自定义View实例——下雨天画面(通过布局文件.xml中的自定义属性来设值)

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.cctvjiatao.rainview"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
android:minSdkVersion="14"
android:targetSdkVersion="21" />

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".MainActivity2"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>

</manifest>

com.cctvjiatao.rainview.MainActivity2

package com.cctvjiatao.rainview;

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

public class MainActivity2 extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
}
}

activity_main2.xml

<pre name="code" class="html"><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:jiatao = "http://schemas.android.com/apk/res/com.cctvjiatao.rainview"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.cctvjiatao.rainview.MainActivity" >

<com.cctvjiatao.rainview.v3.ManyRain
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#ff000000"
jiatao:rainNum = "100"
jiatao:size = "100"
jiatao:rainColor = "0xffffffff"
jiatao:randColor = "false"
/>

</RelativeLayout>

res/value/attrs.xml(新建的资源文件)

<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="RainView">
<attr name="rainNum" format="integer"/>
<attr name="size" format="integer"/>
<attr name="rainColor" format="integer"/>
<attr name="randColor" format="boolean"/>
</declare-styleable>

</resources>

com.cctvjiatao.rainview.v2.BaseView

<pre name="code" class="java">package com.cctvjiatao.rainview.v2;

import android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.view.View;

/**
* @作者： jiatao
* @修改时间：2016-3-13 下午12:23:39
* @包名：com.cctvjiatao.rainview.v2
* @文件名：BaseView.java
* @版权声明：www.cctvjiatao.com
* @功能： 自定义View的封装类
*/
public abstract class BaseView extends View {

private DrawThread thread;
private boolean isRunning = true;
private long sleepTime = 30;

public BaseView(Context context, AttributeSet attrs) {
super(context, attrs);
}

public BaseView(Context context) {
super(context);
}

protected abstract void drawSub(Canvas canvas);

protected abstract void drawLogic();

protected abstract void init();

@Override
protected final void onDraw(Canvas canvas) {

if (thread == null) {
thread = new DrawThread();
thread.start();
} else {
drawSub(canvas);
}
}

@Override
protected void onDetachedFromWindow() {
super.onDetachedFromWindow();
isRunning = false;
}

class DrawThread extends Thread {

@Override
public void run() {
init();
while (isRunning) {
drawLogic();
postInvalidate();
try {
Thread.sleep(sleepTime);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}

}

com.cctvjiatao.rainview.v2.RainItem

</pre><pre name="code" class="java">package com.cctvjiatao.rainview.v2;

import java.util.Random;

import android.graphics.Canvas;
import android.graphics.Paint;
/**
* @作者： jiatao
* @修改时间：2016-3-13 下午12:33:39
* @包名：com.cctvjiatao.rainview.v2
* @文件名：RainItem.java
* @版权声明：www.cctvjiatao.com
* @功能： 雨滴的封装类
*/
public class RainItem {

private int width, height;
private float startX, startY, stopX, stopY, sizeX, sizeY;
private float speed;// 可控制速度
private Random random;
private Paint paint = new Paint();

private int size = 20;
private int color ;
private boolean randColor = false;;

public RainItem(int width, int height) {
this.width = width;
this.height = height;
init();
}

public RainItem(int width, int height, int size) {
this.size = size;
this.width = width;
this.height = height;
init();
}

public RainItem(int width, int height, int size, int color) {
this.color = color;
this.size = size;
this.width = width;
this.height = height;
init();
}

public RainItem(int width, int height, int size, int color, boolean randColor) {
this.randColor = randColor;
this.color = color;
this.size = size;
this.width = width;
this.height = height;
init();
}

public RainItem(int width, int height, int size, int color, boolean randColor, float speed) {
this.randColor = randColor;
this.color = color;
this.size = size;
this.speed = speed;
this.width = width;
this.height = height;
init();
}

private void init() {
random = new Random();
sizeX = 1 + random.nextInt(size / 2);
sizeY = 10 + random.nextInt(size);
startX = random.nextInt(width);
startY = random.nextInt(height);
stopX = startX + sizeX;
stopY = startY + sizeY;
speed = 0.2f + random.nextFloat();
paint = new Paint();
if (randColor) {
int r = random.nextInt(256);
int g = random.nextInt(256);
int b = random.nextInt(256);

paint.setARGB(255, r, g, b);
} else {
paint.setColor(color);
}
}

public void draw(Canvas canvas) {
canvas.drawLine(startX, startY, stopX, stopY, paint);
}

public void move() {
startX += sizeX * speed;
stopX += sizeX * speed;
startY += sizeY * speed;
stopY += sizeY * speed;
if (startY > height) {
init();
}
}
}

com.cctvjiatao.rainview.v3.ManyRain

<pre name="code" class="java">package com.cctvjiatao.rainview.v3;

import java.util.ArrayList;

import com.cctvjiatao.rainview.R;
import com.cctvjiatao.rainview.v2.BaseView;
import com.cctvjiatao.rainview.v2.RainItem;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.util.AttributeSet;

/**
* @作者： jiatao
* @修改时间：2016-3-13 下午14:33:39
* @包名：com.cctvjiatao.rainview.v2
* @文件名：ManyRain.java
* @版权声明：www.cctvjiatao.com
* @功能： 下雨的执行类,通过布局文件.xml中的自定义属性来设值
*/
public class ManyRain extends BaseView {

private ArrayList<RainItem> list = new ArrayList<RainItem>();
private int rainNum;// 雨滴的数量
private int size;// 移动的距离
private int rainColor;// 画笔的初始颜色
private boolean randColor; // 是否变色

public ManyRain(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.RainView);
rainNum = ta.getInteger(R.styleable.RainView_rainNum, 80);
size = ta.getInteger(R.styleable.RainView_size, 20);
rainColor = ta.getInteger(R.styleable.RainView_rainColor, 0xffffffff);
randColor = ta.getBoolean(R.styleable.RainView_randColor, false);
ta.recycle();
}

public ManyRain(Context context) {
super(context);
}

@Override
protected void drawSub(Canvas canvas) {

for (RainItem item : list) {
item.draw(canvas);
}
}

@Override
protected void drawLogic() {
for (RainItem item : list) {
item.move();
}
}

@Override
protected void init() {
for (int i = 0; i < rainNum; i++) {
RainItem item = new RainItem(getWidth(), getHeight(), size, rainColor, randColor);
list.add(item);
}
}

}