本帖最後由 ℡_莫忘ヽ悇溫╭ 於 2015-3-24 11:49 編輯 一、 精確獲取屏幕尺寸(例如:3.五、4.0、5.0寸屏幕)
- public static double getScreenPhysicalSize(Activity ctx) {
- DisplayMetrics dm = new DisplayMetrics();
- ctx.getWindowManager().getDefaultDisplay().getMetrics(dm);
- double diagonalPixels = Math.sqrt(Math.pow(dm.widthPixels, 2) + Math.pow(dm.heightPixels, 2));
- return diagonalPixels / (160 * dm.density);
- }
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通常是7寸以上是平板 二、 判斷是不是平板(官方用法)
- public static boolean isTablet(Context context) {
- return (context.getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) >= Configuration.SCREENLAYOUT_SIZE_LARGE;
- }
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三、 文字根據狀態更改顏色 android:textColor
- <selector xmlns:android="http://schemas.android.com/apk/res/android">
- <item android:color="#53c1bd" android:state_selected="true"/>
- <item android:color="#53c1bd" android:state_focused="true"/>
- <item android:color="#53c1bd" android:state_pressed="true"/>
- <item android:color="#777777"/>
- </selector>
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放在res/color/目錄下 四、背景色根據狀態更改顏色 android:backgroup
- <selector xmlns:android="http://schemas.android.com/apk/res/android">
-
- <item android:state_selected="true"><shape> <gradient android:angle="0" android:centerColor="#00a59f" android:endColor="#00a59f" android:startColor="#00a59f" />
- </shape></item>
- <item android:state_focused="true"><shape>
- <gradient android:angle="0" android:centerColor="#00a59f" android:endColor="#00a59f" android:startColor="#00a59f" />
- </shape></item>
- <item android:state_pressed="true"><shape>
- <gradient android:angle="0" android:centerColor="#00a59f" android:endColor="#00a59f" android:startColor="#00a59f" />
- </shape></item>
- <item><shape>
- <gradient android:angle="0" android:centerColor="#00ff00" android:endColor="00ff00" android:startColor="00ff00" />
- </shape></item>
-
- </selector>
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若是直接給背景色color會報錯。 五、 啓動APK的默認Activity
- public static void startApkActivity(final Context ctx, String packageName) {
- PackageManager pm = ctx.getPackageManager();
- PackageInfo pi;
- try {
- pi = pm.getPackageInfo(packageName, 0);
- Intent intent = new Intent(Intent.ACTION_MAIN, null);
- intent.addCategory(Intent.CATEGORY_LAUNCHER);
- intent.setPackage(pi.packageName);
-
- List<ResolveInfo> apps = pm.queryIntentActivities(intent, 0);
-
- ResolveInfo ri = apps.iterator().next();
- if (ri != null) {
- String className = ri.activityInfo.name;
- intent.setComponent(new ComponentName(packageName, className));
- ctx.startActivity(intent);
- }
- } catch (NameNotFoundException e) {
- Log.e("startActivity", e);
- }
- }
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七、計算字寬
- public static float GetTextWidth(String text, float Size) {
- TextPaint FontPaint = new TextPaint();
- FontPaint.setTextSize(Size);
- return FontPaint.measureText(text);
- }
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注意若是設置了textStyle,還須要進一步設置TextPaint。 八、獲取應用程序下全部Activity
- public static ArrayList<String> getActivities(Context ctx) {
- ArrayList<String> result = new ArrayList<String>();
- Intent intent = new Intent(Intent.ACTION_MAIN, null);
- intent.setPackage(ctx.getPackageName());
- for (ResolveInfo info : ctx.getPackageManager().queryIntentActivities(intent, 0)) {
- result.add(info.activityInfo.name);
- }
- return result;
- }
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9、檢測字符串中是否包含漢字
- public static boolean checkChinese(String sequence) {
- final String format = "[\\u4E00-\\u9FA5\\uF900-\\uFA2D]";
- boolean result = false;
- Pattern pattern = Pattern.compile(format);
- Matcher matcher = pattern.matcher(sequence);
- result = matcher.find();
- return result;
- }
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10、檢測字符串中只能包含:中文、數字、下劃線(_)、橫線(-)
- public static boolean checkNickname(String sequence) {
- final String format = "[^\\u4E00-\\u9FA5\\uF900-\\uFA2D\\w-_]";
- Pattern pattern = Pattern.compile(format);
- Matcher matcher = pattern.matcher(sequence);
- return !matcher.find();
- }
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十一、檢查有沒有應用程序來接受處理你發出的intent
- public static boolean isIntentAvailable(Context context, String action) {
- final PackageManager packageManager = context.getPackageManager();
- final Intent intent = new Intent(action);
- List<ResolveInfo> list = packageManager.queryIntentActivities(intent, PackageManager.MATCH_DEFAULT_ONLY);
- return list.size() > 0;
- }
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十二、使用TransitionDrawable實現漸變效果
- private void setImageBitmap(ImageView imageView, Bitmap bitmap) {
- // Use TransitionDrawable to fade in.
