Android自定义View之自定义复合控件--标题栏

1 实现效果

2 例子代码讲解

2.1 attrs.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <declare-styleable name="TopBar">
        <attr name="title" format="string" />
        <attr name="titleTextSize" format="dimension" />
        <attr name="titleTextColor" format="color" />

        <attr name="leftTextColor" format="color" />
        <attr name="leftBackground" format="reference|color" />
        <attr name="leftText" format="string" />

        <attr name="rightTextColor" format="color" />
        <attr name="rightBackground" format="reference|color" />
        <attr name="rightText" format="string" />
    </declare-styleable>

</resources>

2.2 topbar.xml

<com.xys.mytopbar.Topbar xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:custom="http://schemas.android.com/apk/res-auto"
    android:id="@+id/topBar"
    android:layout_width="match_parent"
    android:layout_height="40dp"

    custom:leftBackground="@drawable/blue_button"
    custom:leftText="Back"
    custom:leftTextColor="#FFFFFF"

    custom:rightBackground="@drawable/blue_button"
    custom:rightText="More"
    custom:rightTextColor="#FFFFFF"

    custom:title="自定义标题"
    custom:titleTextColor="#123412"
    custom:titleTextSize="15sp">

</com.xys.mytopbar.Topbar>

2.3 TopBar.java

package com.imooc.systemwidget;

public class TopBar extends RelativeLayout {

    // 包含topbar上的元素：左按钮、右按钮、标题
    private Button mLeftButton, mRightButton;
    private TextView mTitleView;
    // 布局属性，用来控制组件元素在ViewGroup中的位置
    private LayoutParams mLeftParams, mTitlepParams, mRightParams;

    // 左按钮的属性值，即我们在atts.xml文件中定义的属性
    private int mLeftTextColor;
    private Drawable mLeftBackground;
    private String mLeftText;
    // 右按钮的属性值
    private int mRightTextColor;
    private Drawable mRightBackground;
    private String mRightText;
    // 标题的属性值
    private float mTitleTextSize;
    private int mTitleTextColor;
    private String mTitle;

    public TopBar(Context context) {
        super(context);
    }

    public TopBar(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    public TopBar(Context context, AttributeSet attrs) {
        super(context, attrs);
        // 设置topbar的背景
        setBackgroundColor(0xFFF59563);

        // 1.1 通过这个方法，将你在atts.xml中定义的declare-styleable的所有属性的值存储到TypedArray中
        TypedArray ta = context.obtainStyledAttributes(attrs,
                R.styleable.TopBar);
        // 1.2 从TypedArray中取出对应的值来为要设置的属性赋值
        mLeftTextColor = ta.getColor(R.styleable.TopBar_leftTextColor, 0);
        mLeftBackground = ta.getDrawable(R.styleable.TopBar_leftBackground);
        mLeftText = ta.getString(R.styleable.TopBar_leftText);
        mRightTextColor = ta.getColor(R.styleable.TopBar_rightTextColor, 0);
        mRightBackground = ta.getDrawable(R.styleable.TopBar_rightBackground);
        mRightText = ta.getString(R.styleable.TopBar_rightText);
        mTitleTextSize = ta.getDimension(R.styleable.TopBar_titleTextSize, 10);
        mTitleTextColor = ta.getColor(R.styleable.TopBar_titleTextColor, 0);
        mTitle = ta.getString(R.styleable.TopBar_title);
        // 1.3 获取完TypedArray的值后，一般要调用recyle方法来避免重新创建的时候的错误
        ta.recycle();

        // 2.1 获取组件元素
        mLeftButton = new Button(context);
        mRightButton = new Button(context);
        mTitleView = new TextView(context);
        // 2.2 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);
        mRightParams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT);
        mRightParams.addRule(RelativeLayout.ALIGN_PARENT_RIGHT, TRUE);
        mTitlepParams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT);
        mTitlepParams.addRule(RelativeLayout.CENTER_IN_PARENT, TRUE);

        // 3.1 为创建的组件元素赋值，就来源于我们在引用的attr.xml文件中给对应属性的赋值
        mLeftButton.setTextColor(mLeftTextColor);
        mLeftButton.setBackground(mLeftBackground);
        mLeftButton.setText(mLeftText);
        mRightButton.setTextColor(mRightTextColor);
        mRightButton.setBackground(mRightBackground);
        mRightButton.setText(mRightText);
        mTitleView.setText(mTitle);
        mTitleView.setTextColor(mTitleTextColor);
        mTitleView.setTextSize(mTitleTextSize);
        mTitleView.setGravity(Gravity.CENTER);

        // 4.1 将组件元素添加到ViewGroup
        addView(mLeftButton, mLeftParams);
        addView(mRightButton, mRightParams);
        addView(mTitleView, mTitlepParams);
        // 4.2 设置按钮的点击事件，不需要具体的实现，只需调用接口的方法，回调的时候，会有具体的实现
        mRightButton.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                mListener.rightClick();
            }
        });
        mLeftButton.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                mListener.leftClick();
            }
        });
    }


    /** * 设置监听 */
    // 接口对象，实现回调机制，在回调方法中通过映射的接口对象调用接口中的方法
    // 而不用去考虑如何实现，具体的实现由调用者去创建
    public interface topbarClickListener {
        // 左按钮点击事件
        void leftClick();
        // 右按钮点击事件
        void rightClick();
    }

    // 映射传入的接口对象
    private topbarClickListener mListener;

    // 暴露一个方法给调用者来注册接口回调，通过接口来获得回调者对接口方法的实现
    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 id * @param flag 是否显示 */
    public void setButtonVisable(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);
            }
        }
    }
}

2.4 topbar_test.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:custom="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:padding="5dp" tools:context=".MainActivity">

    <!-- <include layout="@layout/topbar" /> -->

    <com.imooc.systemwidget.TopBar  android:id="@+id/topBar" android:layout_width="match_parent" android:layout_height="40dp" custom:leftBackground="@drawable/blue_button" custom:leftText="Back" custom:leftTextColor="#FFFFFF" custom:rightBackground="@drawable/blue_button" custom:rightText="More" custom:rightTextColor="#FFFFFF" custom:title="自定义标题" custom:titleTextColor="#123412" custom:titleTextSize="10sp"/>

</RelativeLayout>

2.5 TopBarTest.java

package com.imooc.systemwidget;

public class TopBarTest extends Activity {

    private TopBar mTopbar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.topbar_test);
        // 获得我们创建的topbar
        mTopbar = (TopBar) findViewById(R.id.topBar);
        // 为topbar注册监听事件，传入定义的接口
        // 并以匿名类的方式实现接口内的方法
        mTopbar.setOnTopbarClickListener(
                new TopBar.topbarClickListener() {

                    @Override
                    public void rightClick() {
                        Toast.makeText(TopBarTest.this,
                                "right", Toast.LENGTH_SHORT)
                                .show();
                    }

                    @Override
                    public void leftClick() {
                        Toast.makeText(TopBarTest.this,
                                "left", Toast.LENGTH_SHORT)
                                .show();
                    }
                });
        // 控制topbar上组件的状态
        mTopbar.setButtonVisable(0, true);
        mTopbar.setButtonVisable(1, false);
    }
}