   final boolean canScrollVertically = mLayout.canScrollVertically();
   ...
     
   switch (action) {
       ...
       case MotionEvent.ACTION_MOVE: {
               	...
                final int x = (int) (e.getX(index) + 0.5f);
                final int y = (int) (e.getY(index) + 0.5f);
         				//2
                if (mScrollState != SCROLL_STATE_DRAGGING) {
                    final int dx = x - mInitialTouchX;
                    final int dy = y - mInitialTouchY;
                    boolean startScroll = false;
                  	//2
                    if (canScrollHorizontally && Math.abs(dx) > mTouchSlop) {
                        mLastTouchX = x;
                        startScroll = true;
                    }
                    //3
                    if (canScrollVertically && Math.abs(dy) > mTouchSlop) {
                        mLastTouchY = y;
                        startScroll = true;
                    }
                  	//4
                    if (startScroll) {
                        setScrollState(SCROLL_STATE_DRAGGING);
                    }
                }
            } break;
       ...
   }
   //5
   return mScrollState == SCROLL_STATE_DRAGGING;
}

但似乎由于我ViewPager跟RecycleView中间套了个Fragemnt 使用这个方法闪退

方法二自定义View继承RecyclerView

public class RecyclerViewAtViewPager2 extends RecyclerView {

    public RecyclerViewAtViewPager2(@NonNull Context context) {
        super(context);
    }

    public RecyclerViewAtViewPager2(@NonNull Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    public RecyclerViewAtViewPager2(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    private int startX, startY;

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        switch (ev.getAction()) {
            case MotionEvent.ACTION_DOWN:
                startX = (int) ev.getX();
                startY = (int) ev.getY();
                getParent().requestDisallowInterceptTouchEvent(true);
                break;
            case MotionEvent.ACTION_MOVE:
                int endX = (int) ev.getX();
                int endY = (int) ev.getY();
                int disX = Math.abs(endX - startX);
                int disY = Math.abs(endY - startY);
                LogUtils.debugInfo("DispatchTouchEvent disX="+ disX + "; disY" + disY + "; canScrollHorizontally(startX - endX) = " + canScrollHorizontally(startX - endX) + "; canScrollVertically(startY - endY)" + canScrollVertically(startY - endY));
                if (disX > disY) {
                    //如果是纵向滑动，告知父布局不进行时间拦截，交由子布局消费，　requestDisallowInterceptTouchEvent(true)
                    getParent().requestDisallowInterceptTouchEvent(canScrollHorizontally(startX - endX));
                } else {
                    getParent().requestDisallowInterceptTouchEvent(canScrollVertically(startX - endX));
                }
                break;
            case MotionEvent.ACTION_UP:
            case MotionEvent.ACTION_CANCEL:
                getParent().requestDisallowInterceptTouchEvent(false);
                break;
        }
        return super.dispatchTouchEvent(ev);
    }
}

获取所有的已安装App列表

添加权限

<uses-permission android:name="android.permission.QUERY_ALL_PACKAGES" tools:ignore="QueryAllPackagesPermission" />

获取已经安装的所有应用，PackageInfo系统类，包含应用信息

private void getPackages() {
    // 获取已经安装的所有应用，PackageInfo系统类，包含应用信息
    List<PackageInfo> packages = getPackageManager().getInstalledPackages(0);
    for (int i = 0; i < packages.size(); i++) {
        PackageInfo packageInfo = packages.get(i);
        if ((packageInfo.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) == 0) { //非系统用
            // AppInfo自定义类，包含应用信息
            AppInfo appInfo = new AppInfo();
            appInfo.setAppName(packageInfo.applicationInfo.loadLabel(getPackageManager()).toString()); //获取应用名称
            appInfo.setPackageName(packageInfo.packageName); //获取应用包名，可用于卸载和启动应用
            appInfo.setVersionName(packageInfo.versionName); //获取应用版本名
            appInfo.setVersionCode(packageInfo.versionCode); //获取应用版本号
            appInfo.setAppIcon(packageInfo.applicationInfo.loadIcon(getPackageManager())); //获取应用图标
        } else { // 系统应用
            
        }
    }
}

获取所有用户已安装APP并且读取ClassName

private List<ResolveInfo> getAppInfos() {
    Intent intent = new Intent(Intent.ACTION_MAIN);
    intent.addCategory(Intent.CATEGORY_LAUNCHER);
    return getPackageManager().queryIntentActivities(intent, 0);
}

List<ResolveInfo> packages = getAppInfos();

String packName = packages.get(position).activityInfo.packageName;
String className = packages.get(position).activityInfo.name;

