Android应用开发揭秘之5.2.1 Paint类介绍

 

 

 

package com.yarin.android.Examples_05_03;

 

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 */

        // 肯定是一个空心的矩形

        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();

        }

    }

}