从零開始学android<Bitmap图形组件.四十七.>

<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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <com.example.bitmap1.MyView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">
	</com.example.bitmap1.MyView>

</RelativeLayout>

package com.example.bitmap1;

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

public class MainActivity extends Activity {

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

package com.example.bitmap1;
              
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
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 {

	public MyView(Context context, AttributeSet attrs) {
		super(context, attrs);
		// TODO Auto-generated constructor stub
	}

	@Override
	protected void onDraw(Canvas canvas) {
		// TODO Auto-generated method stub
//		获取图片文件
		Bitmap bitmap = BitmapFactory.decodeResource(super.getResources(),
				R.drawable.a4);
//		设置背景画布颜色
		canvas.drawColor(Color.WHITE);
//		初始化画笔
		Paint paint=new Paint();
//		设置边缘羽化
		paint.setAntiAlias(true);
//		绘制图片
		canvas.drawBitmap(bitmap, 0, 0,paint );
//		设置画笔颜色
		paint.setColor(Color.BLUE);
//		设置字体尺寸
		paint.setTextSize(20);
//		绘制文字
		canvas.drawText("我的头像", 10, bitmap.getHeight()+20, paint);
	}
}