Android仿微信群聊头像效果

public class NineGridImageView<T  extends ViewGroup{
private int mRowCount; //行数
private int mColumnCount; //列数
private int mMaxSize = 9; //最大图片数
private int mGap; //宫格间距
private int parentWidth;//父组件宽
private int parentHeight;//父组件高
private List<ImageView  mImageViewList = new ArrayList< ();
private List<T  mImgDataList;
private NineGridImageViewAdapter<T  mAdapter;
public NineGridImageView(Context context) {
this(context,null);
}
public NineGridImageView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public NineGridImageView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.NineGridImageView);
this.mGap = (int) typedArray.getDimension(R.styleable.NineGridImageView_imgGap, 8);
typedArray.recycle();
}
/**
* 设定宽高
*/
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
parentWidth = measureWidth(widthMeasureSpec);
parentHeight = measureHeight(heightMeasureSpec);
setMeasuredDimension(parentWidth,parentHeight);
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
layoutChildrenView();
}
/**
* 为子ImageView布局
*/
private void layoutChildrenView(){
if(mImgDataList == null){
return;
}
int childrenCount = mImgDataList.size();
for(int i = 0; i < childrenCount; i++){
ImageView childrenView = (ImageView)getChildAt(i);
if(mAdapter != null){
mAdapter.onDisplayImage(getContext(), childrenView, mImgDataList.get(i));
}
int rowNum = i / mColumnCount;//当前行数
int columnNum = i % mColumnCount;//当前列数
int mImageSize = (parentWidth-(mColumnCount+1)*mGap)/mColumnCount;//图片尺寸
int t_center = (parentHeight + mGap)/2;//中间位置以下的顶点（有宫格间距）
int b_center = (parentHeight - mGap)/2;//中间位置以上的底部（有宫格间距）
int l_center = (parentWidth + mGap)/2;//中间位置以右的左部（有宫格间距）
int r_center = (parentWidth - mGap)/2;//中间位置以左的右部（有宫格间距）
int center = (parentHeight - mImageSize)/2;//中间位置以上顶部（无宫格间距）
int left = mImageSize * columnNum + mGap * (columnNum + 1);
int top = mImageSize * rowNum + mGap * (rowNum + 1);
int right = left + mImageSize;
int bottom = top + mImageSize;
/**
* 不同子view情况下的不同显示
*/
if(childrenCount == 1){
childrenView.layout(left, top, right, bottom);
}else if(childrenCount == 2){
childrenView.layout(left, center, right, center + mImageSize);
}else if(childrenCount == 3){
if(i == 0){
childrenView.layout(center, top, center+mImageSize, bottom);
}else {
childrenView.layout(mGap * i +mImageSize * (i - 1), t_center, mGap * i +mImageSize * i, t_center+mImageSize);
}
}else if(childrenCount == 4){
childrenView.layout(left, top, right, bottom);
}else if(childrenCount == 5){
if(i == 0){
childrenView.layout(r_center - mImageSize, r_center - mImageSize, r_center, r_center);
}else if(i == 1){
childrenView.layout(l_center , r_center - mImageSize, l_center + mImageSize, r_center);
}else{
childrenView.layout(mGap * (i - 1) + mImageSize * (i - 2),t_center,mGap * (i - 1) + mImageSize * (i - 1),t_center+mImageSize);
}
}else if(childrenCount == 6){
if(i < 3) {
childrenView.layout(mGap * (i + 1) +mImageSize * i, b_center - mImageSize, mGap * (i + 1) + mImageSize * (i+1), b_center);
}else{
childrenView.layout(mGap * (i - 2) + mImageSize * (i - 3),t_center,mGap * (i - 2) + mImageSize * (i - 2),t_center+mImageSize);
}
}else if(childrenCount == 7){
if(i == 0){
childrenView.layout(center,mGap,center+mImageSize,mGap+mImageSize);
}else if(i   0 && i < 4){
childrenView.layout(mGap * i +mImageSize * (i - 1),center,mGap * i +mImageSize * i,center+mImageSize);
}else{
childrenView.layout(mGap * (i - 3) + mImageSize * (i - 4),t_center+mImageSize/2,mGap * (i - 3) + mImageSize * (i - 3),t_center+mImageSize/2+mImageSize);
}
}else if(childrenCount == 8){
if(i == 0){
childrenView.layout(r_center - mImageSize,mGap,r_center,mGap+mImageSize);
}else if(i == 1){
childrenView.layout(l_center,mGap,l_center+mImageSize,mGap+mImageSize);
}else if(i   1 && i < 5){
childrenView.layout(mGap * (i - 1) +mImageSize * (i - 2), center, mGap * (i - 1) +mImageSize * (i - 1), center+mImageSize);
