自定义控件

1.自定义标题栏

android:background="@drawable/title_bg"  指定背景

android:layout_margin="5dp"  指定控件在上下左右方向上偏移

android:layout_marginTop="5dp"   指定控件向下偏移5dp

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:background="@drawable/title_bg">

    <Button
        android:id="@+id/title_back"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_margin="5dp"
        android:text="back"
        android:textColor="#fff"/>

    <TextView
        android:id="@+id/title_text"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_weight="1"
        android:text="Title Text"
        android:gravity="center"/>
    <Button
        android:id="@+id/title_edit"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_margin="5dp"
        android:text="edit"
        android:textColor="#fff"/>
</LinearLayout>

2.引入布局

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <include layout="@layout/title"
</LinearLayout>

3.隐藏系统自带的标题栏

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ActionBar actionbar = getSupportActionBar();
        if (actionbar != null){
            actionbar.hide();
        }
    }
}

4.创建自定义控件

借助LayoutInflater实现对标题栏布局的动态加载

public class TitleLayout extends LinearLayout{
    public TitleLayout(Context context, AttributeSet attrs){
        super(context,attrs);
        LayoutInflater.from(context).inflate(R.layout.title,this);
    }
}

5.在布局文件中添加自定义控件

添加自定义控件时，需要指明控件的完整类名，包名不能省略

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <com.example.lu.uicustomviews.TitleLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
</LinearLayout>

6.给按钮注册点击事件

public class TitleLayout extends LinearLayout{
    public TitleLayout(Context context, AttributeSet attrs){
        super(context,attrs);
        LayoutInflater.from(context).inflate(R.layout.title,this);
        Button titleBack = (Button) findViewById(R.id.title_back);
        Button titleEdit = (Button) findViewById(R.id.title_edit);
        titleBack.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                ((Activity) getContext()).finish();
            }
        });
        titleEdit.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(getContext(),"You clicked Edit button",Toast.LENGTH_SHORT).show();
            }
        });
    }
}