Android应用开发揭秘的第8个程序5_3_PaintDraw修改版和高仿版的源码注释

//学会运用PaintDraw画笔

Activity01.java

 

package com.PaintDraw;

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

public class Activity01 extends Activity
{
 
 private GameView mGameView;
 /** Called when the activity is first created. */
 @Override
 public void onCreate(Bundle savedInstanceState)
 {
  super.onCreate(savedInstanceState);
  
  mGameView = new GameView(this);
  
  setContentView(mGameView);
 }
}

 

GameView.java

 

package com.PaintDraw;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.Log;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.View;

public class GameView extends View implements Runnable
{

 public final static String TAG  = "Examples_05_03_GameView"; //
 /* 声明Paint对象 */
 private Paint    mPaint = null;

 public GameView(Context context)
 {
  super(context);
  /* 构建对象 */
  mPaint = new Paint();

  /* 开启线程 */
  new Thread(this).start();
 }

 public void onDraw(Canvas canvas)
 {
  super.onDraw(canvas);

  /* 设置Paint为无锯齿 */
  mPaint.setAntiAlias(true);

  /* 设置Paint的颜色 */
  mPaint.setColor(Color.RED);
  mPaint.setColor(Color.BLUE);
  mPaint.setColor(Color.YELLOW);
  mPaint.setColor(Color.GREEN);
  /* 同样是设置颜色 */
  mPaint.setColor(Color.rgb(255, 0, 0));

  /* 提取颜色 */
  Color.red(0xcccccc);
  Color.green(0xcccccc);

  /* 设置paint的颜色和Alpha值(a,r,g,b) */
  mPaint.setARGB(255, 255, 0, 0);

  /* 设置paint的Alpha值 */
  mPaint.setAlpha(220);

  /* 这里可以设置为另外一个paint对象 */
  // mPaint.set(new Paint());
  /* 设置字体的尺寸 */
  mPaint.setTextSize(14);

  // 设置paint的风格为“空心”.
  // 当然也可以设置为“实心”(Paint.Style.FILL)
  mPaint.setStyle(Paint.Style.STROKE);

  // 设置“空心”的外框的宽度。
  mPaint.setStrokeWidth(5);

  /* 得到Paint的一些属性 */
  Log.i(TAG, "paint的颜色：" + mPaint.getColor());

  Log.i(TAG, "paint的Alpha：" + mPaint.getAlpha());

  Log.i(TAG, "paint的外框的宽度：" + mPaint.getStrokeWidth());

  Log.i(TAG, "paint的字体尺寸：" + mPaint.getTextSize());

  /* 绘制一个矩形 */
  // 肯定是一个空心的举行
  canvas.drawRect((320 - 80) / 2, 20, (320 - 80) / 2 + 80, 20 + 40, mPaint);

  /* 设置风格为实心 */
  mPaint.setStyle(Paint.Style.FILL);

  mPaint.setColor(Color.GREEN);

  /* 绘制绿色实心矩形 */
  canvas.drawRect(0, 20, 40, 20 + 40, mPaint);
 }

 // 触笔事件
 public boolean onTouchEvent(MotionEvent event)
 {
  return true;
 }

 // 按键按下事件
 public boolean onKeyDown(int keyCode, KeyEvent event)
 {
  return true;
 }

 // 按键弹起事件
 public boolean onKeyUp(int keyCode, KeyEvent event)
 {
  return false;
 }

 public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event)
 {
  return true;
 }

 public void run()
 {
  while (!Thread.currentThread().isInterrupted())
  {
   try
   {
    Thread.sleep(100);
   }
   catch (InterruptedException e)
   {
    Thread.currentThread().interrupt();
   }
   // 使用postInvalidate可以直接在线程中更新界面
   postInvalidate();
  }
 }
}

 

 

 

Gf_PaintDrawActivity.java

 

package packagename.GfPaintDraw;

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

public class Gf_PaintDrawActivity extends Activity
{
 private GameView mGameView;
 /** Called when the activity is first created. */
 @Override
 public void onCreate(Bundle savedInstanceState)
 {
  super.onCreate(savedInstanceState);
  
  mGameView = new GameView(this);
  
  setContentView(mGameView);
 }
}