Android快速开发不可或缺的11个工具类 (一)续篇。
NetUtils是判断网络状态的工具类,在网络时代,开发中绝对的不可或缺。
import android.app.Activity; import android.content.ComponentName; import android.content.Context; import android.content.Intent; import android.net.ConnectivityManager; import android.net.NetworkInfo; //跟网络相关的工具类 public class NetUtils { private NetUtils() { /* cannot be instantiated */ throw new UnsupportedOperationException("cannot be instantiated"); } /** * 判断网络是否连接 * * @param context * @return */ public static boolean isConnected(Context context) { ConnectivityManager connectivity = (ConnectivityManager) context .getSystemService(Context.CONNECTIVITY_SERVICE); if (null != connectivity) { NetworkInfo info = connectivity.getActiveNetworkInfo(); if (null != info && info.isConnected()) { if (info.getState() == NetworkInfo.State.CONNECTED) { return true; } } } return false; } /** * 判断是否是wifi连接 */ public static boolean isWifi(Context context) { ConnectivityManager cm = (ConnectivityManager) context .getSystemService(Context.CONNECTIVITY_SERVICE); if (cm == null) return false; return cm.getActiveNetworkInfo().getType() == ConnectivityManager.TYPE_WIFI; } /** * 打开网络设置界面 */ public static void openSetting(Activity activity) { Intent intent = new Intent("/"); ComponentName cm = new ComponentName("com.android.settings", "com.android.settings.WirelessSettings"); intent.setComponent(cm); intent.setAction("android.intent.action.VIEW"); activity.startActivityForResult(intent, 0); } }
可用于获取屏幕宽高,截屏的工具类
import android.app.Activity; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Rect; import android.util.DisplayMetrics; import android.view.View; import android.view.WindowManager; //获得屏幕相关的辅助类 public class ScreenUtils { private ScreenUtils() { /* cannot be instantiated */ throw new UnsupportedOperationException("cannot be instantiated"); } /** * 获得屏幕高度 * * @param context * @return */ public static int getScreenWidth(Context context) { WindowManager wm = (WindowManager) context .getSystemService(Context.WINDOW_SERVICE); DisplayMetrics outMetrics = new DisplayMetrics(); wm.getDefaultDisplay().getMetrics(outMetrics); return outMetrics.widthPixels; } /** * 获得屏幕宽度 * * @param context * @return */ public static int getScreenHeight(Context context) { WindowManager wm = (WindowManager) context .getSystemService(Context.WINDOW_SERVICE); DisplayMetrics outMetrics = new DisplayMetrics(); wm.getDefaultDisplay().getMetrics(outMetrics); return outMetrics.heightPixels; } /** * 获得状态栏的高度 * * @param context * @return */ public static int getStatusHeight(Context context) { int statusHeight = -1; try { Class<?> clazz = Class.forName("com.android.internal.R$dimen"); Object object = clazz.newInstance(); int height = Integer.parseInt(clazz.getField("status_bar_height") .get(object).toString()); statusHeight = context.getResources().getDimensionPixelSize(height); } catch (Exception e) { e.printStackTrace(); } return statusHeight; } /** * 获取当前屏幕截图,包含状态栏 * * @param activity * @return */ public static Bitmap snapShotWithStatusBar(Activity activity) { View view = activity.getWindow().getDecorView(); view.setDrawingCacheEnabled(true); view.buildDrawingCache(); Bitmap bmp = view.getDrawingCache(); int width = getScreenWidth(activity); int height = getScreenHeight(activity); Bitmap bp = null; bp = Bitmap.createBitmap(bmp, 0, 0, width, height); view.destroyDrawingCache(); return bp; } /** * 获取当前屏幕截图,不包含状态栏 * * @param activity * @return */ public static Bitmap snapShotWithoutStatusBar(Activity activity) { View view = activity.getWindow().getDecorView(); view.setDrawingCacheEnabled(true); view.buildDrawingCache(); Bitmap bmp = view.getDrawingCache(); Rect frame = new Rect(); activity.getWindow().getDecorView().getWindowVisibleDisplayFrame(frame); int statusBarHeight = frame.top; int width = getScreenWidth(activity); int height = getScreenHeight(activity); Bitmap bp = null; bp = Bitmap.createBitmap(bmp, 0, statusBarHeight, width, height - statusBarHeight); view.destroyDrawingCache(); return bp; } }
外部存储相关辅助工具类
import java.io.File; import android.os.Environment; import android.os.StatFs; //SD卡相关的辅助类 public class SDCardUtils { private SDCardUtils() { /* cannot be instantiated */ throw new UnsupportedOperationException("cannot be instantiated"); } /** * 判断SDCard是否可用 * * @return */ public static boolean isSDCardEnable() { return Environment.getExternalStorageState().equals( Environment.MEDIA_MOUNTED); } /** * 获取SD卡路径 * * @return */ public static String getSDCardPath() { return Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator; } /** * 获取SD卡的剩余容量 单位byte * * @return */ public static long getSDCardAllSize() { if (isSDCardEnable()) { StatFs stat = new StatFs(getSDCardPath()); // 获取空闲的数据块的数量 long availableBlocks = (long) stat.getAvailableBlocks() - 4; // 获取单个数据块的大小(byte) long freeBlocks = stat.getAvailableBlocks(); return freeBlocks * availableBlocks; } return 0; } /** * 获取指定路径所在空间的剩余可用容量字节数,单位byte * * @param filePath * @return 容量字节 SDCard可用空间,内部存储可用空间 */ public static long getFreeBytes(String filePath) { // 如果是sd卡的下的路径,则获取sd卡可用容量 if (filePath.startsWith(getSDCardPath())) { filePath = getSDCardPath(); } else {// 如果是内部存储的路径,则获取内存存储的可用容量 filePath = Environment.getDataDirectory().getAbsolutePath(); } StatFs stat = new StatFs(filePath); long availableBlocks = (long) stat.getAvailableBlocks() - 4; return stat.getBlockSize() * availableBlocks; } /** * 获取系统存储路径 * * @return */ public static String getRootDirectoryPath() { return Environment.getRootDirectory().getAbsolutePath(); } }
