为自定View添加相应属性，在XML可以直接使用

declare-styleable

<?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="titleTextColor" format="color"></attr>
<attr name="leftTextColor" format="color"></attr>
<attr name="leftBackground" format="color|reference"></attr>
<attr name="leftText" format="string"></attr>
<attr name="rightText" format="string"></attr>
<attr name="rightBackground" format="color|reference"></attr>
<attr name="rightTextColor" format="color"></attr>
</declare-styleable>
</resources>

XML布局

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:custom="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
>

<com.example.hc.mytopbar.TopBar
android:id="@+id/tp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
custom:leftText="back"
custom:leftTextColor="#ffff00"
custom:rightTextColor="#ffff00"
custom:rightText="menu"
custom[b]:title="菜单"
custom:titleTextColor="#123412"
custom:titleTextSize="10sp">

</com.example.hc.mytopbar.TopBar>

</RelativeLayout>

然后在自定义View类中的构造函数中 通过

TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.Topbar); 获得这个atts文件

获得atts中自定义属性之后 将属性与相应的控件绑定

public class TopBar extends RelativeLayout {
private Button leftButton, rightButton;
private TextView tv_title;

private int leftTextColor;
private Drawable leftBackground;
private String leftText;
private int rightTextColor;
private Drawable rightBackground;
private String rightText;

private float titleTextSize;
private int titleTextColor;
private String title;

private LayoutParams leftParams, rightParams, titleParam;

private topbarClickListener listener;

public interface topbarClickListener {
public void leftClick();

public void rightClick();
}

public void setOnTopbarClickListener(topbarClickListener listner) {
this.listener = listner;
}

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

TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.Topbar);
leftTextColor = ta.getColor(R.styleable.Topbar_leftTextColor, 0);
leftBackground = ta.getDrawable(R.styleable.Topbar_leftBackground);
leftText = ta.getString(R.styleable.Topbar_leftText);

rightTextColor = ta.getColor(R.styleable.Topbar_rightTextColor, 0);
rightBackground = ta.getDrawable(R.styleable.Topbar_rightBackground);
rightText = ta.getString(R.styleable.Topbar_rightText);

titleTextSize = ta.getDimension(R.styleable.Topbar_titleTextSize, 0);
titleTextColor = ta.getColor(R.styleable.Topbar_titleTextColor, 0);
title = ta.getString(R.styleable.Topbar_title);

ta.recycle();
setBackgroundColor(0xfff59563);
leftButton = new Button(context);
rightButton = new Button(context);
tv_title = new TextView(context);

leftButton.setTextColor(leftTextColor);
leftButton.setText(leftText);
leftButton.setBackground(leftBackground);
rightButton.setText(rightText);
rightButton.setTextColor(rightTextColor);
rightButton.setBackground(rightBackground);
tv_title.setTextColor(titleTextColor);
tv_title.setTextSize(titleTextSize);
tv_title.setText(title);
tv_title.setGravity(Gravity.CENTER);

leftParams = new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
leftParams.addRule(ALIGN_PARENT_LEFT, TRUE);

addView(leftButton, leftParams);

rightParams = new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
rightParams.addRule(ALIGN_PARENT_RIGHT, TRUE);

addView(rightButton, rightParams);

titleParam = new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
titleParam.addRule(CENTER_IN_PARENT);
addView(tv_title, titleParam);