Android---常用方法（转）
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：
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
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
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);
custom_title.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<TextView android:id="@+id/tvtitle"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:layout_alignParentLeft="true"></TextView>
<LinearLayout android:layout_width="wrap_content" android:layout_height="wrap_content"
android:layout_toRightOf="@+id/tvtile" android:orientation="horizontal"
android:layout_alignParentRight="true" android:gravity="center">
<Button android:text="@string/answer" android:id="@+id/btnanswer"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:background="@color/btn_inter" android:layout_marginRight="8dp"
android:gravity="center" android:paddingTop="2dp"></Button>
<Button android:text="@string/submit" android:id="@+id/btnsubmit"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:background="@color/btn_inter" android:layout_marginRight="8dp"
android:gravity="center" android:paddingTop="2dp"></Button>
</LinearLayout>
</RelativeLayout>
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
<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
<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
//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Activity1
Intent 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 text
tv.setText(tv.getText(),TextView.BufferType.EDITABLE);
(2)使用Editable对象添加buffer text
Editable 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Activity
Intent 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:windowSoftInputMode
android: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
//检查网络是否连接
public boolean checkIntent(){
ConnectivityManager mannager=(ConnectivityManager)
this.getSystemService(CONNECTIVITY_SERVICE);
NetworkInfo info=mannager.getActiveNetworkInfo();
if(info==null || !info.isConnected()){
return false;
}
if(info.isRoaming()){
return true;
}
return true;
}
<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=new byte[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
18、TextView文本添加下划线
TextView textView = (TextView)findViewById(R.id.testView);
textView.setText(Html.fromHtml("<u>"+"hahaha"+"</u>"));
19、TextView添加图片
String src=""+R.drawable.qq;
Html.ImageGetter imageGetter =new ImageGetter() {
Drawable draw=null;
@Override
public Drawable getDrawable(String source) {
// TODO Auto-generated method stub
int id=Integer.parseInt(source.trim());
draw=getResources().getDrawable(id);
draw.setBounds(0, 0, draw.getIntrinsicWidth(), draw.getIntrinsicHeight());
return draw;
}
};
tvquestion.append(Html.fromHtml("<img src="+src+"", imageGetter, null));
20、秒转成00：00:00
int hour=time/60/60%60;
int minute = time/60%60;
int second = time%60;
String strhour=hour<10 ? "0" + hour : "" + hour;
String strminutes=minute<10 ? "0" + minute : "" + minute;
String strseconds=second < 10 ? "0" + second : "" + second;
tvtimer.setText(strhour+":"+strminutes+":"+strseconds);
21、TextView添加滚动条
<ScrollView android:id="@+id/sv_e8_question"
android:layout_width="fill_parent" android:layout_height="180dp"
android:scrollbarStyle="outsideOverlay">
<TextView android:text="@string/question" android:id="@+id/tv_e8_question"
android:layout_width="fill_parent" android:layout_height="wrap_content"
android:paddingTop="5dp" android:paddingLeft="5dp"></TextView>
</ScrollView>
22、Activity自动销毁时调用onSaveInstanceState()方法保存配置信息:可多Activity共享
@Override
public void onSaveInstanceState(Bundle outState){
SharedPreferences.Editor editor=getSharedPreferences("sp_timer", 0).edit();
editor.putInt(arg0, arg1);
super.onSaveInstanceState(outState);
}
单个Activity保存
@Override
public void onSaveInstanceState(Bundle outState){
SharedPreferences.Editor editor=this.getPreferences(0).edit();
editor.putInt(arg0, arg1);
super.onSaveInstanceState(outState);
}