}else{
childrenView.layout(mGap * (i - 4) + mImageSize * (i - 5), t_center+mImageSize/2, mGap * (i - 4) + mImageSize * (i - 4), t_center+mImageSize/2+mImageSize);
}
}else if(childrenCount == 9){
childrenView.layout(left, top, right, bottom);
}
}
}
/**
* 设置图片数据
*
* @param lists 图片数据集合
*/
public void setImagesData(List lists){
if(lists == null || lists.isEmpty()){
this.setVisibility(GONE);
return;
}else {
this.setVisibility(VISIBLE);
}
if(mMaxSize   0 && lists.size()   mMaxSize){
lists = lists.subList(0, mMaxSize);
}
int[] gridParam = calculateGridParam(lists.size());
mRowCount = gridParam[0];
mColumnCount = gridParam[1];
if(mImgDataList == null){
int i = 0;
while (i < lists.size()){
ImageView iv = getImageView(i);
if(iv == null){
return;
}
addView(iv,generateDefaultLayoutParams());
i++;
}
}else {
int oldViewCount = mImgDataList.size();
int newViewCount = lists.size();
if(oldViewCount   newViewCount){
removeViews(newViewCount, oldViewCount - newViewCount);
}else if(oldViewCount < newViewCount){
for(int i = oldViewCount; i < newViewCount; i++){
ImageView iv = getImageView(i);
if(iv == null){
return;
}
addView(iv, generateDefaultLayoutParams());
}
}
}
mImgDataList = lists;
requestLayout();
}
/**
* 获得 ImageView
* 保证了 ImageView的重用
*
* @param position 位置
*/
private ImageView getImageView(final int position){
if(position < mImageViewList.size()){
return mImageViewList.get(position);
}else{
if(mAdapter != null){
ImageView imageView = mAdapter.generateImageView(getContext());
mImageViewList.add(imageView);
return imageView;
}else{
Log.e("NineGirdImageView", "Your must set a NineGridImageViewAdapter for NineGirdImageView");
return null;
}
}
}
/**
* 设置宫格参数
*
* @param imagesSize 图片数量
* @return 宫格参数 gridParam[0] 宫格行数 gridParam[1] 宫格列数
*/
protected static int[] calculateGridParam(int imagesSize){
int[] gridParam = new int[2];
if(imagesSize < 3){
gridParam[0] = 1;
gridParam[1] = imagesSize;
}else if(imagesSize <= 4){
gridParam[0] = 2;
gridParam[1] = 2;
}else{
gridParam[0] = imagesSize/3 + (imagesSize % 3 == 0?0:1);
gridParam[1] = 3;
}
return gridParam;
}
/**
* 设置适配器
*
* @param adapter 适配器
*/
public void setAdapter(NineGridImageViewAdapter adapter){
mAdapter = adapter;
}
/**
* 设置宫格间距
*
* @param gap 宫格间距 px
*/
public void setGap(int gap){
mGap = gap;
}
/**
* 对宫格的宽高进行重新定义
*/
private int measureWidth(int measureSpec){
int result = 0;
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);
if(specMode == MeasureSpec.EXACTLY){
result = specSize;
}else{
result = 200;
if(specMode == MeasureSpec.AT_MOST){
result = Math.min(result,specSize);
}
}
return result;
}
private int measureHeight(int measureSpec){
int result = 0;
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);
if(specMode == MeasureSpec.EXACTLY){
result = specSize;
}else{
result = 200;
if(specMode == MeasureSpec.AT_MOST){
result = Math.min(result,specSize);
}
}
return result;
}
}

public abstract class NineGridImageViewAdapter<T  {
protected abstract void onDisplayImage(Context context, ImageView imageView, T t);
protected ImageView generateImageView(Context context){
ImageView imageView = new ImageView(context);
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
return imageView;
}
//这里可以添加你所需要的事件之类的方法
}

<declare-styleable name="NineGridImageView" 
<attr format="dimension" name="imgGap"/ 
</declare-styleable 

NineGridImageViewAdapter<String  mAdapter = new NineGridImageViewAdapter<String () {
@Override
protected void onDisplayImage(Context context, ImageView imageView, String s) {
Picasso.with(context).load(s).placeholder(R.mipmap.ic_holding).error(R.mipmap.ic_error).into(imageView);
}
@Override
protected ImageView generateImageView(Context context) {
return super.generateImageView(context);
}
};
groudIcon1.setAdapter(mAdapter);
groudIcon1.setImagesData(mPostList1);