Android 创办自定义View 实现TopBar

在Android 应用开发中常常使用到自定义，我想自定义一个TopBar（左右两边分别是一个Button 中间是一个TextView ） 定义方法

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1.首先增加自定义属性，创建一个 attrs.xml文件，分别定义了以下需要使用的属性

<?xml version="1.0" encoding="utf-8"?><resources>    <declare-styleable name="Topbar" >        <attr name="title" format="string" />        <attr name="titleTextSize" format="dimension" />        <attr name="titleColor" format="color" />        <attr name="leftText" format="string" />        <attr name="leftTextColor" format="color" />        <attr name="leftBackground" format="reference|color"/>        <attr name="RightText" format="string" />        <attr name="RightTextColor" format="color" />        <attr name="RightBackground" format="reference|color"/>      </declare-styleable>    </resources>

?2.实现一个自定义View 对象TopBar.java 继承ReleativeLayout

package com.test.customview;import android.annotation.SuppressLint;import android.content.Context;import android.content.res.TypedArray;import android.graphics.drawable.Drawable;import android.util.AttributeSet;import android.view.Gravity;import android.view.View;import android.widget.Button;import android.widget.RelativeLayout;import android.widget.TextView;@SuppressLint("NewApi")public class TopBar extends RelativeLayout{		/**	 * 创建的自定义属性	 */	private TextView mTitleText;	private Button mLeftBtn;	private Button mRightBtn;		private String mTitle;	private int  mTitleColor;	private float  mTitleTextSize;		private String mLeftText;	private Drawable mleftBackgound;	private int mLeftTextColor;		private String mRightText;	private Drawable mRightBackgound;	private int mRightTextColor;		private LayoutParams mLeftParams,mRightParams,mTitleParams;	private OnclickListener listener;		/**	 * 定义一个点击事件的回调接口	 * @author acer	 *	 */	public interface OnclickListener{		public void leftListener();		public void rightListener();	}		/**	 * 设置点击事件接口回调	 * @param listener	 */	public void setOnclickListener(OnclickListener listener){		this.listener = listener;	}	public TopBar(Context context, AttributeSet attrs) {		super(context, attrs);		TypedArray ta = context.obtainStyledAttributes(attrs,R.styleable.Topbar);				//获取在attrs.xml中自定义的属性值		mTitle = ta.getString(R.styleable.Topbar_title);		mTitleColor = ta.getColor(R.styleable.Topbar_titleColor, 0);		mTitleTextSize = ta.getDimension(R.styleable.Topbar_titleTextSize, 0);				mLeftText = ta.getString(R.styleable.Topbar_leftText);		mLeftTextColor = ta.getColor(R.styleable.Topbar_leftTextColor, 0);		mleftBackgound = ta.getDrawable(R.styleable.Topbar_leftBackground);				mRightBackgound = ta.getDrawable(R.styleable.Topbar_RightBackground);		mRightText = ta.getString(R.styleable.Topbar_RightText);		mRightTextColor = ta.getInt(R.styleable.Topbar_RightTextColor, 0);				ta.recycle();				mTitleText = new TextView(context);		mLeftBtn = new Button(context);		mRightBtn = new Button(context);				mTitleText.setText(mTitle);		mTitleText.setBackgroundColor(mTitleColor);		mTitleText.setTextSize(mTitleTextSize);		mTitleText.setGravity(Gravity.CENTER);				mLeftBtn.setBackground(mleftBackgound);		mLeftBtn.setText(mLeftText);		mLeftBtn.setTextColor(mLeftTextColor);				mRightBtn.setBackground(mRightBackgound);		mRightBtn.setText(mRightText);		mRightBtn.setTextColor(mRightTextColor);				setBackgroundColor(0xFF58543);				//设置控件的参数值		mLeftParams = new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);		mLeftParams.addRule(ALIGN_PARENT_LEFT,TRUE);		mRightParams = new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);		mRightParams.addRule(ALIGN_PARENT_RIGHT,TRUE);		mTitleParams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.FILL_PARENT);		mTitleParams.addRule(CENTER_IN_PARENT, TRUE);		//将定义的 控件键加入到ReleativeLayout中		addView(mLeftBtn, mLeftParams);		addView(mRightBtn,mRightParams);		addView(mTitleText,mTitleParams);				mLeftBtn.setOnClickListener(new OnClickListener() {						@Override			public void onClick(View v) {				//回调onclick事件传给显示层处理不同的逻辑				listener.leftListener();			}		});				mRightBtn.setOnClickListener(new OnClickListener() {						@Override			public void onClick(View v) {				listener.rightListener();			}		});	}}

?3.在xml文件中引入定义好的控件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:custom="http://schemas.android.com/apk/res/com.test.customview"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent">    <com.test.customview.TopBar        android:id="@+id/topbar"        android:layout_width="match_parent"        android:layout_height="35dp"        custom:title="标题"        custom:titleTextSize="10sp"        custom:titleColor="#FFFFFF"        custom:leftText="back"        custom:leftTextColor="#FFFFFF"        custom:leftBackground="@drawable/ic_launcher"        custom:RightText="more"        custom:RightTextColor="#FFFFFF"        custom:RightBackground="@drawable/ic_launcher"        >    </com.test.customview.TopBar>    </RelativeLayout>

?4.在Activity 中加入该布局文件，并处理相关点击事件

package com.test.customview;import com.test.customview.TopBar.OnclickListener;import android.app.Activity;import android.os.Bundle;import android.view.Menu;import android.view.MenuItem;import android.widget.Toast;public class MainActivity extends Activity {	@Override	protected void onCreate(Bundle savedInstanceState) {		super.onCreate(savedInstanceState);		setContentView(R.layout.activity_main);		TopBar  topBar = (TopBar) findViewById(R.id.topbar);		//这里处理Button的点击事件		topBar.setOnclickListener(new OnclickListener() {						@Override			public void rightListener() {				Toast.makeText(MainActivity.this, "click left button", Toast.LENGTH_LONG).show();			}						@Override			public void leftListener() {				Toast.makeText(MainActivity.this, "click right button", Toast.LENGTH_LONG).show();			}		});	}}

?自此一个TopBar 的自定义控件完成，在不同的Activity布局中直接使用即可。