20.Android 设备工具DeviceUtil

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dp转换px

在自定义View中必须用到这个方法。自定义View的时候，不能像在xml那样可以设置dp（密度），只能设置px（像素）。不同分辨率的设备，设置px，显示就不会一样了。为了结合设计图设置dp，需要将dp转换为px值，然后再设置。

    /**     * dp 转化为 px     * @param context     * @param dpValue     * @return     */    public static int dp2px(Context context, float dpValue) {        final float scale = context.getResources().getDisplayMetrics().density;        return (int) (dpValue * scale + 0.5f);    }

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px转换dp

    /**     * px 转化为 dp     * @param context     * @param pxValue     * @return     */    public static int px2dp(Context context, float pxValue) {        final float scale = context.getResources().getDisplayMetrics().density;        return (int) (pxValue / scale + 0.5f);    }

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设备宽度

    /**     * 获取设备宽度（px）     * @param context     * @return     */    public static int deviceWidth(Context context) {        return context.getResources().getDisplayMetrics().widthPixels;    }

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设备高度

    /**     * 获取设备高度（px）     * @param context     * @return     */    public static int deviceHeight(Context context) {        return context.getResources().getDisplayMetrics().heightPixels;    }

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SD卡判断

    /**     * SD卡判断     * @return     */    public static boolean isSDCardAvailable() {        return Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED);    }

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网络判断

    /**     * 是否有网     * @param context     * @return     */    public static boolean isNetworkConnected(Context context) {        if (context != null) {            ConnectivityManager mConnectivityManager = (ConnectivityManager) context                    .getSystemService(Context.CONNECTIVITY_SERVICE);            NetworkInfo mNetworkInfo = mConnectivityManager                    .getActiveNetworkInfo();            if (mNetworkInfo != null) {                return mNetworkInfo.isAvailable();            }        }        return false;    }

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VersionName

对应build.gradle中的versionName

    /**     * 返回版本名字     * 对应build.gradle中的versionName     *     * @param context     * @return     */    public static String getVersionName(Context context) {        String versionName = "";        try {            PackageManager packageManager = context.getPackageManager();            PackageInfo packInfo = packageManager.getPackageInfo(context.getPackageName(), 0);            versionName = packInfo.versionName;        } catch (Exception e) {            e.printStackTrace();        }        return versionName;    }

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VersionCode

对应build.gradle中的versionCode

    /**     * 返回版本号     * 对应build.gradle中的versionCode     *     * @param context     * @return     */    public static String getVersionCode(Context context) {        String versionCode = "";        try {            PackageManager packageManager = context.getPackageManager();            PackageInfo packInfo = packageManager.getPackageInfo(context.getPackageName(), 0);            versionCode = String.valueOf(packInfo.versionCode);        } catch (Exception e) {            e.printStackTrace();        }        return versionCode;    }

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DeviceId

每台设备都有唯一的标识，这就是DeviceId

    /**     * 获取设备的唯一标识，deviceId     *     * @param context     * @return     */    public static String getDeviceId(Context context) {        TelephonyManager tm = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);        String deviceId = tm.getDeviceId();        if (deviceId == null) {            return "-";        } else {            return deviceId;        }    }

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手机品牌

    /**     * 获取手机品牌     *     * @return     */    public static String getPhoneBrand() {        return android.os.Build.BRAND;    }

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手机型号

    /**     * 获取手机型号     *     * @return     */    public static String getPhoneModel() {        return android.os.Build.MODEL;    }

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系统Android API等级

    /**     * 获取手机Android API等级（22、23 ...）     *     * @return     */    public static int getBuildLevel() {        return android.os.Build.VERSION.SDK_INT;    }

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系统Android 版本

   /**     * 获取手机Android 版本（4.4、5.0、5.1 ...）     *     * @return     */    public static String getBuildVersion() {        return android.os.Build.VERSION.RELEASE;    }

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App进程id

    /**     * 获取当前App进程的id     *     * @return     */    public static int getAppProcessId() {        return android.os.Process.myPid();    }

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App进程Name

    /**     * 获取当前App进程的Name     *     * @param context     * @param processId     * @return     */    public static String getAppProcessName(Context context, int processId) {        String processName = null;        ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);        // 获取所有运行App的进程集合        List l = am.getRunningAppProcesses();        Iterator i = l.iterator();        PackageManager pm = context.getPackageManager();        while (i.hasNext()) {            ActivityManager.RunningAppProcessInfo info = (ActivityManager.RunningAppProcessInfo) (i.next());            try {                if (info.pid == processId) {                    CharSequence c = pm.getApplicationLabel(pm.getApplicationInfo(info.processName, PackageManager.GET_META_DATA));                    processName = info.processName;                    return processName;                }            } catch (Exception e) {                Log.e(DeviceUtil.class.getName(), e.getMessage(), e);            }        }        return processName;    }

