对于自定义属性，需要遵循以下几步，就可以实现：
- 自定义一个IcoLayout(extends View )类
- 编写values/attrs.xml，在其中编写styleable和item等标签元素
- 在布局文件中IcoLayout使用自定义的属性（注意namespace）
- 在IcoLayout的构造方法中通过TypedArray获取
一：在res/values新增一个attrs.xml文件
并写入如下内容：
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="ico_layout">
<attr name="layout_ico" format="reference"></attr>
<attr name="layout_text" format="string"></attr>
</declare-styleable>
</resources>二：在xml布局中使用
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res/com.biumall.attrs"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<!--
xmlns:app="http://schemas.android.com/apk/res/com.biumall.attrs"
xmlns:app中的app可以换成其他的比如xmlns:lys等等
后面的com.biumall.attrs是改程序的主包名，不是自定义View的包名,切记！！！！
-->
<com.biumall.view.IcoLayout
android:layout_width="587dp"
android:layout_height="53dp"
app:layout_ico="@drawable/video_bg"
app:layout_text="@string/hello_world" >
</com.biumall.view.IcoLayout>
</RelativeLayout>三：写自定义View并获取attrs中的值
package com.biumall
.view;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.drawable.BitmapDrawable;
import android.util.AttributeSet;
import android.view.View;
import com.biumall.attrs.R;
public class IcoLayout extends View {
private Bitmap icoBitmap = null;
private String icoText = null;
// 字体大小
private int textSize = 30;
// 自定位置调节
private int text_margin_left = 80;
private int text_margin_top = 37;
// 需要布局的高宽
private final int DEFAULT_WIDTH = 587;
private final int DEFAULT_HEIGHT = 52;
private Paint mPaint = null;
public IcoLayout(Context context) {
this(context, null);
}
public IcoLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public IcoLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
initUI(context, attrs);
}
private void initUI(Context context, AttributeSet attrs) {
TypedArray typedArray = context.obtainStyledAttributes(attrs,
R.styleable.ico_layout);
icoBitmap = ((BitmapDrawable) typedArray
.getDrawable(R.styleable.ico_layout_layout_ico)).getBitmap();
icoText = (String) typedArray
.getText(R.styleable.ico_layout_layout_text);
// 这句一定需要 释放资源
typedArray.recycle();
// 初始化画刷
mPaint = new Paint();
return;
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// TODO Auto-generated method stub
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int width = getMesureSize(DEFAULT_WIDTH, widthMeasureSpec);
int height = getMesureSize(DEFAULT_HEIGHT, heightMeasureSpec);
setMeasuredDimension(width, height);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
// 画ico 图片
canvas.drawBitmap(icoBitmap, 0, 0, mPaint);
// 或ico 文本
mPaint.setColor(Color.WHITE);
mPaint.setTextSize(textSize);
//这里文字居位置数据是测试的，没有可靠性！ 需要根据字体大小而调节
canvas.drawText(icoText, text_margin_left, text_margin_top, mPaint);
}
private int getMesureSize(int default_size, int measureSpec) {
int current_size = default_size;
int mode = MeasureSpec.getMode(measureSpec);
int size = MeasureSpec.getSize(measureSpec);
switch (mode) {
case MeasureSpec.AT_MOST:
current_size = size;
break;
case MeasureSpec.EXACTLY:
current_size = size;
break;
case MeasureSpec.UNSPECIFIED:
current_size = default_size;
break;
default:
break;
}
return current_size;
}
}
四：attrs内容补充说明
下面是一些关于attrs属性值的定义说明
1. reference：参考某一资源ID。
（1）属性定义：
<declare-styleable name = "名称">
<attr name = "background" format = "reference" />
</declare-styleable>
（2）属性使用：
<ImageView
android:layout_width = "42dip"
android:layout_height = "42dip"
android:background = "@drawable/图片ID"
/>
2. color：颜色值。
（1）属性定义：
<declare-styleable name = "名称">
<attr name = "textColor" format = "color" />
</declare-styleable>
（2）属性使用：
<TextView
android:layout_width = "42dip"
android:layout_height = "42dip"
android:textColor = "#00FF00"
/>
3. boolean：布尔值。
（1）属性定义：
<declare-styleable name = "名称">
<attr name = "focusable" format = "boolean" />
</declare-styleable>
