Android开发之自定义View(视图)用法详解

package com.viewTest;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.Paint.Style;
import android.util.AttributeSet;
import android.view.View;
public class MyView extends View {
  public MyView(Context context) {
    super(context);
    // TODO Auto-generated constructor stub
  }
  public MyView(Context context,AttributeSet attr) {
    super(context,attr);
  }
  private Paint myPaint;
  private static final String myString1 = "2006-2011上半年中国移动互联网行业各年度投资情况";
  private static final String myString2 = "来源：清科研究中心 2011.08";
  @Override
  protected void onDraw(Canvas canvas) {
    // TODO Auto-generated method stub
    super.onDraw(canvas);
    myPaint = new Paint();
    //绘制标题
    myPaint.setColor(Color.BLACK); //设置画笔颜色
    myPaint.setTextSize(18);//设置文字大小
    canvas.drawText(myString1, 20, 20, myPaint);
    //绘制坐标轴
    canvas.drawLine(50, 100, 50, 500, myPaint);//纵坐标轴
    canvas.drawLine(50, 500, 400, 500, myPaint);//横坐标轴
    int[] array1 = new int[]{0, 50, 100, 150, 200, 250, 300, 350};
    //绘制纵坐标刻度
    myPaint.setTextSize(10);//设置文字大小
    canvas.drawText("单位：百万美元", 20, 90, myPaint);
    for (int i = 0; i < array1.length; i++) {
      canvas.drawLine(50, 500 - array1[i], 54, 500 - array1[i], myPaint);
      canvas.drawText(array1[i] + "", 20, 500 - array1[i], myPaint);
    }
    //绘制横坐标文字
    String[] array2 = new String[]{"2008年", "2009年", "2010年", "2011上半年"};
    for (int i = 0; i < array2.length; i++) {
      canvas.drawText(array2[i], array1[i] + 80, 520, myPaint);
    }
    //绘制条形图
    myPaint.setColor(Color.BLUE); //设置画笔颜色
    myPaint.setStyle(Style.FILL); //设置填充
    canvas.drawRect(new Rect(90, 500 - 56, 110, 500), myPaint);//画一个矩形,前两个参数是矩形左上角坐标，后两个参数是右下角坐标
    canvas.drawRect(new Rect(140, 500 - 98, 160, 500), myPaint);//第二个矩形
    canvas.drawRect(new Rect(190, 500 - 207, 210, 500), myPaint);//第三个矩形
    canvas.drawRect(new Rect(240, 500 - 318, 260, 500), myPaint);//第四个矩形
    myPaint.setColor(Color.BLACK); //设置画笔颜色
    canvas.drawText("56.32", 88, 500 - 58, myPaint);//第一个矩形的数字说明
    canvas.drawText("98.00", 138, 500 - 100, myPaint);
    canvas.drawText("207.65", 188, 500 - 209, myPaint);
    canvas.drawText("318.30", 238, 500 - 320, myPaint);
    //绘制出处
    myPaint.setColor(Color.BLACK); //设置画笔颜色
    myPaint.setTextSize(16);//设置文字大小
    canvas.drawText(myString2, 20, 560, myPaint);
  }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  android:orientation="vertical" >
  <TextView
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="@string/hello" />
  <Button
    android:layout_width="match_parent"
    android:layout_height="40dip"
    android:text="下一张图" />
  <com.viewTest.MyView
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:background="#FFFFFF"/>
</LinearLayout>