创建App缓存文件夹

    /**     * 创建App文件夹     *     * @param appName     * @param application     * @return     */    public static String createAPPFolder(String appName, Application application) {        return createAPPFolder(appName, application, null);    }    /**     * 创建App文件夹     *     * @param appName     * @param application     * @param folderName     * @return     */    public static String createAPPFolder(String appName, Application application, String folderName) {        File root = Environment.getExternalStorageDirectory();        File folder;        /**         * 如果存在SD卡         */        if (DeviceUtil.isSDCardAvailable() && root != null) {            folder = new File(root, appName);            if (!folder.exists()) {                folder.mkdirs();            }        } else {            /**             * 不存在SD卡，就放到缓存文件夹内             */            root = application.getCacheDir();            folder = new File(root, appName);            if (!folder.exists()) {                folder.mkdirs();            }        }        if (folderName != null) {            folder = new File(folder, folderName);            if (!folder.exists()) {                folder.mkdirs();            }        }        return folder.getAbsolutePath();    }

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Uri转换File

    /**     * 通过Uri找到File     *     * @param context     * @param uri     * @return     */    public static File uri2File(Activity context, Uri uri) {        File file;        String[] project = {MediaStore.Images.Media.DATA};        Cursor actualImageCursor = context.getContentResolver().query(uri, project, null, null, null);        if (actualImageCursor != null) {            int actual_image_column_index = actualImageCursor                    .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);            actualImageCursor.moveToFirst();            String img_path = actualImageCursor                    .getString(actual_image_column_index);            file = new File(img_path);        } else {            file = new File(uri.getPath());        }        if (actualImageCursor != null) actualImageCursor.close();        return file;    }

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获取AndroidManifest.xml里meta data的值

AndroidManifest.xml

比如自定义了一个meta-data，名为DEBUG。

<meta-data    android:name="DEBUG"    android:value="${DEBUG}" />

build.gradle

然后在build.gradle里给这个DEBUG赋值了。

    //渠道Flavors    productFlavors {        APPTest {            applicationId "com.zyy.camnter.newlife"            manifestPlaceholders = [DEBUG         : "debug"]        }    }

可以通过一下方法取得AndroidManifest.xml里DEBUG被赋上的值：

    /**     * 获取AndroidManifest.xml里 <meta-data>的值     *     * @param context     * @param name     * @return     */    public static String getMetaData(Context context, String name) {        String value = null;        try {            ApplicationInfo appInfo = context.getPackageManager().getApplicationInfo(context.getPackageName(), PackageManager.GET_META_DATA);            value = appInfo.metaData.getString(name);        } catch (PackageManager.NameNotFoundException e) {            e.printStackTrace();        }        return value;    }

