自定义控件

详细可以参考《第一行代码》p121

所有的view都是这样继承的，所以我们也可以自己继承，就是自定义控件。

activity_title.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@drawable/title_bg" >

    <Button
        android:id="@+id/title_back"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="5dp"
        android:background="@drawable/back_bg"
        android:text="Back"
        android:textColor="#fff" />

    <TextView
        android:id="@+id/title_text"
        android:layout_width="0dip"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:gravity="center"
        android:text="This is Title"
        android:textColor="#fff"
        android:textSize="22sp" />

    <Button
        android:id="@+id/title_edit"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="5dp"
        android:background="@drawable/edit_bg"
        android:text="Edit"
        android:textColor="#fff" />

</LinearLayout>

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >
    <com.example.define.TitleLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        ></com.example.define.TitleLayout>

</RelativeLayout>

TitleLayout.java

package com.example.define;

import android.app.Activity;
import android.content.Context;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.Toast;

public class TitleLayout extends LinearLayout {
    public TitleLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
        LayoutInflater.from(context).inflate(R.layout.activity_title, this);
        Button back=(Button) findViewById(R.id.title_back);
        Button edit=(Button) findViewById(R.id.title_edit);
        back.setOnClickListener(new OnClickListener() {
            
            @Override
            public void onClick(View v) {
                ((Activity) getContext()).finish();
            }
        });
        edit.setOnClickListener(new OnClickListener() {
            
            @Override
            public void onClick(View v) {
                Toast.makeText(getContext(), "你点击了编辑", 0).show();
            }
        });
    }
}

MainActivity.java

package com.example.define;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;

public class MainActivity extends Activity {

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