android 自定义组合控件 顶部导航栏

    在软件开发过程中，经常见到，就是APP 的标题栏样式几乎都是一样的，只是文字不同而已，两边图标不同。为了减少重复代码，提高效率， 方便大家使用，我们把标题栏通过组合的方式定义成一个控件。

例下图：                                                                                                  

点击：

如不设置左边，右边图片：

下面说一下具体实现步骤：

步骤一：

导航栏包括:
* 返回按钮
* 标题
* 右侧按钮(功能不确定)

首先是布局文件,如下:

</pre><p></p><pre name="code" class="java"><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@android:color/holo_blue_light"
    tools:context=".MainActivity" >

    <TextView
        android:id="@+id/text_title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:textSize="25sp"
        android:gravity="center"
        android:textColor="@android:color/white"
        android:padding="2dp"
         />

    <ImageView
        android:id="@+id/back_image"
        android:layout_width="40dp"
        android:layout_height="40dp"
        android:scaleType="centerInside"
        android:layout_alignParentLeft="true"
        android:layout_centerVertical="true"
        android:layout_marginLeft="12dp"
          />

    <ImageView
        android:id="@+id/right_image"
        android:layout_width="40dp"
        android:layout_height="40dp"
        android:scaleType="centerInside"
        android:layout_alignParentRight="true"
        android:layout_centerVertical="true"
        android:layout_marginRight="12dp"
        />

</RelativeLayout>

步骤二：在values下新建 attrs文件 定义控件要用到的属性，如下面的代码所示。这里我们定义了标题栏文字（textText），字体大小（textSize），字体颜色（textColor），左边按钮 （leftBtn ），右边按钮 （rightBtn ）  。（当然你还要以给它添加其它属性如背景）

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="Topbar">
        <attr name="titleText" format="string|reference" />
        <attr name="titleSize" format="dimension|reference" />
        <attr name="titleColor" format="color|reference" />
        
        <attr name="leftBtn" format="reference"/>
        <attr name="rightBtn" format=" reference"/>
       
    </declare-styleable>
</resources>

步骤三：定义类Topbar继承自RelativeLayout，重写构造函数并构造方法中获得我们自定义的属性，具体代码如下。代码中定义了一个TextView显示标题文字，一个Imageview 显示左侧按钮，一个Imageview 显示右侧按钮 ，其他字段对应attrs中声明的属性。

	private ImageView backView;
    private ImageView rightView;
    private TextView titleView;

    private String titleTextStr; 
    private int titleTextSize ;
    private int  titleTextColor ;
 
    private Drawable leftImage ;
    private Drawable rightImage ;
    
    public TopBarView(Context context){
        this(context, null);
    }


    public TopBarView(Context context, AttributeSet attrs) {
        this(context, attrs,R.style.AppTheme);
        

    }

    public TopBarView(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
		getConfig(context, attrs);  
        initView(context);
	}
    
    /** 
     * 从xml中获取配置信息 
     */ 
    private void getConfig(Context context, AttributeSet attrs) {
        //TypedArray是一个数组容器用于存放属性值  
        TypedArray ta = context.obtainStyledAttributes(attrs,R.styleable.Topbar);  
         
        int count = ta.getIndexCount();
        for(int i = 0;i<count;i++)
        {
            int attr = ta.getIndex(i);  
            switch (attr)  
            {  
            case R.styleable.Topbar_titleText:  
            	titleTextStr = ta.getString(R.styleable.Topbar_titleText);    
                break;  
            case R.styleable.Topbar_titleColor:  
                // 默认颜色设置为黑色  
            	titleTextColor = ta.getColor(attr, Color.BLACK);  
                break;  
            case R.styleable.Topbar_titleSize:  
                // 默认设置为16sp，TypeValue也可以把sp转化为px  
                titleTextSize = ta.getDimensionPixelSize(attr, (int) TypedValue.applyDimension(  
                        TypedValue.COMPLEX_UNIT_SP, 16, getResources().getDisplayMetrics()));  
                break;  
  
            case R.styleable.Topbar_leftBtn:  
        
            	leftImage = ta.getDrawable(R.styleable.Topbar_leftBtn);  
                break; 
            case R.styleable.Topbar_rightBtn:  
            	rightImage = ta.getDrawable(R.styleable.Topbar_rightBtn); 
                break; 
            } 
        }

        //用完务必回收容器  
        ta.recycle(); 
		
	}


	private void initView(Context context)
    {
		View layout = LayoutInflater.from(context).inflate(R.layout.custom_groupwidget, 
				this,true);
        
        backView = (ImageView) layout.findViewById(R.id.back_image);
        titleView = (TextView) layout.findViewById(R.id.text_title);
        rightView = (ImageView) layout.findViewById(R.id.right_image);
        backView.setOnClickListener(this);
        rightView.setOnClickListener(this);
        
        if(null != leftImage)
        backView.setImageDrawable(leftImage);
        if(null != rightImage)
        rightView.setImageDrawable(rightImage);
        if(null != titleTextStr)
        {
        	titleView.setText(titleTextStr);
        	titleView.setTextSize(titleTextSize);
        	titleView.setTextColor(titleTextColor);
        }
    }

步骤四：定义了一个OnClickListenner来监听ImageView的点击

   private onTitleBarClickListener onMyClickListener;
    
    /**
     * 设置按钮点击监听接口
     * @param callback
     */
    public void setClickListener(onTitleBarClickListener listener) {
        this.onMyClickListener = listener;
    }

    /**
     * 导航栏点击监听接口
     */
    public static interface onTitleBarClickListener{
        /**
         * 点击返回按钮回调
         */
        void onBackClick();

        void onRightClick();
    }

	@Override
	public void onClick(View v) {
	 int id = v.getId();
	 switch(id)
	 {
	 case R.id.back_image:
		 if(null != onMyClickListener)
		 onMyClickListener.onBackClick();
		 break;
	 case R.id.right_image:
		 if(null != onMyClickListener)
		 onMyClickListener.onRightClick();
		 break;
	 }	
	}

步骤五： 再看一下主布局怎样使用自定义控件：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:custom="http://schemas.android.com/apk/res/com.example.customgroupwidget"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

    <com.example.customgroupwidget.TopBarView
        android:id="@+id/topbar"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        custom:titleText="我的消息" 
        custom:titleSize="15sp" 
        custom:titleColor="@android:color/white" 
        custom:leftBtn="@drawable/back_page" 
        custom:rightBtn="@drawable/edit_normal" />

</RelativeLayout>

步骤六：最后看一下Activity中的调用：

public class MainActivity extends Activity implements onTitleBarClickListener {

    private  TopBarView topbar;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        topbar = (TopBarView)findViewById(R.id.topbar);
        
        topbar.setClickListener(this);
    }
    @Override
    public void onBackClick() {
         Toast.makeText(MainActivity.this, "你点击了左侧按钮", Toast.LENGTH_LONG).show();
        
    }
    @Override
    public void onRightClick() {
        Toast.makeText(MainActivity.this, "你点击了右侧按钮", Toast.LENGTH_SHORT).show();
        
    }
}

 demo下载

最后普及一下，attrs.xml中的属性的format（类型）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>

特别要注意：

     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"

                     />