android 自定义控件 自定义属性详细介绍

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> 

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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; } } }