默认横屏

在AndroidManifest.xml文件的activity内添加android:screenOrientation="landscape"

<activity
    android:name=".MainActivity"
    android:screenOrientation="landscape">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

界面被输入法挤压

在AndroidManifest.xml文件中增加android:windowSoftInputMode="adjustNothing"，生效后界面不会被挤压。常用的值是adjustPan。

<activity
    android:name=".MainActivity"
    android:windowSoftInputMode="adjustNothing">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

隐藏虚拟按键

/**
* 隐藏虚拟按键，并且全屏
*/
protected void hideBottomUI() {
    int uiFlags = View.SYSTEM_UI_FLAG_LAYOUT_STABLE
        | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
        | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
        | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
        | View.SYSTEM_UI_FLAG_FULLSCREEN;

    if (android.os.Build.VERSION.SDK_INT >= 19) {
        uiFlags |= View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY;
    } else {
        uiFlags |= View.SYSTEM_UI_FLAG_LOW_PROFILE;
    }
    getWindow().getDecorView().setSystemUiVisibility(uiFlags);
    //解决虚拟按键弹出，无法再次隐藏的问题
    getWindow().getDecorView().setOnSystemUiVisibilityChangeListener((i) -> hideBottomUI());
}

/**
* 隐藏虚拟按键，并且全屏
*/
protected void hideBottomUIMenu() {
    //隐藏虚拟按键，并且全屏
    if (Build.VERSION.SDK_INT > 11 && Build.VERSION.SDK_INT < 19) { // lower api
        View v = this.getWindow().getDecorView();
        v.setSystemUiVisibility(View.GONE);
    } else if (Build.VERSION.SDK_INT >= 19) {
        Window _window = getWindow();
        WindowManager.LayoutParams params = _window.getAttributes();
        params.systemUiVisibility = View.SYSTEM_UI_FLAG_HIDE_NAVIGATION|View.SYSTEM_UI_FLAG_IMMERSIVE;
        _window.setAttributes(params);
    }
}

卸载系统签名应用

安装了系统证书签名的APP并且使用了android:sharedUserId="android.uid.system"时会出现报错INSTALL_FAILED_SHARED_USER_INCOMPATIBLE

使用adb命令卸载

adb uninstall com.XXX.XXX

json 转实体多重嵌套会转成Link

子类也需要添加注释

- @SerializedName
- @Expose

获取唯一设备ID

package com.lnt.lnt_skillappraisal_android.utils;

import android.annotation.SuppressLint;
import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.content.SharedPreferences;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.provider.MediaStore;
import android.telephony.TelephonyManager;
import android.text.TextUtils;
import android.util.Log;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.util.UUID;

public final class DeviceIdUtils {
    private static final String TAG = DeviceIdUtils.class.getSimpleName();

    private static final String TEMP_DIR = "system_config";
    private static final String TEMP_FILE_NAME = "system_file";
    private static final String TEMP_FILE_NAME_MIME_TYPE = "application/octet-stream";
    private static final String SP_NAME = "device_info";
    private static final String SP_KEY_DEVICE_ID = "device_id";

    public static String getDeviceId(Context context) {
        SharedPreferences sharedPreferences = context.getSharedPreferences(SP_NAME, Context.MODE_PRIVATE);
        String deviceId = sharedPreferences.getString(SP_KEY_DEVICE_ID, null);
        if (!TextUtils.isEmpty(deviceId)) {
            return deviceId;
        }
        deviceId = getIMEI(context);
        if (TextUtils.isEmpty(deviceId)) {
            deviceId = createUUID(context);
        }
        sharedPreferences.edit()
                .putString(SP_KEY_DEVICE_ID, deviceId)
                .apply();
        return deviceId;
    }

    private static String createUUID(Context context) {
        String uuid = UUID.randomUUID().toString().replace("-", "");

        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.Q) {
            Uri externalContentUri = MediaStore.Downloads.EXTERNAL_CONTENT_URI;
            ContentResolver contentResolver = context.getContentResolver();
            String[] projection = new String[]{
                    MediaStore.Downloads._ID
            };
            String selection = MediaStore.Downloads.TITLE + "=?";
            String[] args = new String[]{
                    TEMP_FILE_NAME
            };
            Cursor query = contentResolver.query(externalContentUri, projection, selection, args, null);
            if (query != null && query.moveToFirst()) {
                Uri uri = ContentUris.withAppendedId(externalContentUri, query.getLong(0));
                query.close();

