android一些技巧
16lz
2022-04-04
EditText ed = new EditText(this); Editable eb = ed.getEditableText(); //获取光标位置 int position = ed.getSelectionStart(); //指定位置插入字符 eb.insert(position, "XXX"); //插入图片 //定义图片所占字节数（“Tag”的长度） SpannableString ss = new SpannableString("Tag"); //定义插入图片 Drawable drawable = getResources().getDrawable(R.drawable.icon); ss.setSpan(new ImageSpan(drawable,ImageSpan.ALIGN_BASELINE), 0, ss.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE); drawable.setBounds(2, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight()); //插入图片 eb.insert(position, ss); //设置可输入最大字节数 ed.setFilters(new InputFilter[]{new InputFilter.LengthFilter(10)}); //拉起lancher桌面 Intent i = new Intent(Inten.ACTION_MAIN); i.addCategory(Inten.CATEGORT_HOME); startActivity(i); //去掉List拖动时的阴影 list.setCacheColorHint(0); // 通过资源名称获取资源id 1.Field f= (Field)R.drawable.class.getDeclaredField("Name"); int id=f.getInt(R.drawable.class); 2.int id = getResources().getIdentifier(getPackageName()+":drawable/Name", null,null); // timer TimerTask用法 mTimer = new Timer(); mTimerTask = new TimerTask() {@Overridepublic void run() {mProgress.setProgress(mMediaPlayer.getCurrentPosition());mHandler.sendEmptyMessage(0);}};mTimer.schedule(mTimerTask, 0, 1000); // 在a.apk启动b.apk的实现 //1.a.apk实现Intent mIntent = new Intent("package.MainActivity"); startActivity(mIntent);finish(); // b.apk在mainfest中配置 <intent-filter> <action android:name="package.MainActivity" /> <category android:name="android.intent.category.DEFAULT" /> </intent-filter>//Android 获取存储卡路径和空间使用情况 /** 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(); //Android 为Activity屏幕的标题添加图标Window win = getWindow(); win.requestFeature(Window.FEATURE_LEFT_ICON); setContentView(R.layout.mylayout); win.setFeatureDrawableResource(Window.FEATURE_LEFT_ICON, R.drawable.icon);//图片缩放1.ThumbnailUtils.extractThumbnail(bitmap,200,100)2. //使用Bitmap加Matrix来缩放 public static Drawable resizeImage(Bitmap bitmap, int w, int h) { Bitmap BitmapOrg = bitmap; int width = BitmapOrg.getWidth(); int height = BitmapOrg.getHeight(); int newWidth = w; int newHeight = h; float scaleWidth = ((float) newWidth) / width; float scaleHeight = ((float) newHeight) / height; Matrix matrix = new Matrix(); matrix.postScale(scaleWidth, scaleHeight); // if you want to rotate the Bitmap // matrix.postRotate(45); Bitmap resizedBitmap = Bitmap.createBitmap(BitmapOrg, 0, 0, width, height, matrix, true); return new BitmapDrawable(resizedBitmap); } 3. //使用BitmapFactory.Options的inSampleSize参数来缩放 public static Drawable resizeImage2(String path, int width,int height) { BitmapFactory.Options options = new BitmapFactory.Options(); options.inJustDecodeBounds = true;//不加载bitmap到内存中 BitmapFactory.decodeFile(path,options); int outWidth = options.outWidth; int outHeight = options.outHeight; options.inDither = false; options.inPreferredConfig = Bitmap.Config.ARGB_8888; options.inSampleSize = 1; if (outWidth != 0 && outHeight != 0 && width != 0 && height != 0) { int sampleSize=(outWidth/width+outHeight/height)/2; Log.d(tag, "sampleSize = " + sampleSize); options.inSampleSize = sampleSize; } options.inJustDecodeBounds = false; return new BitmapDrawable(BitmapFactory.decodeFile(path, options)); }
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