零碎知识点

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一、获取系统版本号：

PackageInfo info = this.getPackageManager().getPackageInfo(this.getPackageName(), 0);
int versionCode=nfo.versionCode
string versionName=info.versionNam

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二、获取系统信息：

String archiveFilePath="sdcard/download/Law.apk";//安装包路径
PackageManager pm = getPackageManager();
PackageInfo info = pm.getPackageArchiveInfo(archiveFilePath, PackageManager.GET_ACTIVITIES);
if(info != null){
ApplicationInfo appInfo = info.applicationInfo;
String appName = pm.getApplicationLabel(appInfo).toString();
String packageName = appInfo.packageName; //得到安装包名称
String version=info.versionName; //得到版本信息
Toast.makeText(test4.this, "packageName:"+packageName+";version:"+version, Toast.LENGTH_LONG).show();
Drawable icon = pm.getApplicationIcon(appInfo);//得到图标信息
TextView tv = (TextView)findViewById(R.id.tv); //显示图标
tv.setBackgroundDrawable(icon);

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三、获取安装路径和已安装程序列表

(1)android中获取当前程序路径
getApplicationContext().getFilesDir().getAbsolutePath()
(2)android取已安装的程序列表
List<PackageInfo> packageInfoList = getPackageManager().getInstalledPackages(0);

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四、获取图片、应用名、包名

PackageManager pManager = MessageSendActivity.this.getPackageManager();
List<PackageInfo> appList = Utils.getAllApps(MessageSendActivity.this);
for(int i=0;i<appList.size();i++) {
PackageInfo pinfo = appList.get(i);
ShareItemInfo shareItem = new ShareItemInfo();
//set Icon
shareItem.setIcon(pManager.getApplicationIcon(pinfo.applicationInfo));

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解决listview上 Item上有按钮时 item本身不能点击的问题：

1. 在item试图上面添加代码： android:descendantFocusability="blocksDescendants"
2.在listview里添加代码 android:focusable="true"

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不让文本框输入中文：

android:digits="1234567890qwertyuiopasdfghjklzxcvbnm`-=[]\;,./~!@#$%^*()_+}{:?&<>"'"
这样就不会输入中文了。

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获取屏幕宽高

DisplayMetrics displayMetrics = new DisplayMetrics();
this.getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
int height = displayMetrics.heightPixels;
int width = displayMetrics.widthPixels;

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程序中安装apk

Intent intent = new Intent();
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.setAction(android.content.Intent.ACTION_VIEW);
intent.setDataAndType(Uri.fromFile(“APK”),"application/vnd.android.package-archive");
startActivity(intent);

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获取设备型号、SDK版本及系统版本

String device_model = Build.MODEL; // 设备型号
String version_sdk = Build.VERSION.SDK; // 设备SDK版本
String version_release = Build.VERSION.RELEASE; // 设备的系统版本

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当listview滑动到底部或者顶部，会出现金色动画，去掉的办法

listView.setOverScrollMode(View.OVER_SCROLL_NEVER);

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获取应用程序下所有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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检测字符串中是否包含汉字

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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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();
}

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设置窗口格式为半透明

getWindow().setFormat(PixelFormat.TRANSLUCENT);

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全屏显示窗口

requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

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调浏览器载入网址

Uri uri = Uri.parse("http://www.google.com");
Intent it = new Intent(Intent.ACTION_VIEW, uri);
startActivity(it);

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取得内存大小

ActivityManager.MemoryInfo outInfo = new ActivityManager.MemoryInfo();
activityManager.getMemoryInfo(outInfo);
//可用内存
outInfo.availMem
//是否在低内存状态
outInfo.lowMemory

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取得ScrollView的实际高度

scrollview.getHeight()
scrollview.getMeasuredHeight()
scrollview.compute()
scrollview.getLayoutParams().height

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取得IP地址

A.
//Connect via WIFI 通过wifi
WifiManager wifiManager = (WifiManager) getSystemService(WIFI_SERVICE);
WifiInfo wifiInfo = wifiManager.getConnectionInfo();
int ipAddress = wifiInfo.getIpAddress();
B.
//Connect via GPRS通过gprs
public String getLocalIpAddress(){
try{
for(Enumeration en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements();){
NetworkInterface intf = en.nextElement();
for (Enumeration enumIpAddr = intf.getInetAddresses(); enumIpAddr.hasMoreElements();){
InetAddress inetAddress = enumIpAddr.nextElement();
if (!inetAddress.isLoopbackAddress()){
return inetAddress.getHostAddress().toString();
}
}
}
}catch (SocketException ex){
Log.e(S.TAG, ex.toString());
}
return null;
}

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图片旋转

Bitmap bitmapOrg = BitmapFactory.decodeResource(this.getContext().getResources(), R.drawable.moon);
Matrix matrix = new Matrix();
matrix.postRotate(-90);//旋转的角度
Bitmap resizedBitmap = Bitmap.createBitmap(bitmapOrg, 0, 0,
bitmapOrg.getWidth(), bitmapOrg.getHeight(), matrix, true);
BitmapDrawable bmd = new BitmapDrawable(resizedBitmap);

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获取手机号码

//创建电话管理
TelephonyManager tm = (TelephonyManager)
//与手机建立连接
activity.getSystemService(Context.TELEPHONY_SERVICE);
//获取手机号码
String phoneId = tm.getLine1Number();
//记得在manifest file中添加
<uses-permission
android:name="android.permission.READ_PHONE_STATE" />
//程序在模拟器上无法实现，必须连接手机

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查看电池使用情况

Intent intentBatteryUsage = new Intent(Intent.ACTION_POWER_USAGE_SUMMARY);
startActivity(intentBatteryUsage);

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android中添加新的联系人

private Uri insertContact(Context context, String name, String phone) {
ContentValues values = new ContentValues();
values.put(People.NAME, name);
Uri uri = getContentResolver().insert(People.CONTENT_URI, values);
Uri numberUri = Uri.withAppendedPath(uri, People.Phones.CONTENT_DIRECTORY);
values.clear();
values.put(Contacts.Phones.TYPE, People.Phones.TYPE_MOBILE);
values.put(People.NUMBER, phone);
getContentResolver().insert(numberUri, values);
return uri;
}

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android获取存储卡路径以及使用情况

/** 获取存储卡路径 */
File sdcardDir=Environment.getExternalStorageDirectory();
/** StatFs 看文件系统空间使用情况 */
StatFs statFs=new StatFs(sdcardDir.getPath());
/** Block 的 size*/
Long blockSize=statFs.getBlockSize();
/** 总 Block 数量 */
Long totalBlocks=statFs.getBlockCount();
/** 已使用的 Block 数量 */
Long availableBlocks=statFs.getAvailableBlocks();

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android中获取IP地址

public String getLocalIpAddress() {
try {
for (Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces();
en.hasMoreElements();) {
NetworkInterface intf = en.nextElement();
for (Enumeration<InetAddress> enumIpAddr = intf.getInetAddresses();
enumIpAddr.hasMoreElements();) {
InetAddress inetAddress = enumIpAddr.nextElement();
if (!inetAddress.isLoopbackAddress()) {
return inetAddress.getHostAddress().toString();
}
}
}
} catch (SocketException ex) {
Log.e(LOG_TAG, ex.toString());
}
return null;
}