自定义组件

<resources>
    <declare-styleable name="myView">
        <attr name="textSize" format="dimension"/>
        <attr name="textColor" format="color"/>
        <attr name="text" format="string"/>
    </declare-styleable>
</resources>

自定义组件在这里使用：

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:myandroid="http://schemas.android.com/apk/res/com.ybj.lesson"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center">
        <Button 
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="列表"
            android:id="@+id/bt_list"/>
        <com.ybj.lesson.MyView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            myandroid:textSize="30sp"
            myandroid:textColor="#00ff00">
        </com.ybj.lesson.MyView>
</LinearLayout>

自定义组件控制类：

package com.ybj.lesson;

import com.ybj.lesson.R;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;

public class MyView extends View {

    private Paint paint = null;;

    public MyView(Context context, AttributeSet attrs) {
        super(context, attrs);
        // TODO Auto-generated constructor stub
        //取出属性文件
        TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.myView);
        //取出属性
        float textSize = array.getDimension(R.styleable.myView_textSize, 25);
        int textColor = array.getColor(R.styleable.myView_textColor, Color.BLUE);
        String text = array.getString(R.styleable.myView_text);

        paint = new Paint();
        paint.setColor(textColor);
        paint.setTextSize(textSize);
        //关闭资源
        array.recycle();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        // TODO Auto-generated method stub
        super.onDraw(canvas);
        //绘制组件内容
        canvas.drawText("aaaa", 10, 30, paint);
        canvas.drawCircle(10, 20, 6, paint);
    }
}