android 自定义 child,Android实现自定义的弹幕效果

一、效果图

先来看看效果图吧~~

二、实现原理方案

1、自定义ViewGroup-XCDanmuView，继承RelativeLayout来实现，当然也可以继承其他三大布局类哈

2、初始化若干个TextView(弹幕的item View，这里以TextView为例，当然也可以其他了~)，然后通过addView添加到自定义View中

3、通过addView添加到XCDanmuView中，位置在坐标，为了实现 从屏幕外移动进来的效果

我们还需要修改添加进来TextView的位置，以从右向左移动方向来说，addView后必须将该TextView的位置设置到右边的屏幕外

这样我们采用的方法，是在onLayout()方法中对childView进行layout重新布局设置位置

4、随机冲左侧或右侧出来弹幕itemView，移动采用属性动画来实现平移，从屏幕的一端移动到另一端，当动画结束后，就将

该child从XCDanmuView中remove掉。并重新new一个弹幕itemView，并addView到XCDanmuView中，并开始动画移动

5、本自定义弹幕View支持从左到右和从右到左两个方向，支持自定义设置屏幕弹幕最多显示个数。

三、自定义弹幕效果XCDanmuView的具体实现

1、初始化需要用到的数据变量

private int mWidth;

private int mScreenWidth;

private List mChildList;

private boolean mIsWorking = false;

private Context mContext;

private int mMaxShowNum = 15;

private int mRowNum = 4;

private int[] mSpeeds = {

3000,4000,5000,6000

};

private int mDelayDuration = 500;

private int[] mBgResIds = {

R.drawable.bg_danmu0,R.drawable.bg_danmu1,R.drawable.bg_danmu2,R.drawable.bg_danmu3

};

private int[] mRowPos = {

150,140,160,150

};

private Random mRandom;

private String[] mStrContents;

public static enum XCDirection{

FROM_RIGHT_TO_LEFT,FORM_LEFT_TO_RIGHT

}

public enum XCAction{

SHOW,HIDE

}

private XCDirection mDirection = XCDirection.FROM_RIGHT_TO_LEFT;

private void init() {

mScreenWidth = getScreenWidth();

mChildList = new ArrayList<>();

mRandom = new Random();

}

2、初始化若干个弹幕item view

public void initDanmuItemViews(String[] strContents){

mStrContents = strContents;

for(int i = 0; i < mMaxShowNum; i ++){

int index = mRandom.nextInt(100) % strContents.length;

createDanmuView(i,strContents[index],false);

}

}

3、创建弹幕item view 并addView到XCDanmuView中

public void createDanmuView(int index,String content,boolean reset){

final TextView textView = new TextView(mContext);

textView.setTextColor(Color.WHITE);

int r = mRandom.nextInt(100) % mRowNum;

textView.setBackgroundResource(mBgResIds[r]);

textView.setText(content +"_"+ (index+1));

RelativeLayout.LayoutParams lp = new LayoutParams(LayoutParams.WRAP_CONTENT,RelativeLayout.LayoutParams.WRAP_CONTENT);

int row = mRandom.nextInt(100) % mRowNum;

while(row == lastRow){

row = mRandom.nextInt(100)% mRowNum;

}

int pos = mRandom.nextInt(100)% mRowNum;

lp.topMargin = row * mRowPos[pos];

lastRow = row;

textView.setLayoutParams(lp);

textView.setPadding(40,2,40,2);

this.addView(textView);

if(reset){

mChildList.set(index,textView);

}else{

mChildList.add(index,textView);

}

textView.setClickable(true);

textView.setOnClickListener(new OnClickListener() {

@Override

public void onClick(View view) {

Toast toast = Toast.makeText(mContext,textView.getText(),Toast.LENGTH_SHORT);

toast.setGravity(Gravity.TOP,50);

toast.show();

}

});

}

4、重新设置childView的初始位置到屏幕之外

@Override

protected void onLayout(boolean changed,int l,int t,int r,int b) {

super.onLayout(changed,l,t,r,b);

int childCount = this.getChildCount();

for(int i=0;i

View view = getChildAt(i);

RelativeLayout.LayoutParams lp = (LayoutParams) view.getLayoutParams();

if(lp.leftMargin <= 0){

if(mDirection == XCDirection.FORM_LEFT_TO_RIGHT){

view.layout(-view.getMeasuredWidth(),lp.topMargin,lp.topMargin + view.getMeasuredHeight());