DeviceUtil全部源码

public class DeviceUtil {    /**     * dp 转化为 px     *     * @param context     * @param dpValue     * @return     */    public static int dp2px(Context context, float dpValue) {        final float scale = context.getResources().getDisplayMetrics().density;        return (int) (dpValue * scale + 0.5f);    }    /**     * px 转化为 dp     *     * @param context     * @param pxValue     * @return     */    public static int px2dp(Context context, float pxValue) {        final float scale = context.getResources().getDisplayMetrics().density;        return (int) (pxValue / scale + 0.5f);    }    /**     * 获取设备宽度（px）     *     * @param context     * @return     */    public static int deviceWidth(Context context) {        return context.getResources().getDisplayMetrics().widthPixels;    }    /**     * 获取设备高度（px）     *     * @param context     * @return     */    public static int deviceHeight(Context context) {        return context.getResources().getDisplayMetrics().heightPixels;    }    /**     * SD卡判断     *     * @return     */    public static boolean isSDCardAvailable() {        return Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED);    }    /**     * 是否有网     *     * @param context     * @return     */    public static boolean isNetworkConnected(Context context) {        if (context != null) {            ConnectivityManager mConnectivityManager = (ConnectivityManager) context                    .getSystemService(Context.CONNECTIVITY_SERVICE);            NetworkInfo mNetworkInfo = mConnectivityManager                    .getActiveNetworkInfo();            if (mNetworkInfo != null) {                return mNetworkInfo.isAvailable();            }        }        return false;    }    /**     * 返回版本名字     * 对应build.gradle中的versionName     *     * @param context     * @return     */    public static String getVersionName(Context context) {        String versionName = "";        try {            PackageManager packageManager = context.getPackageManager();            PackageInfo packInfo = packageManager.getPackageInfo(context.getPackageName(), 0);            versionName = packInfo.versionName;        } catch (Exception e) {            e.printStackTrace();        }        return versionName;    }    /**     * 返回版本号     * 对应build.gradle中的versionCode     *     * @param context     * @return     */    public static String getVersionCode(Context context) {        String versionCode = "";        try {            PackageManager packageManager = context.getPackageManager();            PackageInfo packInfo = packageManager.getPackageInfo(context.getPackageName(), 0);            versionCode = String.valueOf(packInfo.versionCode);        } catch (Exception e) {            e.printStackTrace();        }        return versionCode;    }    /**     * 获取设备的唯一标识，deviceId     *     * @param context     * @return     */    public static String getDeviceId(Context context) {        TelephonyManager tm = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);        String deviceId = tm.getDeviceId();        if (deviceId == null) {            return "-";        } else {            return deviceId;        }    }    /**     * 获取手机品牌     *     * @return     */    public static String getPhoneBrand() {        return android.os.Build.BRAND;    }    /**     * 获取手机型号     *     * @return     */    public static String getPhoneModel() {        return android.os.Build.MODEL;    }    /**     * 获取手机Android API等级（22、23 ...）     *     * @return     */    public static int getBuildLevel() {        return android.os.Build.VERSION.SDK_INT;    }    /**     * 获取手机Android 版本（4.4、5.0、5.1 ...）     *     * @return     */    public static String getBuildVersion() {        return android.os.Build.VERSION.RELEASE;    }    /**     * 获取当前App进程的id     *     * @return     */    public static int getAppProcessId() {        return android.os.Process.myPid();    }    /**     * 获取当前App进程的Name     *     * @param context     * @param processId     * @return     */    public static String getAppProcessName(Context context, int processId) {        String processName = null;        ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);        // 获取所有运行App的进程集合        List l = am.getRunningAppProcesses();        Iterator i = l.iterator();        PackageManager pm = context.getPackageManager();        while (i.hasNext()) {            ActivityManager.RunningAppProcessInfo info = (ActivityManager.RunningAppProcessInfo) (i.next());            try {                if (info.pid == processId) {                    CharSequence c = pm.getApplicationLabel(pm.getApplicationInfo(info.processName, PackageManager.GET_META_DATA));                    processName = info.processName;                    return processName;                }            } catch (Exception e) {                Log.e(DeviceUtil.class.getName(), e.getMessage(), e);            }        }        return processName;    }    /**     * 创建App文件夹     *     * @param appName     * @param application     * @return     */    public static String createAPPFolder(String appName, Application application) {        return createAPPFolder(appName, application, null);    }    /**     * 创建App文件夹     *     * @param appName     * @param application     * @param folderName     * @return     */    public static String createAPPFolder(String appName, Application application, String folderName) {        File root = Environment.getExternalStorageDirectory();        File folder;        /**         * 如果存在SD卡         */        if (DeviceUtil.isSDCardAvailable() && root != null) {            folder = new File(root, appName);            if (!folder.exists()) {                folder.mkdirs();            }        } else {            /**             * 不存在SD卡，就放到缓存文件夹内             */            root = application.getCacheDir();            folder = new File(root, appName);            if (!folder.exists()) {                folder.mkdirs();            }        }        if (folderName != null) {            folder = new File(folder, folderName);            if (!folder.exists()) {                folder.mkdirs();            }        }        return folder.getAbsolutePath();    }    /**     * 通过Uri找到File     *     * @param context     * @param uri     * @return     */    public static File uri2File(Activity context, Uri uri) {        File file;        String[] project = {MediaStore.Images.Media.DATA};        Cursor actualImageCursor = context.getContentResolver().query(uri, project, null, null, null);        if (actualImageCursor != null) {            int actual_image_column_index = actualImageCursor                    .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);            actualImageCursor.moveToFirst();            String img_path = actualImageCursor                    .getString(actual_image_column_index);            file = new File(img_path);        } else {            file = new File(uri.getPath());        }        if (actualImageCursor != null) actualImageCursor.close();        return file;    }    /**     * 获取AndroidManifest.xml里 <meta-data>的值     *     * @param context     * @param name     * @return     */    public static String getMetaData(Context context, String name) {        String value = null;        try {            ApplicationInfo appInfo = context.getPackageManager().getApplicationInfo(context.getPackageName(), PackageManager.GET_META_DATA);            value = appInfo.metaData.getString(name);        } catch (PackageManager.NameNotFoundException e) {            e.printStackTrace();        }        return value;    }}