自定义控件之TopBar

在values文件下新建attrs.xml来添加自定义的属性;
attrs.xml

<?xml version="1.0" encoding="UTF-8"?><resources>    <declare-styleable name="TopBar">        <attr name="title" format="string"></attr>        <attr name="titleTextSize" format="dimension"></attr>        <attr name="titleColor" format="color"></attr>        <attr name="leftText" format="string"></attr>        <attr name="leftBackground" format="color|reference"></attr>        <attr name="leftTextColor" format="color"></attr>        <attr name="rightText" format="string"></attr>        <attr name="rihtBackground" format="color|reference"></attr>        <attr name="rightTextColor" format="color"></attr>    </declare-styleable></resources>

在自定义View里面将这些属性提取出来
TopBar.java

package com.example.day0112.ui.view;import com.example.day0112.R;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;public class TopBar extends RelativeLayout {    private String mTitle;    private int mTextColor;    private float mTitleTextSize;    private String mLeftText;    private int mLeftTextColor;    private Drawable mLeftBackground;    private String mRightText;    private int mRightTextColor;    private Drawable mRightBackground;    private Button mLeftButton;    private TextView mTitleView;    private Button mRightButton;    private LayoutParams mLeftParams;    private LayoutParams mTitleParams;    private LayoutParams mRightParams;    private topBarClickListener mListener;    @SuppressLint("NewApi")    public TopBar(Context context, AttributeSet attrs) {        super(context, attrs);        TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.TopBar);        mTitle = ta.getString(R.styleable.TopBar_title);        mTextColor = ta.getColor(R.styleable.TopBar_titleColor, 0);        mTitleTextSize = ta.getDimension(R.styleable.TopBar_titleTextSize, 10);//返回的是浮点        mLeftTextColor = ta.getColor(R.styleable.TopBar_leftTextColor, 0);        mLeftText = ta.getString(R.styleable.TopBar_leftText);        mLeftBackground = ta.getDrawable(R.styleable.TopBar_leftBackground);//返回的是drawable        mRightText = ta.getString(R.styleable.TopBar_rightText);        mRightTextColor = ta.getColor(R.styleable.TopBar_rightTextColor, 0);        mRightBackground = ta.getDrawable(R.styleable.TopBar_rihtBackground);        //获取完TypeArray后一般要调用recycle方法来避免重新创建的时候的错误        ta.recycle();        mLeftButton = new Button(context);        mTitleView = new TextView(context);        mRightButton = new Button(context);        //为创建的组件元素赋值        mLeftButton.setText(mLeftText);        mLeftButton.setTextColor(mLeftTextColor);        mLeftButton.setBackground(mLeftBackground);        mLeftButton.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View arg0) {                mListener.onLeftClick();            }        });        mTitleView.setText(mTitle);        mTitleView.setTextColor(mTextColor);        mTitleView.setTextSize(mTitleTextSize);        mTitleView.setGravity(Gravity.CENTER);        mRightButton.setText(mRightText);        mRightButton.setTextColor(mRightTextColor);        mRightButton.setBackground(mRightBackground);        mRightButton.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View arg0) {                mListener.onRightClick();            }        });        //为组件元素设置相应的布局元素        mLeftParams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT);        mLeftParams.addRule(RelativeLayout.ALIGN_PARENT_LEFT,TRUE);        //添加到ViewGroup        addView(mLeftButton,mLeftParams);        mTitleParams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT);        mTitleParams.addRule(RelativeLayout.CENTER_IN_PARENT,TRUE);        //添加到ViewGroup        addView(mTitleView,mTitleParams);        mRightParams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT);        mRightParams.addRule(RelativeLayout.ALIGN_PARENT_RIGHT,TRUE);//继承RelativeLayout才能这样写        //添加到ViewGroup        addView(mRightButton,mRightParams);    }    public interface topBarClickListener {        //左按钮点击事件        void onLeftClick();        //右按钮点击事件        void onRightClick();    }    public void setOnTopBarClickListener(topBarClickListener mListener) {        this.mListener = mListener;    }    /**     * 设置按钮的显示与否，通过id区分按钮，flag区分是否显示     * @param id  0:左按钮  1：右按钮     * @param flag 是否显示     */    public void setButtonVisiable(int id,boolean flag) {        if (flag) {            if (id == 0) {                mLeftButton.setVisibility(View.VISIBLE);            } else {                mRightButton.setVisibility(View.VISIBLE);            }        } else {            if (id == 0) {                mLeftButton.setVisibility(View.GONE);            } else {                mRightButton.setVisibility(View.GONE);            }        }    }}

在main_activity.xml里面引用topbar.xml
main_activity.xml

<LinearLayout     xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"     android:layout_height="match_parent"    xmlns:app="http://schemas.android.com/apk/res/com.example.day0112">   <include layout="@layout/topbar" />   <!-- 引用 --></LinearLayout>

topbar.xml

  <com.example.day0112.ui.view.TopBar         xmlns:android="http://schemas.android.com/apk/res/android"        xmlns:app="http://schemas.android.com/apk/res/com.example.day0112"        android:layout_width="match_parent"        android:layout_height="40dp"        android:background="#fff"        android:id="@+id/topBar"        app:title="自定义标题"        app:titleTextSize="6sp"        app:titleColor="#333"        app:leftText="Back"        app:leftTextColor="#333"        app:leftBackground="#fff"        app:rightText="Right"        app:rightTextColor="#333"        app:rihtBackground="#fff"      ></com.example.day0112.ui.view.TopBar>  <!-- android studio 引用第三方控件的名字空间 --> <!-- xmlns:custom="http://schemas.android.com/apk/res/res-auto" --> <!-- eclipse 引用第三方控件的名字空间 --> <!-- xmlns:app="http://schemas.android.com/apk/res/com.example.day0112" --><!-- xmlns:app="http://schemas.android.com/apk/res/包名" -->

具体用法
MainActivity.java

package com.example.day0112;import com.example.day0112.ui.view.TopBar;import com.example.day0112.ui.view.TopBar.topBarClickListener;import android.os.Bundle;import android.app.Activity;import android.view.Menu;import android.widget.TextView;import android.widget.Toast;public class MainActivity extends Activity{    private TopBar topBar;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        topBar = (TopBar) findViewById(R.id.topBar);        topBar.setOnTopBarClickListener(new topBarClickListener() {            @Override            public void onRightClick() {                Toast.makeText(getApplicationContext(), "click right", Toast.LENGTH_LONG).show();            }            @Override            public void onLeftClick() {                Toast.makeText(getApplicationContext(), "click left", Toast.LENGTH_LONG).show();            }        });    }}

效果：

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代码摘自–Android群英传