【收藏篇】Android 开发中常用的10种工具类
导语
Android开发中，收集一些常用的代码工具类是非常重要的。现在Android开发技术已经很成熟了，很多代码大牛已经写出了很多框架和工具类，我们现在应该要站在巨人的肩膀上做开发了。今天我把平时开发中收集最常用的 10 个工具类，分享给大家。以后开发中合理利用，对于在平时开发中的效率是非常有帮助的 。
1安装应用APK
// 安装应用APK private void installApk(String apkFilePath) { File apkfile = new File(apkFilePath);
if (!apkfile.exists()) {
return; } Intent i = new Intent(Intent.ACTION_VIEW); i.setDataAndType(Uri.parse("file://" + apkfile.toString()), "application/vnd.android.package-archive"); startActivity(i); }}
2MD5算法
public final static String MD5(String s) {
char hexDigits[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
try {
byte[] btInput = s.getBytes(); // 获得MD5摘要算法的 MessageDigest 对象 MessageDigest mdInst = MessageDigest.getInstance("MD5"); // 使用指定的字节更新摘要 mdInst.update(btInput); // 获得密文 byte[] md = mdInst.digest(); // 把密文转换成十六进制的字符串形式 int j = md.length;
char str[] = new char[j * 2];
int k = 0; //把字节转换成对应的字符串 for (int i = 0; i < j; i++) {
byte byte0 = md[i]; str[k++] = hexDigits[byte0 >>> 4 & 0xf]; str[k++] = hexDigits[byte0 & 0xf]; }
return new String(str); } catch (Exception e) { e.printStackTrace();
return null; } }
3判断现在是否有网络
private boolean NetWorkStatus() { ConnectivityManager cwjManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); cwjManager.getActiveNetworkInfo();
boolean netSataus = true;
if (cwjManager.getActiveNetworkInfo() != null) { netSataus = cwjManager.getActiveNetworkInfo().isAvailable(); Toast.makeText(this, "网络已经打开", Toast.LENGTH_LONG).show(); }
else { Builder b = new AlertDialog.Builder(this).setTitle("没有可用的网络") .setMessage("是否对网络进行设置？"); b.setPositiveButton("是", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int whichButton) { Intent mIntent = new Intent("/"); ComponentName comp = new ComponentName( "com.android.settings", "com.android.settings.WirelessSettings"); mIntent.setComponent(comp); mIntent.setAction("android.intent.action.VIEW"); startActivityForResult(mIntent,0); } }).setNeutralButton("否", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) { dialog.cancel(); } }).show(); }
return netSataus; }
4获取设备屏幕的宽度高度密度
public class DisplayUtil { /** * 得到设备屏幕的宽度 */ public static int getScreenWidth(Context context) {
return context.getResources().getDisplayMetrics().widthPixels; } /** * 得到设备屏幕的高度 */ public static int getScreenHeight(Context context) {
return context.getResources().getDisplayMetrics().heightPixels; } /** * 得到设备的密度 */ public static float getScreenDensity(Context context) {
return context.getResources().getDisplayMetrics().density; } }
5dp、sp 转换为 px 的工具类
public class DisplayUtil { /** * 将px值转换为dip或dp值，保证尺寸大小不变 */ public static int px2dip(Context context, float pxValue) { final float scale = context.getResources().getDisplayMetrics().density; return (int) (pxValue / scale + 0.5f); } /** * 将dip或dp值转换为px值，保证尺寸大小不变 * * @param dipValue * @param scale * （DisplayMetrics类中属性density） * @return */ public static int dip2px(Context context, float dipValue) {
final float scale = context.getResources().getDisplayMetrics().density;
return (int) (dipValue * scale + 0.5f); } /** * 将px值转换为sp值，保证文字大小不变 * * @param pxValue * @param fontScale * （DisplayMetrics类中属性scaledDensity） * @return */ public static int px2sp(Context context, float pxValue) {
final float fontScale = context.getResources().getDisplayMetrics().scaledDensity;
return (int) (pxValue / fontScale + 0.5f); } /** * 将sp值转换为px值，保证文字大小不变 * * @param spValue * @param fontScale * （DisplayMetrics类中属性scaledDensity） * @return */ public static int sp2px(Context context, float spValue) {
final float fontScale = context.getResources().getDisplayMetrics().scaledDensity;
return (int) (spValue * fontScale + 0.5f); } }
6drawable转bitmap的工具类
/** * drawable转bitmap * * @param drawable * @return */private Bitmap drawableToBitamp(Drawable drawable) {
if (null == drawable) {
return null; }if (drawable instanceof BitmapDrawable) { BitmapDrawable bd = (BitmapDrawable) drawable;
return bd.getBitmap(); }
int w = drawable.getIntrinsicWidth();
int h = drawable.getIntrinsicHeight(); Bitmap bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(bitmap); drawable.setBounds(0, 0, w, h); drawable.draw(canvas);
return bitmap;}
7文章发布模仿朋友圈时间显示
public static String ChangeTime(Date time) { String ftime = ""; Calendar cal = Calendar.getInstance(); // 判断是否是同一天 String curDate = dateFormater2.get().format(cal.getTime()); String paramDate = dateFormater2.get().format(time);
if (curDate.equals(paramDate)) {
int hour = (int) ((cal.getTimeInMillis() - time.getTime()) / 3600000);
if (hour == 0) ftime = Math.max( (cal.getTimeInMillis() - time.getTime()) / 60000, 1) + "分钟前";
else ftime = hour + "小时前";