- final TransitionDrawable td = new TransitionDrawable(new Drawable[] { new ColorDrawable(android.R.color.transparent), new BitmapDrawable(mContext.getResources(), bitmap) });
- //noinspection deprecation
- imageView.setBackgroundDrawable(imageView.getDrawable());
- imageView.setImageDrawable(td);
- td.startTransition(200);
- }
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比使用AlphaAnimation效果要好,可避免出現閃爍問題。 1三、掃描指定的文件 sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, uri)); 用途:從本軟件新增、修改、刪除圖片、文件某一個文件(音頻、視頻)須要更新系統媒體庫時使用,沒必要掃描整個SD卡 1四、Dip轉px
- public static int dipToPX(final Context ctx, float dip) {
- return (int)TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dip, ctx.getResources().getDisplayMetrics());
- }
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用途:不免在Activity代碼中設置位置、大小等,本方法就頗有用了! 1五、獲取已經安裝APK的路徑
- PackageManager pm = getPackageManager();
-
- for (ApplicationInfo app : pm.getInstalledApplications(0)) {
- Log.d("PackageList", "package: " + app.packageName + ", sourceDir: " + app.sourceDir);
- }
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輸出以下:
- package: com.tmobile.thememanager, sourceDir: /system/app/ThemeManager.apk
- package: com.touchtype.swiftkey, sourceDir: /data/app/com.touchtype.swiftkey-1.apk
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- public static void putStringProcess(Context ctx, String key, String value) {
- SharedPreferences sharedPreferences = ctx.getSharedPreferences("preference_mu", Context.MODE_MULTI_PROCESS);
- Editor editor = sharedPreferences.edit();
- editor.putString(key, value);
- editor.commit();
- }
-
- public static String getStringProcess(Context ctx, String key, String defValue) {
- SharedPreferences sharedPreferences = ctx.getSharedPreferences("preference_mu", Context.MODE_MULTI_PROCESS);
- return sharedPreferences.getString(key, defValue);
- }
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相關文章: php http://zengrong.net/post/1687.htm java 1七、泛型ArrayList轉數組 android
- @SuppressWarnings("unchecked")
- public static <T> T[] toArray(Class<?> cls, ArrayList<T> items) {
- if (items == null || items.size() == 0) {
- return (T[]) Array.newInstance(cls, 0);
- }
- return items.toArray((T[]) Array.newInstance(cls, items.size()));
- }
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1八、保存恢復ListView當前位置 數據庫
- private void saveCurrentPosition() {
- if (mListView != null) {
- int position = mListView.getFirstVisiblePosition();
- View v = mListView.getChildAt(0);
- int top = (v == null) ? 0 : v.getTop();
- //保存position和top
- }
- }
-
- private void restorePosition() {
- if (mFolder != null && mListView != null) {
- int position = 0;//取出保存的數據
- int top = 0;//取出保存的數據
- mListView.setSelectionFromTop(position, top);
- }
- }
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能夠保存在Preference中或者是數據庫中,數據加載完後再設置。 swift 1九、調用 便攜式熱點和數據共享 設置 數組
- public static Intent getHotspotSetting() {
- Intent intent = new Intent();
- intent.setAction(Intent.ACTION_MAIN);
- ComponentName com = new ComponentName("com.android.settings", "com.android.settings.TetherSettings");
- intent.setComponent(com);
- return intent;
- }
-
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20、格式化輸出IP地址 網絡
- public static String getIp(Context ctx) {
- return Formatter.formatIpAddress((WifiManager) ctx.getSystemService(Context.WIFI_SERVICE).getConnectionInfo().getIpAddress());
- }
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2一、文件夾排序(先文件夾排序,後文件排序) app
- public static void sortFiles(File[] files) {
- Arrays.sort(files, new Comparator<File>() {
-
- @Override
- public int compare(File lhs, File rhs) {
- //返回負數表示o1 小於o2,返回0 表示o1和o2相等,返回正數表示o1大於o2。
