自定义控件之二 attr属性值

自定义控件在android中无处不见，自定义控件给了我们很大的方便。比如说，一个视图为imageview  ，imagebutton ,textview 等诸多控件的组合，用的地方有很多，我们不可能每次都来写3个的组合，既浪费时间，效率又低。在这种情况下，我们就可以自定义一个view来替换他们，不仅提升了效率并且在xml中运用也是相当的美观。

一、控件自定义属性介绍

以下示例中代码均在values/attrs.xml 中定义，属性均可随意命名。

1. reference：参考某一资源ID。

示例：

 <declare-styleable name = "名称">
        <attr name = "background" format = "reference" />
        <attr name = "src" format = "reference" />
 </declare-styleable>

2. color：颜色值。
示例：

 <declare-styleable name = "名称">
        <attr name = "textColor" format = "color" />
 </declare-styleable>

3. boolean：布尔值。
示例：

 <declare-styleable name = "名称">
        <attr name = "focusable" format = "boolean" />
 </declare-styleable>

4. dimension：尺寸值。
示例：

 <declare-styleable name = "名称">
        <attr name = "layout_width" format = "dimension" />
 </declare-styleable>

5. float：浮点值。
示例：

 <declare-styleable name = "名称">
        <attr name = "fromAlpha" format = "float" />
        <attr name = "toAlpha" format = "float" />
 </declare-styleable>

6. integer：整型值。
示例：

 <declare-styleable name = "名称">
        <attr name = "frameDuration" format="integer" />
        <attr name = "framesCount" format="integer" />
 </declare-styleable>

7. string：字符串。
示例：

 <declare-styleable name = "名称">
        <attr name = "text" format = "string" />
 </declare-styleable>

8. fraction：百分数。
示例：

 <declare-styleable name="名称">
        <attr name = "pivotX" format = "fraction" />
        <attr name = "pivotY" format = "fraction" />
 </declare-styleable>

9. enum：枚举值。
示例：

 <declare-styleable name="名称">
        <attr name="orientation">
               <enum name="horizontal" value="0" />
               <enum name="vertical" value="1" />
        </attr>
 </declare-styleable>

10. flag：位或运算。

示例：

 <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" />
         </attr>
 </declare-styleable>

11.多类型。
示例：

 <declare-styleable name = "名称">
        <attr name = "background" format = "reference|color" />
 </declare-styleable>

-------------------------------------------------------------------------------------------

二、属性的使用以及自定义控件的实现

1、构思控件的组成元素，思考所需自定义的属性。

       比如：我要做一个  <带阴影的按钮，按钮正下方有文字说明>（类似9宫格按钮） 

       新建values/attrs.xml

 <?xml version="1.0" encoding="utf-8"?>
 <resources>
     <declare-styleable name="custom_view">
         <attr name="custom_id" format="integer" />
         <attr name="src" format="reference" />
         <attr name="background" format="reference" />
         <attr name="text" format="string" />
         <attr name="textColor" format="color" />
         <attr name="textSize" format="dimension" />
     </declare-styleable>
 </resources>

       以上，所定义为custom_view，custom_id为按钮id，src为按钮，background为阴影背景，text为按钮说明，textColor为字体颜色，textSize为字体大小。

2、怎么自定义控件呢，怎么使用这些属性呢？话不多说请看代码，CustomView ：

 package com.nanlus.custom;

 import com.nanlus.custom.R;
 import android.content.Context;
 import android.content.res.TypedArray;
 import android.graphics.Color;
 import android.graphics.drawable.Drawable;
 import android.util.AttributeSet;
 import android.view.Gravity;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.FrameLayout;
 import android.widget.ImageButton;
 import android.widget.ImageView;
 import android.widget.TextView;
 public class CustomView extends FrameLayout implements OnClickListener {

     private CustomListener customListener = null;

     private Drawable mSrc = null, mBackground = null;
     private String mText = "";
     private int mTextColor = 0;
     private float mTextSize = 20;
     private int mCustomId = 0;

     private ImageView mBackgroundView = null;
     private ImageButton mButtonView = null;
     private TextView mTextView = null;

     private LayoutParams mParams = null;

     public CustomView(Context context) {
         super(context);

     }

     public CustomView(Context context, AttributeSet attrs) {
         super(context, attrs);

