android 自定义属性详解

今天用到了自定义控件，也想用一下自定义属性，从网上搜了一下资料汇总的一下。

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"

                     />

 在xml 文件里定义控件的属性，我们已经习惯了android:attrs="" ,那么我们能不能定义自己的属性能，比如:test:attrs="" 呢？答案是肯定的.

        好了我就不卖关子了，直接进入主题。大致以下步骤:
        一、 在res/values 文件下定义一个attrs.xml 文件.代码如下:

<?xml version="1.0" encoding="utf-8"?> 
<resources> 
<declare-styleable name="MyView"> 
<attr name="textColor" format="color" /> 
<attr name="textSize" format="dimension" /> 
</declare-styleable> 
</resources> 

二、 我们在MyView.java 代码修改如下，其中下面的构造方法是重点，我们获取定义的属性我们R.sytleable.MyView_textColor, 获取方法中后面通常设定默认值(float textSize = a.getDimension(R.styleable.MyView_textSize, 36 ); )， 防止我们在xml 文件中没有定义.从而使用默认值!

        获取，MyView 就是定义在<declare-styleable name="MyView "></declare-styleable> 里的名字,获取里面属性用名字_ 属性 连接起来就可以.TypedArray 通常最后调用 .recycle() 方法，为了保持以后使用该属性一致性！

public MyView(Context context,AttributeSet attrs) 
{ 
super(context,attrs); 
mPaint = new Paint(); 
TypedArray a = context.obtainStyledAttributes(attrs,R.styleable.MyView); 
int textColor = a.getColor(R.styleable.MyView_textColor, 0XFFFFFFFF); 
float textSize = a.getDimension(R.styleable.MyView_textSize, 36); 
mPaint.setTextSize(textSize); 
mPaint.setColor(textColor); 
a.recycle(); 
} 

MyView.java 全部代码如下:

package eoe.demo; 


import android.content.Context; 
import android.content.res.TypedArray; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Paint; 
import android.graphics.Rect; 
import android.graphics.Paint.Style; 
import android.util.AttributeSet; 
import android.view.View; 


public class MyView extends View { 
private Paint mPaint; 
private Context mContext; 
private static final String mString = "Welcome to Mr Wei's blog"; 
public MyView(Context context) { 
super(context); 
mPaint = new Paint(); 
} 
public MyView(Context context,AttributeSet attrs) 
{ 
super(context,attrs); 
mPaint = new Paint(); 
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.MyView); 
int textColor = a.getColor(R.styleable.MyView_textColor,0XFFFFFFFF); 
float textSize = a.getDimension(R.styleable.MyView_textSize, 36); 
mPaint.setTextSize(textSize); 
mPaint.setColor(textColor); 
a.recycle(); 
} 


@Override 
protected void onDraw(Canvas canvas) { 
// TODO Auto-generated method stub 
super.onDraw(canvas); 
//设置填充 
mPaint.setStyle(Style.FILL); 
//画一个矩形,前俩个是矩形左上角坐标，后面俩个是右下角坐标 
canvas.drawRect(new Rect(10, 10, 100, 100), mPaint); 
mPaint.setColor(Color.BLUE); 
//绘制文字 
canvas.drawText(mString, 10, 110, mPaint); 
} 
} 

   将我们自定义的MyView 加入布局main.xml 文件中，平且使用自定义属性,自定义属性必须加上:
xmlns:test ="http://schemas.android.com/apk/res/com.android.tutor "蓝色 是自定义属性的前缀，红色是我们包名.

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout 
xmlns:android="http://schemas.android.com/apk/res/android" 

xmlns:test="http://schemas.android.com/apk/res/com.android.tutor" 
android:orientation="vertical" 
android:layout_width="fill_parent" 
android:layout_height="fill_parent" 
> 


<TextView 
android:layout_width="fill_parent" 
android:layout_height="wrap_content" 
android:text="@string/hello" 
/> 


<com.android.tutor.MyView 
android:layout_width="fill_parent" 
android:layout_height="fill_parent" 
test:textSize="20px" 
test:textColor="#fff" 
/> 
</LinearLayout>