- boolean l1 = lhs.isDirectory();
- boolean l2 = rhs.isDirectory();
- if (l1 && !l2)
- return -1;
- else if (!l1 && l2)
- return 1;
- else {
- return lhs.getName().compareTo(rhs.getName());
- }
- }
- });
- }
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2二、發送不重複的通知(Notification) ide
- public static void sendNotification(Context context, String title,
- String message, Bundle extras) {
- Intent mIntent = new Intent(context, FragmentTabsActivity.class);
- mIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
- mIntent.putExtras(extras);
-
- int requestCode = (int) System.currentTimeMillis();
-
- PendingIntent mContentIntent = PendingIntent.getActivity(context,
- requestCode, mIntent, 0);
-
- Notification mNotification = new NotificationCompat.Builder(context)
- .setContentTitle(title).setSmallIcon(R.drawable.app_icon)
- .setContentIntent(mContentIntent).setContentText(message)
- .build();
- mNotification.flags |= Notification.FLAG_AUTO_CANCEL;
- mNotification.defaults = Notification.DEFAULT_ALL;
-
- NotificationManager mNotificationManager = (NotificationManager) context
- .getSystemService(Context.NOTIFICATION_SERVICE);
-
- mNotificationManager.notify(requestCode, mNotification);
- }
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關鍵點在這個requestCode,這裏使用的是當前系統時間,巧妙的保證了每次都是一個新的Notification產生。 post 2三、代碼設置TextView的樣式 使用過自定義Dialog可能立刻會想到用以下代碼: new TextView(this,null,R.style.text_style); 但你運行這代碼你會發現毫無做用!正確用法: new TextView(new ContextThemeWrapper(this, R.style.text_style)) 2四、ip地址轉成8位十六進制串
- /** ip轉16進制 */
- public static String ipToHex(String ips) {
- StringBuffer result = new StringBuffer();
- if (ips != null) {
- StringTokenizer st = new StringTokenizer(ips, ".");
- while (st.hasMoreTokens()) {
- String token = Integer.toHexString(Integer.parseInt(st.nextToken()));
- if (token.length() == 1)
- token = "0" + token;
- result.append(token);
- }
- }
- return result.toString();
- }
-
- /** 16進制轉ip */
- public static String texToIp(String ips) {
- try {
- StringBuffer result = new StringBuffer();
- if (ips != null && ips.length() == 8) {
- for (int i = 0; i < 8; i += 2) {
- if (i != 0)
- result.append('.');
- result.append(Integer.parseInt(ips.substring(i, i + 2), 16));
- }
- }
- return result.toString();
- } catch (NumberFormatException ex) {
- Logger.e(ex);
- }
- return "";
- }
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ip:192.168.68.128 16 =>hex :c0a84480 2五、WebView保留縮放功能但隱藏縮放控件
- mWebView.getSettings().setSupportZoom(true);
- mWebView.getSettings().setBuiltInZoomControls(true);
- if (DeviceUtils.hasHoneycomb())
- mWebView.getSettings().setDisplayZoomControls(false);
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注意:setDisplayZoomControls是在API Level 11中新增。 2六、獲取網絡類型名稱
- public static String getNetworkTypeName(Context context) {
- if (context != null) {
- ConnectivityManager connectMgr = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
- if (connectMgr != null) {
- NetworkInfo info = connectMgr.getActiveNetworkInfo();
- if (info != null) {
- switch (info.getType()) {
- case ConnectivityManager.TYPE_WIFI:
- return "WIFI";
- case ConnectivityManager.TYPE_MOBILE:
- return getNetworkTypeName(info.getSubtype());
- }
- }
- }
- }
- return getNetworkTypeName(TelephonyManager.NETWORK_TYPE_UNKNOWN);
- }
-
- public static String getNetworkTypeName(int type) {
- switch (type) {
- case TelephonyManager.NETWORK_TYPE_GPRS:
- return "GPRS";
- case TelephonyManager.NETWORK_TYPE_EDGE:
- return "EDGE";
- case TelephonyManager.NETWORK_TYPE_UMTS:
- return "UMTS";
- case TelephonyManager.NETWORK_TYPE_HSDPA:
- return "HSDPA";
- case TelephonyManager.NETWORK_TYPE_HSUPA:
- return "HSUPA";