         TypedArray a = context.obtainStyledAttributes(attrs,
                 R.styleable.custom_view);

         mSrc = a.getDrawable(R.styleable.custom_view_src);
         mBackground = a.getDrawable(R.styleable.custom_view_background);
         mText = a.getString(R.styleable.custom_view_text);
         mTextColor = a.getColor(R.styleable.custom_view_textColor,
                 Color.WHITE);
         mTextSize = a.getDimension(R.styleable.custom_view_textSize, 20);
         mCustomId = a.getInt(R.styleable.custom_view_custom_id, 0);

         mTextView = new TextView(context);
         mTextView.setTextSize(mTextSize);
         mTextView.setTextColor(mTextColor);
         mTextView.setText(mText);
         mTextView.setGravity(Gravity.CENTER);
         mTextView.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,
                 LayoutParams.WRAP_CONTENT));

         mButtonView = new ImageButton(context);
         mButtonView.setImageDrawable(mSrc);
         mButtonView.setBackgroundDrawable(null);
         mButtonView.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,
                 LayoutParams.WRAP_CONTENT));
         mButtonView.setOnClickListener(this);

         mBackgroundView = new ImageView(context);
         mBackgroundView.setImageDrawable(mBackground);
         mBackgroundView.setLayoutParams(new LayoutParams(
                 LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));

         addView(mBackgroundView);
         addView(mButtonView);
         addView(mTextView);

         this.setOnClickListener(this);

         a.recycle();
     }

     @Override
     protected void onAttachedToWindow() {
         super.onAttachedToWindow();

         mParams = (LayoutParams) mButtonView.getLayoutParams();
         if (mParams != null) {
             mParams.gravity = Gravity.CENTER_HORIZONTAL | Gravity.TOP;
             mButtonView.setLayoutParams(mParams);
         }

         mParams = (LayoutParams) mBackgroundView.getLayoutParams();
         if (mParams != null) {
             mParams.gravity = Gravity.CENTER_HORIZONTAL | Gravity.TOP;
             mBackgroundView.setLayoutParams(mParams);
         }

         mParams = (LayoutParams) mTextView.getLayoutParams();
         if (mParams != null) {
             mParams.gravity = Gravity.CENTER_HORIZONTAL | Gravity.BOTTOM;
             mTextView.setLayoutParams(mParams);
         }
     }

     public void setCustomListener(CustomListener l) {
         customListener = l;
     }

     @Override
     public void onClick(View v) {
         if (customListener != null) {
             customListener.onCuscomClick(v, mCustomId);
         }
     }

     public interface CustomListener {
         void onCuscomClick(View v, int custom_id);
     }
 }

代码很简单，就不多说，下面来看看我们的CustomView是怎么用的，请看：

 
3、自定义控件的使用

      话不多说，请看代码，main.xml：

 <?xml version="1.0" encoding="utf-8"?>
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:nanlus="http://schemas.android.com/apk/res/com.nanlus.custom"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent" >

     <LinearLayout
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_centerHorizontal="true"
          android:layout_centerVertical="true"
         android:orientation="horizontal" >

         <com.nanlus.custom.CustomView
             android:id="@+id/custom1"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_weight="1"
             nanlus:background="@drawable/background"
             nanlus:custom_id="1"
             nanlus:src="@drawable/style_button"
             nanlus:text="按钮1" >
         </com.nanlus.custom.CustomView>
     </LinearLayout>


 </RelativeLayout>

在这里需要解释一下，

xmlns:nanlus="http://schemas.android.com/apk/res/com.nanlus.custom"

nanlus为在xml中的前缀，com.nanlus.custom为包名

4、在Activity中，直接上代码

 package com.nanlus.custom;

 import android.os.Bundle;
 import android.view.View;
 import android.widget.ImageButton;
 import android.widget.ImageView;
 import android.widget.TextView;
 import android.widget.Toast;
 import com.nanlus.BaseActivity;
 import com.nanlus.custom.R;
 import com.nanlus.custom.CustomView.CustomListener;

 public class CustomActivity extends BaseActivity implements CustomListener {

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);

         setContentView(R.layout.main);

         ((CustomView) this.findViewById(R.id.custom1)).setCustomListener(this);
     }

     @Override
     public void onCuscomClick(View v, int custom_id) {
         switch (custom_id) {
         case 1:
             Toast.makeText(this, "hello !!!", Toast.LENGTH_LONG).show();
             break;
         default:
             break;
         }

     }

 }