                InputStream inputStream = null;
                BufferedReader bufferedReader = null;
                try {
                    inputStream = contentResolver.openInputStream(uri);
                    if (inputStream != null) {
                        bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
                        uuid = bufferedReader.readLine();
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                } finally {
                    if (bufferedReader != null) {
                        try {
                            bufferedReader.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                    if (inputStream != null) {
                        try {
                            inputStream.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
            } else {
                ContentValues contentValues = new ContentValues();
                contentValues.put(MediaStore.Downloads.TITLE, TEMP_FILE_NAME);
                contentValues.put(MediaStore.Downloads.MIME_TYPE, TEMP_FILE_NAME_MIME_TYPE);
                contentValues.put(MediaStore.Downloads.DISPLAY_NAME, TEMP_FILE_NAME);
                contentValues.put(MediaStore.Downloads.RELATIVE_PATH, Environment.DIRECTORY_DOWNLOADS + File.separator + TEMP_DIR);

                Uri insert = contentResolver.insert(externalContentUri, contentValues);
                if (insert != null) {
                    OutputStream outputStream = null;
                    try {
                        outputStream = contentResolver.openOutputStream(insert);
                        if (outputStream == null) {
                            return uuid;
                        }
                        outputStream.write(uuid.getBytes());
                    } catch (IOException e) {
                        e.printStackTrace();
                    } finally {
                        if (outputStream != null) {
                            try {
                                outputStream.close();
                            } catch (IOException e) {
                                e.printStackTrace();
                            }
                        }
                    }
                }
            }
        } else {
            File externalDownloadsDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
            File applicationFileDir = new File(externalDownloadsDir, TEMP_DIR);
            if (!applicationFileDir.exists()) {
                if (!applicationFileDir.mkdirs()) {
                    Log.e(TAG, "文件夹创建失败: " + applicationFileDir.getPath());
                }
            }
            File file = new File(applicationFileDir, TEMP_FILE_NAME);
            if (!file.exists()) {
                FileWriter fileWriter = null;
                try {
                    if (file.createNewFile()) {
                        fileWriter = new FileWriter(file, false);
                        fileWriter.write(uuid);
                    } else {
                        Log.e(TAG, "文件创建失败：" + file.getPath());
                    }
                } catch (IOException e) {
                    Log.e(TAG, "文件创建失败：" + file.getPath());
                    e.printStackTrace();
                } finally {
                    if (fileWriter != null) {
                        try {
                            fileWriter.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
            } else {
                FileReader fileReader = null;
                BufferedReader bufferedReader = null;
                try {
                    fileReader = new FileReader(file);
                    bufferedReader = new BufferedReader(fileReader);
                    uuid = bufferedReader.readLine();

                    bufferedReader.close();
                    fileReader.close();
                } catch (IOException e) {
                    e.printStackTrace();
                } finally {
                    if (bufferedReader != null) {
                        try {
                            bufferedReader.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }

                    if (fileReader != null) {
                        try {
                            fileReader.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
            }
        }

        return uuid;
    }

    private static String getIMEI(Context context) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
            return null;
        }
        try {
            TelephonyManager telephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
            if (telephonyManager == null) {
                return null;
            }
            @SuppressLint({"MissingPermission", "HardwareIds"}) String imei = telephonyManager.getDeviceId();
            return imei;
        } catch (Exception e) {
            return null;
        }
    }
}

灰白模式

public class StudyApp extends Application {
 
    @Override
    public void onCreate() {
        super.onCreate();
 
        Paint mPaint = new Paint();
        ColorMatrix mColorMatrix = new ColorMatrix();
        mColorMatrix.setSaturation(0);
        mPaint.setColorFilter(new ColorMatrixColorFilter(mColorMatrix));
 
        registerActivityLifecycleCallbacks(new ActivityLifecycleCallbacks() {
 
            @Override
            public void onActivityCreated(@NonNull Activity activity, @Nullable Bundle savedInstanceState) {
                // 当Activity创建，我们拿到DecorView，使用Paint进行重绘
                View decorView = activity.getWindow().getDecorView();
                decorView.setLayerType(View.LAYER_TYPE_HARDWARE, mPaint);
            }
 
            ....
        });
    }
}

Android检测NFC卡被拦截

AndroidManifest.xml新增intent-filter

<intent-filter>
    <action android:name="android.nfc.action.NDEF_DISCOVERED"/>
    <category android:name="android.intent.category.DEFAULT"/>
    <data android:mimeType="text/plain" />
</intent-filter>