- case TelephonyManager.NETWORK_TYPE_HSPA:
- return "HSPA";
- case TelephonyManager.NETWORK_TYPE_CDMA:
- return "CDMA";
- case TelephonyManager.NETWORK_TYPE_EVDO_0:
- return "CDMA - EvDo rev. 0";
- case TelephonyManager.NETWORK_TYPE_EVDO_A:
- return "CDMA - EvDo rev. A";
- case TelephonyManager.NETWORK_TYPE_EVDO_B:
- return "CDMA - EvDo rev. B";
- case TelephonyManager.NETWORK_TYPE_1xRTT:
- return "CDMA - 1xRTT";
- case TelephonyManager.NETWORK_TYPE_LTE:
- return "LTE";
- case TelephonyManager.NETWORK_TYPE_EHRPD:
- return "CDMA - eHRPD";
- case TelephonyManager.NETWORK_TYPE_IDEN:
- return "iDEN";
- case TelephonyManager.NETWORK_TYPE_HSPAP:
- return "HSPA+";
- default:
- return "UNKNOWN";
- }
- }
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2七、Android解壓Zip包
- /**
- * 解壓一個壓縮文檔 到指定位置
- *
- * @param zipFileString 壓縮包的名字
- * @param outPathString 指定的路徑
- * [url=home.php?mod=space&uid=2643633]@throws[/url] Exception
- */
- public static void UnZipFolder(String zipFileString, String outPathString) throws Exception {
- java.util.zip.ZipInputStream inZip = new java.util.zip.ZipInputStream(new java.io.FileInputStream(zipFileString));
- java.util.zip.ZipEntry zipEntry;
- String szName = "";
-
- while ((zipEntry = inZip.getNextEntry()) != null) {
- szName = zipEntry.getName();
-
- if (zipEntry.isDirectory()) {
-
- // get the folder name of the widget
- szName = szName.substring(0, szName.length() - 1);
- java.io.File folder = new java.io.File(outPathString + java.io.File.separator + szName);
- folder.mkdirs();
-
- } else {
-
- java.io.File file = new java.io.File(outPathString + java.io.File.separator + szName);
- file.createNewFile();
- // get the output stream of the file
- java.io.FileOutputStream out = new java.io.FileOutputStream(file);
- int len;
- byte[] buffer = new byte[1024];
- // read (len) bytes into buffer
- while ((len = inZip.read(buffer)) != -1) {
- // write (len) byte from buffer at the position 0
- out.write(buffer, 0, len);
- out.flush();
- }
- out.close();
- }
- }//end of while
-
- inZip.close();
-
- }//end of func
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2八、從assets中讀取文本和圖片資源
- /** 從assets 文件夾中讀取文本數據 */
- public static String getTextFromAssets(final Context context, String fileName) {
- String result = "";
- try {
- InputStream in = context.getResources().getAssets().open(fileName);
- // 獲取文件的字節數
- int lenght = in.available();
- // 建立byte數組
- byte[] buffer = new byte[lenght];
- // 將文件中的數據讀到byte數組中
- in.read(buffer);
- result = EncodingUtils.getString(buffer, "UTF-8");
- in.close();
- } catch (Exception e) {
- e.printStackTrace();
- }
- return result;
- }
-
- /** 從assets 文件夾中讀取圖片 */
- public static Drawable loadImageFromAsserts(final Context ctx, String fileName) {
- try {
- InputStream is = ctx.getResources().getAssets().open(fileName);
- return Drawable.createFromStream(is, null);
- } catch (IOException e) {
- if (e != null) {
- e.printStackTrace();
- }
- } catch (OutOfMemoryError e) {
- if (e != null) {
- e.printStackTrace();
- }
- } catch (Exception e) {
- if (e != null) {
- e.printStackTrace();
- }
- }
- return null;
- }
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2九、展開、收起狀態欄
- public static final void collapseStatusBar(Context ctx) {
- Object sbservice = ctx.getSystemService("statusbar");
- try {
- Class<?> statusBarManager = Class.forName("android.app.StatusBarManager");
- Method collapse;
- if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
- collapse = statusBarManager.getMethod("collapsePanels");
- } else {
- collapse = statusBarManager.getMethod("collapse");
- }
- collapse.invoke(sbservice);
- } catch (Exception e) {
- e.printStackTrace();
