Android实用代码片段(一)

1、创建快捷方式：

//添加权限<uses-permission android:name="com.android.launcher.permission.INSTALL_SHORTCUT"/> public void installShortCut(String name, int icon, Intent intent) {        Intent shortcut = new Intent("com.android.launcher.action.INSTALL_SHORTCUT");        // 快捷方式的名称        shortcut.putExtra(Intent.EXTRA_SHORTCUT_NAME, name);        shortcut.putExtra("duplicate", false); // 不允许重复创建        // 快捷方式的图标        ShortcutIconResource iconRes = ShortcutIconResource.fromContext(mContext, icon);        shortcut.putExtra(Intent.EXTRA_SHORTCUT_ICON_RESOURCE, iconRes);        intent.setAction("android.intent.action.MAIN");// 桌面图标和应用绑定，卸载应用后系统会同时自动删除图标        intent.addCategory("android.intent.category.LAUNCHER");// 桌面图标和应用绑定，卸载应用后系统会同时自动删除图标        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);        intent.setFlags(Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);        shortcut.putExtra(Intent.EXTRA_SHORTCUT_INTENT, intent);        mContext.sendBroadcast(shortcut);    }

2、删除快捷方式：

//权限<uses-permission android:name="com.android.launcher.permission.UNINSTALL_SHORTCUT" />public static void deleteShortcut(Context context , String shortcutName ,                                      Intent actionIntent , boolean isDuplicate) {        Intent shortcutIntent = new Intent ("com.android.launcher.action.UNINSTALL_SHORTCUT");        shortcutIntent.putExtra(Intent.EXTRA_SHORTCUT_NAME ,shortcutName);        shortcutIntent.putExtra("duplicate" , isDuplicate);        shortcutIntent.putExtra(Intent.EXTRA_SHORTCUT_INTENT , actionIntent);        context.sendBroadcast(shortcutIntent);    }

3、判断快捷方式的存在与否：

public String getLauncherPackageName(Context context) {        Intent intent = new Intent(Intent.ACTION_MAIN);        intent.addCategory(Intent.CATEGORY_HOME);        ResolveInfo res = context.getPackageManager()                .resolveActivity(intent, 0);        if (res.activityInfo == null) {            return "";        }        if (res.activityInfo.packageName.equals("android")) {            return "";        } else {            return res.activityInfo.packageName;        }    }    public boolean hasShortcut(String name) {        String url;        String packageName = getLauncherPackageName(mContext);        if (packageName == null || packageName.equals("")                || packageName.equals("com.android.launcher")) {            int sdkInt = android.os.Build.VERSION.SDK_INT;            if (sdkInt < 8) { // Android 2.1.x(API 7)以及以下的                packageName = "com.android.launcher.settings";            } else if (sdkInt < 19) {// Android 4.4以下                packageName = "com.android.launcher2.settings";            } else {// 4.4以及以上                packageName = "com.android.launcher3.settings";            }        }        url = "content://" + packageName + ".settings/favorites?notify=true";        try {            ContentResolver resolver = mContext.getContentResolver();            Cursor cursor = resolver.query(Uri.parse(url), new String[] {                            "title", "iconResource" }, "title=?",                    new String[] { name }, null);            if (cursor != null && cursor.getCount() > 0) {                return true;            }        } catch (Exception e) {            if (e != null) {                e.printStackTrace();            }        }        return false;    }

4、显示或隐藏虚拟键盘：

显示：  InputMethodManager imm = (InputMethodManager)(getSystemService(Context.INPUT_METHOD_SERVICE)); imm.toggleSoftInput(InputMethodManager.SHOW_FORCED, 0); 隐藏：  InputMethodManager imm = (InputMethodManager)(getSystemService(Context.INPUT_METHOD_SERVICE)); imm.hideSoftInputFromWindow(m_edit.getWindowToken(), 0);

5、从assets中读取文本和图片资源：

/** 从assets 文件夹中读取文本数据 */    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;    }    /** 从assets 文件夹中读取图片 */    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;    }

6、进行px和dp之间的转换：

import android.content.Context;  public class DensityUtil {      /** * 根据手机的分辨率从 dp 的单位 转成为 px(像素) */      public static int dip2px(Context context, float dpValue) {          final float scale = context.getResources().getDisplayMetrics().density;          return (int) (dpValue * scale + 0.5f);      }      /** * 根据手机的分辨率从 px(像素) 的单位 转成为 dp */      public static int px2dip(Context context, float pxValue) {          final float scale = context.getResources().getDisplayMetrics().density;          return (int) (pxValue / scale + 0.5f);      }  }

7、检查有没有应用程序来接受处理你发出的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;    }

8、获取网络类型名称：

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";        }    }

9、获取网络类型名称：

/** * 解压一个压缩文档 到指定位置 * * @param zipFileString 压缩包的名字 * @param outPathString 指定的路径 * @throws 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

10、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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