android 用到的技巧集

1.Drawable的使用

android.graphics.drawable

Most often you will deal with Drawable as the type of resource retrieved for drawing things to the screen; the Drawable class provides a generic API for dealing with an underlying visual resource that may take a variety of forms.

最经常会处理Drawable作为类型的资源回收绘制到屏幕上的东西; Drawable类提供了一个通用的API来处理一个基本的视觉资源，可以采取多种形式。（讲的有点抽象）讲白点就是获取res下的参数

例：改变TextView文字颜色-引用Drawable颜色常熟及背景色

values下的color.xml

 <?xml version="1.0" encoding="utf-8" ?>   <resources>  <drawable name="darkgray">#808080FF</drawable>   <drawable name="white">#FFFFFFFF</drawable>   </resources>

对文本框的背景色进行设置

    Resources resources = getBaseContext().getResources();    Drawable HippoDrawable = resources.getDrawable(R.drawable.white);    mTextView01.setBackgroundDrawable(HippoDrawable);

2.获取手机屏幕大小

DisplayMetrics  dm = new DisplayMetrics();getWindowManager().getDefaultDisplay().getMetrics(dm);Stirng width = dm.widthPixels;Stirng heiht = dm.heightPixels;

3.Android style 机制

仅仅是加了一个Style. 一个Style就能够实现控件的显示效果样式么?Android的Style机制真的很强大.
例:

<?xml version="1.0" encoding="utf-8" ?> - <resources>- <style name="DavidStyleText1">  <item name="android:textSize">18sp</item>   <item name="android:textColor">#EC9237</item>   </style>- <style name="DavidStyleText2">  <item name="android:textSize">14sp</item>   <item name="android:textColor">#FF7F7C</item>   <item name="android:fromAlpha">0.0</item>   <item name="android:toAlpha">0.0</item>   </style>  </resources>

<?xml version="1.0" encoding="utf-8" ?> - <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:background="@drawable/white" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent">- <!--  应用模式1的TextView   -->   <TextView style="@style/DavidStyleText1" android:layout_width="fill_parent" android:layout_height="wrap_content" android:gravity="center_vertical|center_horizontal" android:text="@string/str_text_view1" /> - <!--  应用模式2的TextView   -->   <TextView style="@style/DavidStyleText2" android:layout_width="fill_parent" android:layout_height="wrap_content" android:gravity="center_vertical|center_horizontal" android:text="@string/str_text_view2" />   </LinearLayout>

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