Android 自定义View：TopBar

概述

源码下载

效果图

代码展示：

MainActivity.java :

import com.zhuanghongji.customviewzhj.view.TopBar;

public class MainActivity extends AppCompatActivity {

TopBar mTopBar;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

mTopBar = (TopBar) findViewById(R.id.topBar);

//        mTopBar.setLeftButtonIsVisible(false);

mTopBar.setOnTopBarClickListener(new TopBar.TopBarClickListener() {
@Override
public void leftBtnClick() {
Toast.makeText(MainActivity.this, " 点击了 leftBtn ", Toast.LENGTH_SHORT).show();
}
});
}

}

activity_main.xml :

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:zhj="http://schemas.android.com/apk/res-auto"
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"
tools:context=".MainActivity">

<com.zhuanghongji.customviewzhj.view.TopBar
android:id="@+id/topBar"
android:layout_width="match_parent"
android:layout_height="56dp"
zhj:leftBtnBackground="#ff0000"
zhj:leftBtnText="leftBtn"
zhj:leftBtnTextColor="#000000"
zhj:titleText="我是自定义的title"
zhj:titleTextColor="#000000"
zhj:titleTextSize="18sp"
zhj:topBarBackground="#00ff00">

</com.zhuanghongji.customviewzhj.view.TopBar>

</RelativeLayout>

TopBar.java :

import com.zhuanghongji.customviewzhj.R;

public class TopBar extends RelativeLayout {

private Button mLeftBtn;
private TextView mTitleTv;

// 左Button属性
private int leftBtnTextColor;
private Drawable leftBtnBackground;
private String leftBtnText;

// title属性
private int titleTextColor;
private String titleText;
private float titleTextSize;

// topBar属性
private Drawable topBarBackground;

// 布局属性
private LayoutParams leftBtnParams, titleParams;

// 点击事件监听器接口 -- public
public interface TopBarClickListener {
public void leftBtnClick();
}

private TopBarClickListener listener;

// 设置监听器
public void setOnTopBarClickListener(TopBarClickListener listener) {
this.listener = listener;
}

// 供调用的方法
public void setLeftButtonIsVisible(boolean visible) {
if (visible) {
mLeftBtn.setVisibility(View.VISIBLE);
} else {
mLeftBtn.setVisibility(View.GONE);
}
}

// 三个构造方法，均调用均调用三个参数的那个
public TopBar(Context context) {
this(context, null);
}

public TopBar(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}

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

TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.TopBar);
// 取自定义属性 -- leftBtn
leftBtnText = ta.getString(R.styleable.TopBar_leftBtnText);
leftBtnTextColor = ta.getColor(R.styleable.TopBar_leftBtnTextColor, Color.WHITE);
leftBtnBackground = ta.getDrawable(R.styleable.TopBar_leftBtnBackground);
// 取自定义属性 -- title
titleText = ta.getString(R.styleable.TopBar_titleText);
titleTextColor = ta.getColor(R.styleable.TopBar_titleTextColor, Color.WHITE);
titleTextSize = ta.getDimension(R.styleable.TopBar_titleTextSize, 12);
// 取自定义属性 -- topBar
topBarBackground = ta.getDrawable(R.styleable.TopBar_topBarBackground);
//回收TypeArray(避免浪费资源，避免以为缓存导致的错误)
ta.recycle();

mLeftBtn = new Button(context);
mTitleTv = new TextView(context);

//设置自定义属性
mLeftBtn.setText(leftBtnText);
mLeftBtn.setTextColor(leftBtnTextColor);
mLeftBtn.setBackground(leftBtnBackground);

mTitleTv.setText(titleText);
mTitleTv.setTextSize(titleTextSize);
mTitleTv.setTextColor(titleTextColor);

setBackground(topBarBackground);  // 可以通过此代码改变topBar背景色
//        setBackgroundColor(0x00ff00); // 在这里我们直接设置成绿色

// 设置布局 -- 左Button
leftBtnParams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
leftBtnParams.addRule(RelativeLayout.ALIGN_PARENT_LEFT, TRUE);
leftBtnParams.addRule(RelativeLayout.CENTER_VERTICAL, TRUE);
addView(mLeftBtn, leftBtnParams);

// 设置布局 -- title
titleParams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
titleParams.addRule(RelativeLayout.CENTER_IN_PARENT, TRUE);
addView(mTitleTv, titleParams);

mLeftBtn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
listener.leftBtnClick();    //左Button点击事件
}
});
}

}

attrs.xml :

<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="TopBar">
<!--文字-->
<attr name="leftBtnText" format="string"/>
<attr name="titleText" format="string"/>
<!--文字颜色-->
<attr name="leftBtnTextColor" format="color"/>
<attr name="titleTextColor" format="color"/>
<!--文字大小-->
<attr name="titleTextSize" format="dimension"/>
<!--背景色,因为有时候也会用到数值来表达颜色，所以加上reference格式-->
<attr name="leftBtnBackground" format="reference|color" />
<attr name="topBarBackground" format="reference|color" />

</declare-styleable>
</resources>