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
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
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
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
代码
//
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);
}