}else{

view.layout(mScreenWidth,mScreenWidth+view.getMeasuredWidth(),lp.topMargin+view.getMeasuredHeight());

}

}else{

continue;

}

}

}

5、弹幕item view的移动效果

private Handler mHandler = new Handler() {

@Override

public void handleMessage(final Message msg) {

super.handleMessage(msg);

final int pos = msg.what;

ViewPropertyAnimator animator;

if(mDirection == XCDirection.FROM_RIGHT_TO_LEFT){

animator = mChildList.get(msg.what).animate()

.translationXBy(-(mScreenWidth + mChildList.get(msg.what).getWidth()));

}else{

animator = mChildList.get(msg.what).animate()

.translationXBy(mScreenWidth + mChildList.get(msg.what).getWidth());

}

Random random = new Random(System.currentTimeMillis());

int index = random.nextInt(100) % mSpeeds.length;

animator.setDuration(mSpeeds[index]);

animator.setInterpolator(new LinearInterpolator());

animator.setListener(new Animator.AnimatorListener() {

@Override

public void onAnimationStart(Animator animator) {

}

@Override

public void onAnimationEnd(Animator animator) {

XCDanmuView.this.removeView(mChildList.get(pos));

int index = mRandom.nextInt(100) % mStrContents.length;

createDanmuView(pos,mStrContents[index],true);

mHandler.sendEmptyMessageDelayed(pos,mDelayDuration);

Log.v("czm","size=" + mChildList.size());

}

@Override

public void onAnimationCancel(Animator animator) {

}

@Override

public void onAnimationRepeat(Animator animator) {

}

});

animator.start();

}

};

6、开启弹幕效果和关闭弹幕效果以及对于的动画效果

boolean isFirst = true;

public void start(){

switchAnimation(XCAction.SHOW);

if(isFirst){

for(int i =0;i< mChildList.size();i++){

mHandler.sendEmptyMessageDelayed(i,i * mDelayDuration);

}

isFirst = false;

}

mIsWorking = true;

}

public void hide(){

switchAnimation(XCAction.HIDE);

mIsWorking =false;

}

public void stop(){

this.setVisibility(View.GONE);

for(int i =0;i< mChildList.size();i++){

mChildList.get(i).clearAnimation();

mHandler.removeMessages(i);

}

mIsWorking =false;

}

private void switchAnimation(final XCAction action){

AlphaAnimation animation;

if(action == XCAction.HIDE){

animation = new AlphaAnimation(1.0f,0.0f);

animation.setDuration(400);

}else{

animation = new AlphaAnimation(0.0f,1.0f);

animation.setDuration(1000);

}

XCDanmuView.this.startAnimation(animation);

animation.setAnimationListener(new Animation.AnimationListener() {

@Override

public void onAnimationStart(Animation animation) {

}

@Override

public void onAnimationEnd(Animation animation) {

if(action == XCAction.HIDE){

XCDanmuView.this.setVisibility(View.GONE);

}else{

XCDanmuView.this.setVisibility(View.VISIBLE);

}

}

@Override

public void onAnimationRepeat(Animation animation) {

}

});

}

四、如何使用该自定义侧滑View控件

使用该自定义View非常简单，控件默认效果从右向左，如果需要修改方向为从左到右，只需设置下方向即可

public class MainActivity extends Activity {

private XCDanmuView mDanmuView;

private List mViewList;

private String[] mStrItems = {

"搜狗","百度","腾讯","360","阿里巴巴","搜狐","网易","新浪","搜狗-上网从搜狗开始","百度一下,你就知道","必应搜索-有求必应","好搜-用好搜，特顺手","Android-谷歌","IOS-苹果","Windows-微软","Linux"

};

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

initDanmuView();

initListener();

}

private void initListener() {

findViewById(R.id.btn).setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View view) {

if (mDanmuView.isWorking()) {

mDanmuView.hide();

((Button) view).setText("开启弹幕");

} else {

mDanmuView.start();

((Button) view).setText("关闭弹幕");

}

}

});

}

private void initDanmuView() {

mDanmuView = (XCDanmuView)findViewById(R.id.danmu);

mDanmuView.initDanmuItemViews(mStrItems);

}

}

五、总结

以上就是在Android中实现自定义弹幕效果的全部内容个，希望本文的内容对大家开发Android的时候能有所帮助。如果有疑问可以留言交流。

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