import android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.view.View;

public class MyCustomView extends View {
 /**
  * 第一个构造函数
  */
 public MyCustomView(Context context) {
  this(context, null);
 }

 /**
  * 第二个构造函数
  */
 public MyCustomView(Context context, AttributeSet attrs) {
  this(context, attrs, 0);
 }

 /**
  * 第三个构造函数
  */
 public MyCustomView(Context context, AttributeSet attrs, int defStyle) {
  super(context, attrs, defStyle);
  // TODO:获取自定义属性
 }

 @Override
 protected void onDraw(Canvas canvas) {
  super.onDraw(canvas);
 }
}

<resources>
 <declare-styleable name="MyCustomView">
  <attr name="custom_attr1" format="string" />
  <attr name="custom_attr2" format="string" />
  <attr name="custom_attr3" format="string" />
  <attr name="custom_attr4" format="string" />
 </declare-styleable>
 <attr name="custom_attr5" format="string" />
</resources>

public final class R {
 public static final class attr {
  public static final int custom_attr1=0x7f010038;
  public static final int custom_attr2=0x7f010039;
  public static final int custom_attr3=0x7f01003a;
  public static final int custom_attr4=0x7f01003b;
  public static final int custom_attr5=0x7f010000;
 }
}

public static final class styleable {
  public static final int[] MyCustomView = {
   0x7f010038, 0x7f010039, 0x7f01003a, 0x7f01003b
  };
  public static final int MyCustomView_custom_attr1 = 0;
  public static final int MyCustomView_custom_attr2 = 1;
  public static final int MyCustomView_custom_attr3 = 2;
  public static final int MyCustomView_custom_attr4 = 3;
}

public MyCustomView(Context context, AttributeSet attrs, int defStyleAttr) {
 super(context, attrs, defStyleAttr);

 TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.MyCustomView);

 String attr1 = ta.getString(R.styleable.MyCustomView_custom_attr1);
 String attr2 = ta.getString(R.styleable.MyCustomView_custom_attr2);
 String attr3 = ta.getString(R.styleable.MyCustomView_custom_attr3);
 String attr4 = ta.getString(R.styleable.MyCustomView_custom_attr4);

 Log.e("customview", "attr1=" + attr1);
 Log.e("customview", "attr2=" + attr2);
 Log.e("customview", "attr3=" + attr3);
 Log.e("customview", "attr4=" + attr4);
 ta.recycle();
 }

public final TypedArray obtainStyledAttributes(AttributeSet set, @StyleableRes int[] attrs) {
 return getTheme().obtainStyledAttributes(set, attrs, 0, 0);
}

public TypedArray obtainStyledAttributes(AttributeSet set,
  @StyleableRes int[] attrs, @AttrRes int defStyleAttr, @StyleRes int defStyleRes) {
 final int len = attrs.length;
 final TypedArray array = TypedArray.obtain(Resources.this, len);

 // XXX note that for now we only work with compiled XML files.
 // To support generic XML files we will need to manually parse
 // out the attributes from the XML file (applying type information
 // contained in the resources and such).
 final XmlBlock.Parser parser = (XmlBlock.Parser)set;
 AssetManager.applyStyle(mTheme, defStyleAttr, defStyleRes,
   parser != null ? parser.mParseState : 0, attrs, array.mData, array.mIndices);

 array.mTheme = this;
 array.mXml = parser;

 if (false) {
  int[] data = array.mData;

  System.out.println("Attributes:");
  String s = " Attrs:";
  int i;
  for (i=0; i<set.getAttributeCount(); i++) {
   s = s + " " + set.getAttributeName(i);
   int id = set.getAttributeNameResource(i);
   if (id != 0) {
    s = s + "(0x" + Integer.toHexString(id) + ")";
   }
   s = s + "=" + set.getAttributeValue(i);
  }
  System.out.println(s);
  s = " Found:";
  TypedValue value = new TypedValue();
  for (i=0; i<attrs.length; i++) {
   int d = i*AssetManager.STYLE_NUM_ENTRIES;
   value.type = data[d+AssetManager.STYLE_TYPE];
   value.data = data[d+AssetManager.STYLE_DATA];
   value.assetCookie = data[d+AssetManager.STYLE_ASSET_COOKIE];
   value.resourceId = data[d+AssetManager.STYLE_RESOURCE_ID];
   s = s + " 0x" + Integer.toHexString(attrs[i])
    + "=" + value;
  }
  System.out.println(s);
 }

 return array;
}

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:custom="http://schemas.android.com/apk/res-auto"
 android:id="@+id/container"
 android:layout_width="match_parent"
 android:layout_height="match_parent">

 <com.kevintan.eventbussample.view.MyCustomView
  android:id="@+id/id_custom_view"
  android:layout_width="400dp"
  android:layout_height="400dp"
  custom:custom_attr1="attr1_xml"
  style="@style/TestCustomView"/>

