Android---常用方法
1、获取资源： Resources res = getBaseContext().getResources(); Drawable draw=res.getDrawable(R.drawable.icon);2、获得数组: String[] ary = getResources().getStringArray(R.array.ary); 3、自动提示框：代码 String[] arrays=new String[]{"a","ab","abc","bc","bcde","ee"};actalert=(AutoCompleteTextView)findViewById(R.id.actalert);ArrayAdapter<String> adapter=new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line, arrays);actalert.setAdapter(adapter);mactalert=(MultiAutoCompleteTextView)findViewById(R.id.mactvalert);mactalert.setAdapter(adapter); // 设置多个值之间的分隔符，此处为逗号mactalert.setTokenizer(new MultiAutoCompleteTextView.CommaTokenizer());4、spinner设置数据源代码 spncolor.setPrompt("请选择");ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this, R.array.attr, android.R.layout.simple_spinner_item);adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);spncolor.setAdapter(adapter);? 5、显示当前时间：SimpleDateFormat sdf =new SimpleDateFormat("HH:mm:ss"); // 将当前时间显示在TextView组件中 tvTime.setText("当前时间："+ sdf.format(new Date()));6、代码添加布局文件代码 AbsListView.LayoutParams lp =new AbsListView.LayoutParams( ViewGroup.LayoutParams.FILL_PARENT, 64); TextView text =new TextView(activity); text.setLayoutParams(lp); text.setTextSize(20); text.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT); text.setPadding(36, 0, 0, 0); text.setText(s); 7、自定义窗口标题栏代码 requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);//自定义标题栏setContentView(R.layout.main);//为标题栏设置一个xml布局getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.title_custom); 8、Activity仿Dialog Theme（加图标和标题其实就是Activity的icon和titile）(1)、自定义样式<style name="Theme.CustomDialog" parent="android:style/Theme.Dialog"><item name="android:windowBackground">@drawable/filled_box</item></style>@drawable/filled_box：资源文件中新建drawable文件夹，新建filled_box样式xml代码 <shape xmlns:android="http://schemas.android.com/apk/res/android"><solid android:color="#f0600000"/><stroke android:width="3dp" color="#ffff8080"/><corners android:radius="3dp"/><padding android:left="10dp" android:top="10dp"android:right="10dp" android:bottom="10dp"/></shape>（2）Manifest.xml中配置Acitivity样式代码 <activity android:name=".Main"android:label="@string/app_name"android:theme="@android:style/Theme.Dialog"><intent-filter><action android:name="android.intent.action.MAIN"/><category android:name="android.intent.category.LAUNCHER"/></intent-filter></activity>(3)为Activity设置图标代码 //设定窗口模式(仿Dialog中的icon，带有一个左图标)requestWindowFeature(Window.FEATURE_LEFT_ICON);setContentView(R.layout.main);//设置图片资源getWindow().setFeatureDrawableResource(Window.FEATURE_LEFT_ICON, R.drawable.icon); 9、从一个Activity1到另一个Activity2，当在第二个Activity2按返回键不出现Activity1的做法是在打开Activity2的同时关闭Activity1Intent intent =new Intent(Main.this, fowardwidget.class);startActivity(intent);finish(); 10、允许TextView的文本值拼接（1）允许在TextView的文本值后添加buffer texttv.setText(tv.getText(),TextView.BufferType.EDITABLE);(2)使用Editable对象添加buffer textEditable text=(Editable)tv.getText();text.append("editable");text.append("\n"): 11、如果历史栈中包含Activity，打开此Activity从栈中放到栈顶层而不是从新打开ActivityIntent intent =new Intent(ReorderFour.this, ReorderTwo.class);intent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);startActivity(intent);12、避免输入法面板遮挡，在manifest.xml中activity中设置android:windowSoftInputModeandroid:windowSoftInputMode="stateVisible|adjustResize" 13、获取当前手机壁纸和设置手机壁纸（wallpaper）(1)获取当前壁纸WallpaperManager wm=WallpaperManager.getInstance(this);Drawable wallpaper=wpm.getDrawable();（2）设置当前壁纸，同时要添加壁纸设置权限imapaper.setDrawingCacheEnabled(true);Drawable drawale=this.getResources().getDrawable(R.drawable.bg);imapaper.setImageDrawable(drawale);wpm.setBitmap(imapaper.getDrawingCache());<uses-permission android:name="android.permission.SET_WALLPAPER"></uses-permission> 14、常见通过系统服务得到的实例化对象NotificationManager nm=(NotificationManager)getSystemService(NOTIFICATION_SERVICE); 15、检查网络是否连接代码 //检查网络是否连接publicboolean checkIntent(){ConnectivityManager mannager=(ConnectivityManager)this.getSystemService(CONNECTIVITY_SERVICE);NetworkInfo info=mannager.getActiveNetworkInfo();if(info==null||!info.isConnected()){returnfalse;}if(info.isRoaming()){returntrue;}returntrue;}<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission> 16、从资源文件中（asset）读取文本文档//获得输入流InputStream in=getAssets().open("read_asset.txt");int size=in.available();//将输入流读到字节数组中（内存）byte[] buffer=newbyte[size];in.read(buffer);in.close();String text=new String(buffer); 17、TextView、Button等设置文本滚动（跑马灯效果），控件必须获得焦点才能有滚动效果，并且文字长度大于控件长度android:singleLine="true"android:ellipsize="marquee"android:focusable="true" android:marqueeRepeatLimit="marquee_forever" //marquee_forever:一直滚动下去，n(整数）：滚动n次