Android 自定义View时使用TypedArray配置样式属性详细介绍

/**  * @title ExpandTextView  * @description 可扩展TextView，可以通过设置ExpandTextViewStyle来自定义展开图片、收起图片和最小展示的行数  */ public class ExpandTextView extends LinearLayout implements OnClickListener {   /**    * 默认最少展示的行数    */   private int defaultMinLines;   /**    * 是否展开    */   private boolean mCollapsed = true;   /**    * 是否重新布局    */   private boolean mRelayout = false;    private View expandView;   private TextView expandText;   private ImageView expandImg;   private Drawable mExpandDrawable;   private Drawable mCollapseDrawable;    public ExpandTextView(Context context) {     this(context, null);   }    public ExpandTextView(Context context, AttributeSet attrs) {     super(context, attrs);     init(attrs);   }    private void init(AttributeSet attrs) {     expandView = LayoutInflater.from(getContext()).inflate(         R.layout.pt__expand_textview, null);     expandText = (TextView) expandView.findViewById(R.id.expand_text);     expandText.setOnClickListener(this);     expandImg = (ImageView) expandView.findViewById(R.id.expand_img);     expandImg.setOnClickListener(this);      TypedArray a = getContext().obtainStyledAttributes(attrs,         R.styleable.ExpandTextViewStyle);     // 自定义图片资源     mExpandDrawable = getResources().getDrawable(         a.getResourceId(R.styleable.ExpandTextViewStyle_expand,             R.drawable.pt__ic_expand));     expandImg.setBackgroundDrawable(mExpandDrawable);     mCollapseDrawable = getResources().getDrawable(         a.getResourceId(R.styleable.ExpandTextViewStyle_collapse,             R.drawable.pt__ic_collapse));     // 自定义最小行数     defaultMinLines = a.getInt(         R.styleable.ExpandTextViewStyle_default_min_lines, 2);     a.recycle();      LinearLayout.LayoutParams params = new LayoutParams(         LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);     params.gravity = Gravity.CENTER;     addView(expandView, params);   }    @Override   protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {     if (!mRelayout) {       super.onMeasure(widthMeasureSpec, heightMeasureSpec);       return;     }     mRelayout = false;     expandText.setMaxLines(Integer.MAX_VALUE);     expandImg.setVisibility(View.GONE);     super.onMeasure(widthMeasureSpec, heightMeasureSpec);     if (expandText.getLineCount() <= defaultMinLines) {       return;     }     if (mCollapsed) {       expandText.setMaxLines(defaultMinLines);     }     expandImg.setVisibility(View.VISIBLE);     super.onMeasure(widthMeasureSpec, heightMeasureSpec);   }    public void setText(CharSequence text) {     mRelayout = true;     expandText.setText(text);   }    public void setText(int resId) {     this.setText(getContext().getString(resId));   }    @Override   public void onClick(View view) {     if (expandImg.getVisibility() != View.VISIBLE) {       return;     }     mCollapsed = !mCollapsed;     expandImg.setBackgroundDrawable(mCollapsed ? mExpandDrawable         : mCollapseDrawable);     expandText         .setMaxLines(mCollapsed ? defaultMinLines : Integer.MAX_VALUE);   } } 

<resources>    <!-- ******************************可扩展ExpandTextView样式******************************* -->   <declare-styleable name="ExpandTextViewStyle">      <!-- 展开图片 -->     <attr name="expand" format="reference" />     <!-- 关闭图片 -->     <attr name="collapse" format="reference" />     <!-- 最小行数 -->     <attr name="default_min_lines" format="integer" />   </declare-styleable>  </resources> 

<!-- 可扩展ExpandTextView样式 -->   <style name="ExpandTextViewStyle">     <item name="expand">@drawable/pt__ic_expand</item>     <item name="collapse">@drawable/pt__ic_collapse</item>     <item name="default_min_lines">3</item>   </style> 

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"   xmlns:custom="http://schemas.android.com/apk/res/com.example.typedarraytest"   android:layout_width="match_parent"   android:layout_height="match_parent"   android:paddingBottom="@dimen/activity_vertical_margin"   android:paddingLeft="@dimen/activity_horizontal_margin"   android:paddingRight="@dimen/activity_horizontal_margin"   android:paddingTop="@dimen/activity_vertical_margin" >    <com.example.typedarraytest.ExpandTextView     android:id="@+id/expand_text_view"     style="@style/ExpandTextViewStyle"     android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:layout_margin="8dp"     custom:default_min_lines="2" />  </RelativeLayout> 

TypedArray a = getContext().obtainStyledAttributes(attrs,     R.styleable.ExpandTextViewStyle); // 自定义图片资源 mExpandDrawable = getResources().getDrawable(     a.getResourceId(R.styleable.ExpandTextViewStyle_expand,         R.drawable.pt__ic_expand)); expandImg.setBackgroundDrawable(mExpandDrawable); mCollapseDrawable = getResources().getDrawable(     a.getResourceId(R.styleable.ExpandTextViewStyle_collapse,         R.drawable.pt__ic_collapse)); // 自定义最小行数 defaultMinLines = a.getInt(     R.styleable.ExpandTextViewStyle_default_min_lines, 2); a.recycle();