SharedPreferences工具类,作为存储和获取data下相关文件工具类,对SharedPreferences进行封装,使其使用更简单。
import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.util.Map; import android.content.Context; import android.content.SharedPreferences; public class SPUtils { public SPUtils() { /* cannot be instantiated */ throw new UnsupportedOperationException("cannot be instantiated"); } /** * 保存在手机里面的文件名 */ public static final String FILE_NAME = "share_data"; /** * 保存数据的方法,我们需要拿到保存数据的具体类型,然后根据类型调用不同的保存方法 * * @param context * @param key * @param object */ public static void put(Context context, String key, Object object) { SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE); SharedPreferences.Editor editor = sp.edit(); if (object instanceof String) { editor.putString(key, (String) object); } else if (object instanceof Integer) { editor.putInt(key, (Integer) object); } else if (object instanceof Boolean) { editor.putBoolean(key, (Boolean) object); } else if (object instanceof Float) { editor.putFloat(key, (Float) object); } else if (object instanceof Long) { editor.putLong(key, (Long) object); } else { editor.putString(key, object.toString()); } SharedPreferencesCompat.apply(editor); } /** * 得到保存数据的方法,我们根据默认值得到保存的数据的具体类型,然后调用相对于的方法获取值 * * @param context * @param key * @param defaultObject * @return */ public static Object get(Context context, String key, Object defaultObject) { SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE); if (defaultObject instanceof String) { return sp.getString(key, (String) defaultObject); } else if (defaultObject instanceof Integer) { return sp.getInt(key, (Integer) defaultObject); } else if (defaultObject instanceof Boolean) { return sp.getBoolean(key, (Boolean) defaultObject); } else if (defaultObject instanceof Float) { return sp.getFloat(key, (Float) defaultObject); } else if (defaultObject instanceof Long) { return sp.getLong(key, (Long) defaultObject); } return null; } /** * 移除某个key值已经对应的值 * * @param context * @param key */ public static void remove(Context context, String key) { SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE); SharedPreferences.Editor editor = sp.edit(); editor.remove(key); SharedPreferencesCompat.apply(editor); } /** * 清除所有数据 * * @param context */ public static void clear(Context context) { SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE); SharedPreferences.Editor editor = sp.edit(); editor.clear(); SharedPreferencesCompat.apply(editor); } /** * 查询某个key是否已经存在 * * @param context * @param key * @return */ public static boolean contains(Context context, String key) { SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE); return sp.contains(key); } /** * 返回所有的键值对 * * @param context * @return */ public static Map<String, ?> getAll(Context context) { SharedPreferences sp = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE); return sp.getAll(); } /** * 创建一个解决SharedPreferencesCompat.apply方法的一个兼容类 * * @author zhy * */ private static class SharedPreferencesCompat { private static final Method sApplyMethod = findApplyMethod(); /** * 反射查找apply的方法 * * @return */ @SuppressWarnings({ "unchecked", "rawtypes" }) private static Method findApplyMethod() { try { Class clz = SharedPreferences.Editor.class; return clz.getMethod("apply"); } catch (NoSuchMethodException e) { } return null; } /** * 如果找到则使用apply执行,否则使用commit * * @param editor */ public static void apply(SharedPreferences.Editor editor) { try { if (sApplyMethod != null) { sApplyMethod.invoke(editor); return; } } catch (IllegalArgumentException e) { } catch (IllegalAccessException e) { } catch (InvocationTargetException e) { } editor.commit(); } } }
对系统Toast的封装,用起来更简单方便
import android.content.Context; import android.widget.Toast; //Toast统一管理类 public class ToastUtils { private ToastUtils() { /* cannot be instantiated */ throw new UnsupportedOperationException("cannot be instantiated"); } public static boolean isShow = true; /** * 短时间显示Toast * * @param context * @param message */ public static void showShort(Context context, CharSequence message) { if (isShow) Toast.makeText(context, message, Toast.LENGTH_SHORT).show(); } /** * 短时间显示Toast * * @param context * @param message */ public static void showShort(Context context, int message) { if (isShow) Toast.makeText(context, message, Toast.LENGTH_SHORT).show(); } /** * 长时间显示Toast * * @param context * @param message */ public static void showLong(Context context, CharSequence message) { if (isShow) Toast.makeText(context, message, Toast.LENGTH_LONG).show(); } /** * 长时间显示Toast * * @param context * @param message */ public static void showLong(Context context, int message) { if (isShow) Toast.makeText(context, message, Toast.LENGTH_LONG).show(); } /** * 自定义显示Toast时间 * * @param context * @param message * @param duration */ public static void show(Context context, CharSequence message, int duration) { if (isShow) Toast.makeText(context, message, duration).show(); } /** * 自定义显示Toast时间 * * @param context * @param message * @param duration */ public static void show(Context context, int message, int duration) { if (isShow) Toast.makeText(context, message, duration).show(); } }
今天,Android不可或缺的开发工具类集合的分享就到这里,上篇为Android快速开发不可或缺的11个工具类 (一)。
本文转载自:http://www.devstore.cn/code/info/363.htm。
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