[置顶] Android常用方法

时间:2023-01-18 19:09:41
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

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-permissionandroid: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-permissionandroid: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