Android_CodeWiki_01

 记录常用代码片,以备不时之需..wkakak,开始:

   1、 精确获取屏幕尺寸(例如:3.5、4.0、5.0寸屏幕) 

  

  public static double getScreenPhysicalSize(Activity ctx) {
DisplayMetrics dm = new DisplayMetrics();
ctx.getWindowManager().getDefaultDisplay().getMetrics(dm);
double diagonalPixels = Math.sqrt(Math.pow(dm.widthPixels, 2) + Math.pow(dm.heightPixels, 2));
return diagonalPixels / (160 * dm.density);
} 一般小于7寸的,都是非平板,属于正常智能机系列

  2、 判断是否是平板(官方用法)

  

public static boolean isTablet(Context context) {
return (context.getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) >= Configuration.SCREENLAYOUT_SIZE_L ARGE;
}

3、 文字根据状态更改颜色 android:textColor 

  

<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:color="#53c1bd" android:state_selected="true"/>
<item android:color="#53c1bd" android:state_focused="true"/>
<item android:color="#53c1bd" android:state_pressed="true"/>
<item android:color="#777777"/>
</selector> 放在工程 res/color/目录下

4、背景色根据状态更改颜色 android:backgroup

     

 <selector xmlns:android="http://schemas.android.com/apk/res/android">

     <item android:state_selected="true"><shape>
<gradient android:angle="0" android:centerColor="#00a59f" android:endColor="#00a59f" android:startColor="#00a59f" />
</shape></item>
<item android:state_focused="true"><shape>
<gradient android:angle="0" android:centerColor="#00a59f" android:endColor="#00a59f" android:startColor="#00a59f" />
</shape></item>
<item android:state_pressed="true"><shape>
<gradient android:angle="0" android:centerColor="#00a59f" android:endColor="#00a59f" android:startColor="#00a59f" />
</shape></item>
<item><shape>
<gradient android:angle="0" android:centerColor="#00ff00" android:endColor="00ff00" android:startColor="00ff00" />
</shape></item> </selector>   如果直接给背景色color会报错。

5、 启动APK的默认Activity

  

 public static void startApkActivity(final Context ctx, String packageName) {
PackageManager pm = ctx.getPackageManager();
PackageInfo pi;
try {
pi = pm.getPackageInfo(packageName, 0);
Intent intent = new Intent(Intent.ACTION_MAIN, null);
intent.addCategory(Intent.CATEGORY_LAUNCHER);
intent.setPackage(pi.packageName); List<ResolveInfo> apps = pm.queryIntentActivities(intent, 0); ResolveInfo ri = apps.iterator().next();
if (ri != null) {
String className = ri.activityInfo.name;
intent.setComponent(new ComponentName(packageName, className));
ctx.startActivity(intent);
}
} catch (NameNotFoundException e) {
Log.e("startActivity", e);
}
}

7、计算字宽

  

  public static float GetTextWidth(String text, float Size) {
TextPaint FontPaint = new TextPaint();
FontPaint.setTextSize(Size);
return FontPaint.measureText(text);
}

8、获取应用程序下所有Activity 

  

  public static ArrayList<String> getActivities(Context ctx) {
ArrayList<String> result = new ArrayList<String>();
Intent intent = new Intent(Intent.ACTION_MAIN, null);
intent.setPackage(ctx.getPackageName());
for (ResolveInfo info : ctx.getPackageManager().queryIntentActivities(intent, 0)) {
result.add(info.activityInfo.name);
}
return result;
}

9、检测字符串中是否包含汉字

  

public static boolean checkChinese(String sequence) {
final String format = "[\\u4E00-\\u9FA5\\uF900-\\uFA2D]";
boolean result = false;
Pattern pattern = Pattern.compile(format);
Matcher matcher = pattern.matcher(sequence);
result = matcher.find();
return result;
} 检测字符串中只能包含:中文、数字、下划线(_)、横线(-)  public static boolean checkNickname(String sequence) {
        final String format = "[^\\u4E00-\\u9FA5\\uF900-\\uFA2D\\w-_]";
        Pattern pattern = Pattern.compile(format);
        Matcher matcher = pattern.matcher(sequence);
        return !matcher.find();
    } 

10、检查有没有应用程序来接受处理你发出的intent

  

  public static boolean isIntentAvailable(Context context, String action) {
final PackageManager packageManager = context.getPackageManager();
final Intent intent = new Intent(action);
List<ResolveInfo> list = packageManager.queryIntentActivities(intent, PackageManager.MATCH_DEFAULT_ONLY);
return list.size() > 0;
}

参考:http://www.cnblogs.com/over140/archive/2013/03/05/2706068.html

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