一、获取应用程序下所有Activity
public static ArrayList getActivities(Context ctx) {
ArrayList result = new ArrayList();
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;
}
二、检测字符串中是否包含汉字
public static boolean checkChinese(String sequence) {
boolean result = false;
Pattern pattern = Pattern.compile(format);
Matcher matcher = pattern.matcher(sequence);
result = matcher.find();
return result;
}
三、检测字符串中只能包含：中文、数字、下划线(_)、横线(-)
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();
}
四、使用TransitionDrawable实现渐变效果
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);
}
比使用AlphaAnimation效果要好，可避免出现闪烁问题。
五、扫描指定的文件
用途：从本软件新增、修改、删除图片、文件某一个文件（音频、视频）需要更新系统媒体库时使用，不必扫描整个SD卡。
六、Dip转px
return (int)TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dip, ctx.getResources().getDisplayMetrics());
}
用途：难免在Activity代码中设置位置、大小等，本方法就很有用了！
七、发送不重复的通知（Notification）
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);
}
八、代码设置TextView的样式
使用过自定义Dialog可能马上会想到用如下代码：
new TextView(this,null,R.style.text_style);
但你运行这代码你会发现毫无作用！正确用法：
new TextView(new ContextThemeWrapper(this, R.style.text_style))
九、 ip地址转成8位十六进制串
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();
}
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 "";
}
ip:192.168.68.128 16 =>hex :c0a84480
十、WebView保留缩放功能但隐藏缩放控件
mWebView.getSettings().setBuiltInZoomControls(true);
if (DeviceUtils.hasHoneycomb())
mWebView.getSettings().setDisplayZoomControls(false);
注意：setDisplayZoomControls是在API Level 11中新增。
十一、获取网络类型名称
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";
}
}
十二、Android解压Zip包
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
out.write(buffer, 0, len);
out.flush();
}
out.close();
}
}//end of while
inZip.close();
}//end of func
十三、 从assets中读取文本和图片资源
public static String getTextFromAssets(final Context context, String fileName) {
String result = "";
try {
InputStream in = context.getResources().getAssets().open(fileName);
// 获取文件的字节数
int lenght = in.available();
// 创建byte数组
byte[] buffer = new byte[lenght];
// 将文件中的数据读到byte数组中
in.read(buffer);
result = EncodingUtils.getString(buffer, "UTF-8");
in.close();
} catch (Exception e) {
e.printStackTrace();
}
return result;
}
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;
}