return ftime; } long lt = time.getTime() / 86400000;
long ct = cal.getTimeInMillis() / 86400000;
int days = (int) (ct - lt);
if (days == 0) {
int hour = (int) ((cal.getTimeInMillis() - time.getTime()) / 3600000);
if (hour == 0) ftime = Math.max( (cal.getTimeInMillis() - time.getTime()) / 60000, 1) + "分钟前"; else ftime = hour + "小时前"; } else if (days == 1) { ftime = "昨天"; } else if (days == 2) { ftime = "前天 "; } else if (days > 2 && days < 31) { ftime = days + "天前"; } else if (days >= 31 && days <= 2 * 31) { ftime = "一个月前"; } else if (days > 2 * 31 && days <= 3 * 31) { ftime = "2个月前"; } else if (days > 3 * 31 && days <= 4 * 31) { ftime = "3个月前"; } else { ftime = dateFormater2.get().format(time); } return ftime; } public static String friendly_time(String sdate) { Date time = null;
if (TimeZoneUtil.isInEasternEightZones()) time = toDate(sdate); else time = TimeZoneUtil.transformTime(toDate(sdate), TimeZone.getTimeZone("GMT+08"), TimeZone.getDefault());
if (time == null) {
return "Unknown"; } String ftime = ""; Calendar cal = Calendar.getInstance(); // 判断是否是同一天 String curDate = dateFormater2.get().format(cal.getTime()); String paramDate = dateFormater2.get().format(time);
if (curDate.equals(paramDate)) {
int hour = (int) ((cal.getTimeInMillis() - time.getTime()) / 3600000);
if (hour == 0) ftime = Math.max( (cal.getTimeInMillis() - time.getTime()) / 60000, 1) + "分钟前"; else ftime = hour + "小时前";
return ftime; } long lt = time.getTime() / 86400000;
long ct = cal.getTimeInMillis() / 86400000;
int days = (int) (ct - lt);
if (days == 0) {
int hour = (int) ((cal.getTimeInMillis() - time.getTime()) / 3600000);
if (hour == 0) ftime = Math.max( (cal.getTimeInMillis() - time.getTime()) / 60000, 1) + "分钟前";
else ftime = hour + "小时前"; } else if (days == 1) { ftime = "昨天"; } else if (days == 2) { ftime = "前天 "; } else if (days > 2 && days < 31) { ftime = days + "天前"; } else if (days >= 31 && days <= 2 * 31) { ftime = "一个月前"; } else if (days > 2 * 31 && days <= 3 * 31) { ftime = "2个月前"; } else if (days > 3 * 31 && days <= 4 * 31) { ftime = "3个月前"; } else { ftime = dateFormater2.get().format(time); } return ftime; }
8时间格式转换工具类
public static String ConverToString(Date date) { DateFormat df = new SimpleDateFormat("yyyy-MM-dd");
return df.format(date); }
public static String ConverToString2(Date date){ DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm");
return df.format(date); }
public static String ConverToString3(Date date){ DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
return df.format(date); }
9验证码倒计时工具类
public class TimeCount extends CountDownTimer {
private Button button; /** * 到计时 * @param millisInFuture 到计时多久,毫秒 * @param countDownInterval 周期 * @param button 按钮 */ public TimeCount(long millisInFuture, long countDownInterval,Button button) {
super(millisInFuture, countDownInterval);
this.button =button; }
public TimeCount(long millisInFuture, long countDownInterval) {
super(millisInFuture, countDownInterval); }
@Override public void onFinish() {// 计时完毕 button.setText("获取验证码"); button.setClickable(true); button.setBackground(MyApplication.getContext().getResources().getDrawable(R.drawable.radius14)); }
@Override public void onTick(long millisUntilFinished) {// 计时过程 button.setClickable(false);//防止重复点击 button.setText(millisUntilFinished / 1000 + "s后重试"); button.setBackground(MyApplication.getContext().getResources().getDrawable(R.drawable.radius_gray)); }}
10屏幕截图工具类
public class ScreenShot {
public static void shoot(Activity a, File filePath) {
if (filePath == null) {
return; }
if (!filePath.getParentFile().exists()) { filePath.getParentFile().mkdirs(); } FileOutputStream fos = null;
try { fos = new FileOutputStream(filePath);
if (null != fos) { takeScreenShot(a).compress(Bitmap.CompressFormat.PNG, 100, fos); } } catch (FileNotFoundException e) { e.printStackTrace(); } finally {
if (fos != null) {
try { fos.flush(); fos.close(); } catch (IOException e) { e.printStackTrace(); } } } } private static Bitmap takeScreenShot(Activity activity) { View view = activity.getWindow().getDecorView(); view.setDrawingCacheEnabled(true); view.buildDrawingCache(); Bitmap bitmap = view.getDrawingCache(); Rect frame = new Rect(); activity.getWindow().getDecorView().getWindowVisibleDisplayFrame(frame);
int statusBarHeight = frame.top;
int width = activity.getWindowManager().getDefaultDisplay().getWidth();
int height = activity.getWindowManager().getDefaultDisplay() .getHeight(); //去掉标题栏 Bitmap b = Bitmap.createBitmap(bitmap, 0, statusBarHeight, width, height - statusBarHeight); view.destroyDrawingCache(); return b; }}