自定义View的导航栏

//自定义View类
package com.example.zdyview.View;

import android.content.Context;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.Button;
import android.widget.RelativeLayout;
import android.widget.TextView;

import com.example.zdyview.R;

public class TitleView extends RelativeLayout {

private  Button btn;
private TextView title_template;

public TitleView(Context context, AttributeSet attrs) {
    super(context, attrs);
    //加载布局
    LayoutInflater.from(context).inflate(R.layout.title_bar,this);
    //获取控件
    btn = findViewById(R.id.left_btn);
    title_template = findViewById(R.id.title_template);
}
//为左侧按钮添加点击事件
public void setLeftButtonListener(OnClickListener listener) {
   btn.setOnClickListener(listener);
}
//设置标题的方法
public void setTitle(String title){
    title_template.setText(title);
}

}