android 自定义view的简单实例

1，提取和封装 使用抽象方法

package com.example.androidmyview.v3;

import android.content.Context;

import android.graphics.Canvas;

import android.util.AttributeSet;

import android.view.View;

public abstract class BaseView extends View {

 

 private mythread thread;

 public BaseView(Context context) {

  super(context);

 }

 public BaseView(Context context, AttributeSet attrs) {

  super(context, attrs);

 }

 public BaseView(Context context, AttributeSet attrs, int defStyleAttr) {

  super(context, attrs, defStyleAttr);

 }

 @Override

 protected void onDraw(Canvas canvas) {

  if (thread == null) {

   thread = new mythread();

   thread.start();

  }else {

   drawsub(canvas);

  }

 }

 

 /**

  * 绘制方法

  * @param canvas

  */

 protected  abstract void drawsub(Canvas canvas);

 

 /**

  * 逻辑运算

  */

 protected abstract void Logic();

 /**

  * 自定义线程

  * @author Administrator

  *

  */

 class mythread extends Thread {

  @Override

  public void run() {

   while (true) {

    Logic();

    //从新绘制

    postInvalidate();

    try {

     Thread.sleep(30);

    } catch (InterruptedException e) {

     e.printStackTrace();

    }

   }

  }

 };

}

-----------------------------------------------

package com.example.androidmyview.v3;

import java.util.Random;

import android.content.Context;

import android.graphics.Canvas;

import android.graphics.Paint;

import android.graphics.RectF;

import android.util.AttributeSet;

public class LogicView extends BaseView{

 private Paint paint;

 private float x = 0;

 private static String text ="LogicView";

 private RectF rectf;

 private float sweepAngle =0;

 private Random random;

 

 public LogicView(Context context) {

  super(context);

 }

 public LogicView(Context context, AttributeSet attrs) {

  super(context, attrs);

 }

 public LogicView(Context context, AttributeSet attrs, int defStyleAttr) {

  super(context, attrs, defStyleAttr);

 }

 @Override

 protected void drawsub(Canvas canvas) {

  paint = new Paint();

  paint.setTextSize(30);

  rectf = new RectF(0,60,100,160);

  canvas.drawText(text, x, 30, paint);

  canvas.drawArc(rectf, 0, sweepAngle, true, paint);

 }

 @Override

 protected void Logic() {

  random  = new Random();

  x += 3;

  if (x>getWidth()) {

   x=0-paint.measureText(text);

  }

  sweepAngle++;

  if (sweepAngle>360) {

   sweepAngle=0;

  }

  //产生随机数

  int r = random.nextInt(256);

  int g = random.nextInt(256);

  int b = random.nextInt(256);

  //颜色不断变化

  paint.setARGB(255, r, g, b);

 }

}

---------------------------------------------

布局文件采用framelayout

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:id="@+id/container"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    >

    <com.example.androidmyview.v1.Myview 

        android:layout_width="match_parent"

        android:layout_height="match_parent"

        android:visibility="gone"/>

   <com.example.androidmyview.v3.LogicView

      android:layout_width="match_parent"

      android:layout_height="match_parent"

      />

</FrameLayout>

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使用xml文件解析自定义view