Android杂谈

在application标签内获取meta元素的值获取mata标签

• 当value是字符串时，使用getString获取值

<meta-data     android:name="UMENG_CHANNEL"     android:value="china"/> 

try {            ApplicationInfo appInfo = getPackageManager()                    .getApplicationInfo(getPackageName(),                            PackageManager.GET_META_DATA);            String UMENG_CHANNEL = appInfo.metaData.getString("UMENG_CHANNEL");            Log.d("meta:", "UMENG_CHANNEL=" + UMENG_CHANNEL);        } catch (Exception e) {            Log.d("meta:", "exception");        }

• 当value是字符串数字时，需要使用getInt获取值，否则获取值为null

<meta-data    android:name="width"    android:value="1080"/>

try {        ApplicationInfo appInfo = getPackageManager()                .getApplicationInfo(getPackageName(),                        PackageManager.GET_META_DATA);        int width=appInfo.metaData.getInt("design_width",0);        Log.d("meta:", "width=" + width);    } catch (Exception e) {        Log.d("meta:", "exception");    }

设置横竖屏

• xml中设置

强制为竖屏

<activity    android:name="com.cn.MainActivity"    android:screenOrientation="portrait"/>

强制为横屏

<activity    android:name="com.cn.MainActivity"    android:screenOrientation="landscape"/> 

• 代码中设置

setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);  //强制为竖屏setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE); //强制为横屏

注意

这种设置会导致生命周期重新走一遍可在AndroidManifest.xml中给Activity添加

android:configChanges="orientation|keyboardHidden|screenSize"

获取屏幕宽高、密度比

WindowManager wm = (WindowManager) this.getSystemService(Context.WINDOW_SERVICE);int width = wm.getDefaultDisplay().getWidth();int height = wm.getDefaultDisplay().getHeight();

WindowManager wm1 = this.getWindowManager();int width1 = wm1.getDefaultDisplay().getWidth();int height1 = wm1.getDefaultDisplay().getHeight();

以上过时

推荐

WindowManager manager = this.getWindowManager();DisplayMetrics metric = new DisplayMetrics();manager.getDefaultDisplay().getMetrics(metric);int width = metric.widthPixels;     // 屏幕宽度（像素）int height = metric.heightPixels;   // 屏幕高度（像素）float density = metric.density;      // 屏幕密度（0.75 / 1.0 / 1.5）int densityDpi = metric.densityDpi;  // 屏幕密度DPI（120 / 160 / 240）

Resources resources = this.getResources();DisplayMetrics dm = resources.getDisplayMetrics();int width = dm.widthPixels;int height = dm.heightPixels;float density = dm.density;

分辨率和hdpi对照表

“HVGA mdpi”
“WVGA hdpi “
“FWVGA hdpi “
“QHD hdpi “
“720P xhdpi”
“1080P xxhdpi “

Android图标尺寸

Android中Button按钮设置英文全部变成大写问题

添加属性android:textAllCaps=”false”
源码默认设置的是true，全部变成大写