- }
- }
-
- public static final void expandStatusBar(Context ctx) {
- Object sbservice = ctx.getSystemService("statusbar");
- try {
- Class<?> statusBarManager = Class.forName("android.app.StatusBarManager");
- Method expand;
- if (Build.VERSION.SDK_INT >= 17) {
- expand = statusBarManager.getMethod("expandNotificationsPanel");
- } else {
- expand = statusBarManager.getMethod("expand");
- }
- expand.invoke(sbservice);
- } catch (Exception e) {
- e.printStackTrace();
- }
- }
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用途:可用於點擊Notifacation以後收起狀態欄 30、獲取狀態欄高度
- public static int getStatusBarHeight(Context context){
- Class<?> c = null;
- Object obj = null;
- Field field = null;
- int x = 0, statusBarHeight = 0;
- try {
- c = Class.forName("com.android.internal.R$dimen");
- obj = c.newInstance();
- field = c.getField("status_bar_height");
- x = Integer.parseInt(field.get(obj).toString());
- statusBarHeight = context.getResources().getDimensionPixelSize(x);
- } catch (Exception e1) {
- e1.printStackTrace();
- }
- return statusBarHeight;
- }
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3一、ListView使用ViewHolder極簡寫法
- public static <T extends View> T getAdapterView(View convertView, int id) {
- SparseArray<View> viewHolder = (SparseArray<View>) convertView.getTag();
- if (viewHolder == null) {
- viewHolder = new SparseArray<View>();
- convertView.setTag(viewHolder);
- }
- View childView = viewHolder.get(id);
- if (childView == null) {
- childView = convertView.findViewById(id);
- viewHolder.put(id, childView);
- }
- return (T) childView;
- }
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用法:
- @Override
- public View getView(int position, View convertView, ViewGroup parent) {
- if (convertView == null) {
- convertView = LayoutInflater.from(getActivity()).inflate(R.layout.fragment_feed_item, parent, false);
- }
-
- ImageView thumnailView = getAdapterView(convertView, R.id.video_thumbnail);
- ImageView avatarView = getAdapterView(convertView, R.id.user_avatar);
- ImageView appIconView = getAdapterView(convertView, R.id.app_icon);
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用起來很是簡練,將ViewHolder隱於無形。 3二、設置Activity透明
- <style name="TransparentActivity" parent="AppBaseTheme">
- <item name="android:windowBackground">@android:color/transparent</item>
- <item name="android:colorBackgroundCacheHint">@null</item>
- <item name="android:windowIsTranslucent">true</item>
- <item name="android:windowNoTitle">true</item>
- <item name="android:windowContentOverlay">@null</item>
- </style>
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說明:AppBaseTheme通常是你application指定的android:theme是啥這裏就是啥,不然Activity內部的空間風格可能不一致。 用途:用於模擬Dialog效果,好比再Service中無法用Dialog,就能夠用Activity來模擬 3三、代碼切換全屏
- //切換到全屏
- getWindow().clearFlags(WindowManager.LayoutParams.FLAG_FORCE_NOT_FULLSCREEN);
- getActivity().getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
-
- //切換到非全屏
- getWindow().clearFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
- getWindow().addFlags(WindowManager.LayoutParams.FLAG_FORCE_NOT_FULLSCREEN);
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注意:切換到全屏時,底部的虛擬按鍵仍然是顯示的。次方法可屢次調用用於切換 用途:播放器界面常常會用到 3四、調用開發者選項中顯示觸摸位置功能 android.provider.Settings.System.putInt(getContentResolver(), "show_touches", 1); 設置1顯示,設置0不顯示。 3五、獲取設備上已安裝而且可啓動的應用列表
- Intent intent = new Intent(Intent.ACTION_MAIN);
- intent.addCategory(Intent.CATEGORY_LAUNCHER);
-
- List<ResolveInfo> activities = getPackageManager().queryIntentActivities(intent, 0)
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注意:使用getInstalledApplications會返回不少沒法啓動甚至沒有圖標的系統應用。ResolveInfo.activityInfo.applicationInfo也能取到你 想要的數據。 |