</FrameLayout>

<style name="TestCustomView">
 <item name="custom_attr1">attr1_style</item>
 <item name="custom_attr2">attr2_style</item>
</style>

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:custom="http://schemas.android.com/apk/res-auto"
 android:id="@+id/container"
 android:layout_width="match_parent"
 android:layout_height="match_parent">

 <com.kevintan.eventbussample.view.MyCustomView
  android:id="@+id/id_custom_view"
  android:layout_width="400dp"
  android:layout_height="400dp"
  custom:custom_attr1="attr1_xml"
  style="@style/TestCustomView"/>

</FrameLayout>

<activity>
 android:name="com.kevintan.eventbussample.MainActivity"
 android:theme="@style/AppTheme"
 android:label="@string/app_name" >
 <intent-filter>
  <action android:name="android.intent.action.MAIN" />
  <category android:name="android.intent.category.LAUNCHER" />
 </intent-filter>
</activity>

<style name="AppTheme" parent="android:Theme.Holo.Light.DarkActionBar">
 <!-- Customize your theme here. -->
 <item name="MyCustomViewDefStyleAttr">@style/MyCustomViewDefStyleAttrImpl</item>
</style>

<style name="MyCustomViewDefStyleAttrImpl">
 <item name="custom_attr1">attr1_defStyleAttr</item>
 <item name="custom_attr2">attr2_defStyleAttr</item>
 <item name="custom_attr3">attr3_defStyleAttr</item>
</style>

public MyCustomView(Context context, AttributeSet attrs) {
 // 为defStyleAttr进行赋值
 this(context, attrs, R.attr.MyCustomViewDefStyleAttr);
}

public MyCustomView(Context context, AttributeSet attrs, int defStyleAttr) {
 super(context, attrs, defStyleAttr);

 TypedArray ta = context.getTheme().obtainStyledAttributes(attrs, R.styleable.MyCustomView, defStyleAttr, 0);

 String attr1 = ta.getString(R.styleable.MyCustomView_custom_attr1);
 String attr2 = ta.getString(R.styleable.MyCustomView_custom_attr2);
 String attr3 = ta.getString(R.styleable.MyCustomView_custom_attr3);
 String attr4 = ta.getString(R.styleable.MyCustomView_custom_attr4);

 Log.e("customview", "attr1=" + attr1);
 Log.e("customview", "attr2=" + attr2);
 Log.e("customview", "attr3=" + attr3);
 Log.e("customview", "attr4=" + attr4);
 ta.recycle();
}

<style name="MyCustomViewDefStyleRes">
 <item name="custom_attr1">attr1_defStyleRes</item>
 <item name="custom_attr2">attr2_defStyleRes</item>
 <item name="custom_attr3">attr3_defStyleRes</item>
 <item name="custom_attr4">attr4_defStyleRes</item>
</style>

public MyCustomView(Context context, AttributeSet attrs) {
 this(context, attrs, R.attr.MyCustomViewDefStyleAttr);
}

public MyCustomView(Context context, AttributeSet attrs, int defStyleAttr) {
 super(context, attrs, defStyleAttr);

 // 为defStyleRes进行赋值
 TypedArray ta = context.getTheme().obtainStyledAttributes(attrs, R.styleable.MyCustomView, defStyleAttr, R.style.MyCustomViewDefStyleRes);

 String attr1 = ta.getString(R.styleable.MyCustomView_custom_attr1);
 String attr2 = ta.getString(R.styleable.MyCustomView_custom_attr2);
 String attr3 = ta.getString(R.styleable.MyCustomView_custom_attr3);
 String attr4 = ta.getString(R.styleable.MyCustomView_custom_attr4);

 Log.e("customview", "attr1=" + attr1);
 Log.e("customview", "attr2=" + attr2);
 Log.e("customview", "attr3=" + attr3);
 Log.e("customview", "attr4=" + attr4);
 ta.recycle();
}

public MyCustomView(Context context, AttributeSet attrs) {
 // 为了验证defStyleRes的作用,将defStyleAttr设置为0
 this(context, attrs, 0);
}

public MyCustomView(Context context, AttributeSet attrs, int defStyleAttr) {
 super(context, attrs, defStyleAttr);

 TypedArray ta = context.getTheme().obtainStyledAttributes(attrs, R.styleable.MyCustomView, defStyleAttr, R.style.MyCustomViewDefStyleRes);

 String attr1 = ta.getString(R.styleable.MyCustomView_custom_attr1);
 String attr2 = ta.getString(R.styleable.MyCustomView_custom_attr2);
 String attr3 = ta.getString(R.styleable.MyCustomView_custom_attr3);
 String attr4 = ta.getString(R.styleable.MyCustomView_custom_attr4);

 Log.e("customview", "attr1=" + attr1);
 Log.e("customview", "attr2=" + attr2);
 Log.e("customview", "attr3=" + attr3);
 Log.e("customview", "attr4=" + attr4);
 ta.recycle();
}