自定义控件（转）

转自：http://www.jb51.net/article/32172.htm

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。

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

7. string：字符串。

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

8. fraction：百分数。

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

9. enum：枚举值。

<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。

<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。

<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 ：

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

public class MainActivity extends Activity implements CustomListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_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;
        }
    }

}

自定义控件（转）