实现自定义消息声音

需要权限

    <!-- 读取存储空间的权限 -->
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

    <!-- 设置铃声的权限 -->
    <uses-permission android:name="android.permission.WRITE_SETTINGS" />

可以使用以下代码来发送通知

    private void sendNotification(Context context) {
        Intent intent = new Intent(context, MainActivity.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        if(pushContentModel.getUni()!=null){
            intent.putExtra("uni",pushContentModel.getUni());
        }
        PendingIntent pendingIntent = PendingIntent.getActivity(context, 0 /* Request code */, intent,
                PendingIntent.FLAG_ONE_SHOT);

        String channelId = "my_channel_01";
        String channelName = "my_channel";
        // 设置自定义铃声
        String soundUri = ContentResolver.SCHEME_ANDROID_RESOURCE + "://" + context.getPackageName() + "/" + R.raw.custom_notification_sound;
        NotificationManager notificationManager = (NotificationManager) context.getSystemService(context.NOTIFICATION_SERVICE);
        // 创建通知渠道
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            AudioAttributes audioAttributes = new AudioAttributes.Builder()
                    .setUsage(AudioAttributes.USAGE_NOTIFICATION)
                    .setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION)
                    .build();

            NotificationChannel notificationChannel = new NotificationChannel(channelId, channelName, NotificationManager.IMPORTANCE_HIGH);
            notificationChannel.setDescription("channelDescription");
            notificationChannel.enableLights(true);
            notificationChannel.enableVibration(true);
            notificationChannel.setSound(Uri.parse(soundUri), audioAttributes);
            notificationManager.createNotificationChannel(notificationChannel);
        }
        // 构建通知
        NotificationCompat.Builder builder = new NotificationCompat.Builder(context, channelId)
                .setSmallIcon(R.mipmap.logo)
                .setContentTitle(pushContentModel.getTitle())
                .setContentText(pushContentModel.getContent())
                .setPriority(NotificationCompat.PRIORITY_HIGH)
                .setContentIntent(pendingIntent)
                .setAutoCancel(true);

        notificationManager.notify(notificationId, builder.build());

    }

EditText居右显示文本

android:textAlignment="textEnd"

安装更新APP

在您的 AndroidManifest.xml 文件中，检查 FileProvider 的声明：

<manifest>
    <!-- ... -->
    <application>
        <!-- ... -->
        <provider
            android:name="androidx.core.content.FileProvider"
            android:authorities="com.your.package.name.fileprovider"
            android:exported="false"
            android:grantUriPermissions="true">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/file_paths" />
        </provider>
    </application>
</manifest>

在 res/xml 文件夹下的 file_paths.xml 文件中，确保正确配置根目录和文件路径：

<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <files-path
        name="files-path"
        path="." />
    <cache-path
        name="cache-path"
        path="." />
    <external-files-path
        name="external_files"
        path="." />
    <external-cache-path
        name="external_cache"
        path="." />
    <external-path
        name="external_storage_root"
        path="." />
    <root-path
        name="my_image" path="."/>
</paths>

在Activity中调用

Intent intent = new Intent(Intent.ACTION_VIEW);
Uri apkUri = FileProvider.getUriForFile(getContext(), "com.sc.workstation.fileprovider", file);
intent.setData(apkUri);
intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
startActivity(intent);

Android杂记

获取主题的颜色

PagerView 嵌套Fragment 中RecyclerView失效的问题

重写了主页面

原本布局

修改后布局

解决办法

方法一官方推荐

方法二自定义View继承RecyclerView

获取所有的已安装App列表

默认横屏

界面被输入法挤压

隐藏虚拟按键

卸载系统签名应用

json 转实体多重嵌套会转成Link

获取唯一设备ID

灰白模式

Android检测NFC卡被拦截

实现自定义消息声音

需要权限

可以使用以下代码来发送通知

EditText居右显示文本

安装更新APP

网站公告

今日签到

热门文章

最新发布

Android杂记

获取主题的颜色

PagerView 嵌套Fragment 中RecyclerView失效的问题

重写了主页面

原本布局

修改后布局

解决办法

方法一 官方推荐

方法二 自定义View继承RecyclerView

获取所有的已安装App列表

默认横屏

界面被输入法挤压

隐藏虚拟按键

卸载系统签名应用

json 转实体多重嵌套会转成Link

获取唯一设备ID

灰白模式

Android检测NFC卡被拦截

实现自定义消息声音

需要权限

可以使用以下代码来发送通知

EditText居右显示文本

安装更新APP

网站公告

今日签到

热门文章

最新发布

方法一官方推荐

方法二自定义View继承RecyclerView