（2）属性使用：
<Button
android:layout_width = "42dip"
android:layout_height = "42dip"
android:focusable = "true"
/>
4. dimension：尺寸值。
（1）属性定义：
<declare-styleable name = "名称">
<attr name = "layout_width" format = "dimension" />
</declare-styleable>
（2）属性使用：
<Button
android:layout_width = "42dip"
android:layout_height = "42dip"
/>
5. float：浮点值。
（1）属性定义：
<declare-styleable name = "AlphaAnimation">
<attr name = "fromAlpha" format = "float" />
<attr name = "toAlpha" format = "float" />
</declare-styleable>
（2）属性使用：
<alpha
android:fromAlpha = "1.0"
android:toAlpha = "0.7"
/>
6. integer：整型值。
（1）属性定义：
<declare-styleable name = "AnimatedRotateDrawable">
<attr name = "visible" />
<attr name = "frameDuration" format="integer" />
<attr name = "framesCount" format="integer" />
<attr name = "pivotX" />
<attr name = "pivotY" />
<attr name = "drawable" />
</declare-styleable>
（2）属性使用：
<animated-rotate
xmlns:android = "http://schemas.android.com/apk/res/android"
android:drawable = "@drawable/图片ID"
android:pivotX = "50%"
android:pivotY = "50%"
android:framesCount = "12"
android:frameDuration = "100"
/>
7. string：字符串。
（1）属性定义：
<declare-styleable name = "MapView">
<attr name = "apiKey" format = "string" />
</declare-styleable>
（2）属性使用：
<com.google.android.maps.MapView
android:layout_width = "fill_parent"
android:layout_height = "fill_parent"
android:apiKey = "0jOkQ80oD1JL9C6HAja99uGXCRiS2CGjKO_bc_g"
/>
8. fraction：百分数。
（1）属性定义：
<declare-styleable name="RotateDrawable">
<attr name = "visible" />
<attr name = "fromDegrees" format = "float" />
<attr name = "toDegrees" format = "float" />
<attr name = "pivotX" format = "fraction" />
<attr name = "pivotY" format = "fraction" />
<attr name = "drawable" />
</declare-styleable>
（2）属性使用：
<rotate
xmlns:android = "http://schemas.android.com/apk/res/android"
android:interpolator = "@anim/动画ID"
android:fromDegrees = "0"
android:toDegrees = "360"
android:pivotX = "200%"
android:pivotY = "300%"
android:duration = "5000"
android:repeatMode = "restart"
android:repeatCount = "infinite"
/>
9. enum：枚举值。
（1）属性定义：
<declare-styleable name="名称">
<attr name="orientation">
<enum name="horizontal" value="0" />
<enum name="vertical" value="1" />
</attr>
</declare-styleable>
（2）属性使用：
<LinearLayout
xmlns:android = "http://schemas.android.com/apk/res/android"
android:orientation = "vertical"
android:layout_width = "fill_parent"
android:layout_height = "fill_parent"
>
</LinearLayout>
10. flag：位或运算。
（1）属性定义：
<declare-styleable name="名称">
<attr name="windowSoftInputMode">
<flag name = "stateUnspecified" value = "0" />
<flag name = "stateUnchanged" value = "1" />
<flag name = "stateHidden" value = "2" />
<flag name = "stateAlwaysHidden" value = "3" />
<flag name = "stateVisible" value = "4" />
<flag name = "stateAlwaysVisible" value = "5" />
<flag name = "adjustUnspecified" value = "0x00" />
<flag name = "adjustResize" value = "0x10" />
<flag name = "adjustPan" value = "0x20" />
<flag name = "adjustNothing" value = "0x30" />
</attr>
</declare-styleable>
（2）属性使用：
<activity
android:name = ".StyleAndThemeActivity"
android:label = "@string/app_name"
android:windowSoftInputMode = "stateUnspecified | stateUnchanged | stateHidden">
<intent-filter>
<action android:name = "android.intent.action.MAIN" />
<category android:name = "android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
注意：
属性定义时可以指定多种类型值。
（1）属性定义：
<declare-styleable name = "名称">
<attr name = "background" format = "reference|color" />
</declare-styleable>
（2）属性使用：
<ImageView
android:layout_width = "42dip"
android:layout_height = "42dip"
android:background = "@drawable/图片ID|#00FF00" 本文部分内容摘抄于《Android高手进阶篇2-自定义AttributeSet属性 》和《Android 深入理解Android中的自定义属性 》
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