Android GridView仿微信添加多图效果

 <GridView  android:id="@+id/gridView"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:columnWidth="90dp"  android:gravity="center"  android:horizontalSpacing="4dp"  android:numColumns="3"  android:scrollbars="none"  android:stretchMode="columnWidth"  android:verticalSpacing="4dp" />

 //图片数据，ImageItem是图片选择的库自带的Bean private ArrayList<ImageItem> images; //adapter是核心，添加按钮的处理删除的处理都在里面，后面会说，别急 private MultiImageAdapter adapter; //初次进入的时候先只传this adapter = new MultiImageAdapter(this); gridView.setAdapter(adapter); @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) {  super.onActivityResult(requestCode, resultCode, data);  if (data != null && requestCode == 3) {   //判断一下是否有数据，有的话就addAll()，不会覆盖已经有的图   if(images == null){    images = (ArrayList<ImageItem>)      data.getSerializableExtra(ImagePicker.EXTRA_RESULT_ITEMS);   }else{    images.addAll((ArrayList<ImageItem>)      data.getSerializableExtra(ImagePicker.EXTRA_RESULT_ITEMS));   }   //拿到图片数据后把images传过去   adapter = new MultiImageAdapter(this,images);   gridView.setAdapter(adapter);  } else {   Toast.makeText(this, "没有选择图片", Toast.LENGTH_SHORT).show();  } }

 <?xml version="1.0" encoding="utf-8"?> <com.anfq.mylibrary.view.SquareLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="match_parent"  android:background="#ffffff"  android:layout_height="match_parent">  <RelativeLayout   android:layout_width="match_parent"   android:layout_height="wrap_content">   <ImageView    android:id="@+id/ivIcon"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:background="@color/colorPrimaryDark"    android:scaleType="fitXY" />   <ImageButton    android:id="@+id/ibDelete"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_alignParentEnd="true"    android:layout_alignParentRight="true"    android:layout_alignParentTop="true"    android:background="@null"    android:padding="10dp"    android:src="@drawable/del" />  </RelativeLayout>  <ImageButton   android:id="@+id/ibAdd"   android:layout_width="match_parent"   android:layout_height="match_parent"   android:layout_centerInParent="true"   android:background="#eeeeee"   android:src="@drawable/add"   android:visibility="gone" /> </com.anfq.mylibrary.view.SquareLayout>

 public class SquareLayout extends RelativeLayout {  public SquareLayout(Context context, AttributeSet attrs, int defStyle) {   super(context, attrs, defStyle);  }  public SquareLayout(Context context, AttributeSet attrs) {   super(context, attrs);  }  public SquareLayout(Context context) {   super(context);  }  @SuppressWarnings("unused")  @Override  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {   setMeasuredDimension(getDefaultSize(0, widthMeasureSpec),     getDefaultSize(0, heightMeasureSpec));   int childWidthSize = getMeasuredWidth();   int childHeightSize = getMeasuredHeight();   // 高度和宽度一样   heightMeasureSpec = widthMeasureSpec = MeasureSpec.makeMeasureSpec(     childWidthSize, MeasureSpec.EXACTLY);   super.onMeasure(widthMeasureSpec, heightMeasureSpec);  } }

 public class MultiImageAdapter extends BaseAdapter {  private Activity activity;  private LayoutInflater inflater;  private ArrayList<ImageItem> mImages;  //用来判断是否是刚刚进入，刚进入只显示添加按钮，也就是上面java代码中只传this的时候  private boolean is = false;  ImagePicker imagePicker = ImagePicker.getInstance();  public MultiImageAdapter(Activity activity, ArrayList<ImageItem> images) {   this.activity = activity;   this.inflater = LayoutInflater.from(activity);   this.mImages = images;   initImagePicker();//设置图片选择的一些属性  } public MultiImageAdapter(Activity activity) {   this.activity = activity;   this.inflater = LayoutInflater.from(activity);   is = true;//设置为true表示第一次初始化   initImagePicker();//设置图片选择的一些属性  }  @Override  public int getCount() {   if(!is){    //这里判断数据如果有9张就size等于9,否则就+1，+1是为按钮留的位置    return mImages.size()==9?mImages.size():mImages.size()+1;   }   //没有数据就是1，1是为按钮留的位置   return 1;  }  @Override  public Object getItem(int position) {   return mImages.get(position);  }  @Override  public long getItemId(int position) {   return position;  }  @Override  public View getView(final int position, View view, final ViewGroup parent) {   ViewHolder holder = null;   if (null == view) {    view = inflater.inflate(R.layout.item_ulti_image, null);    holder = new ViewHolder();    holder.ivIcon = (ImageView) view.findViewById(R.id.ivIcon);    holder.ibAdd = (ImageButton) view.findViewById(R.id.ibAdd);    holder.ibDelete = (ImageButton) view.findViewById(R.id.ibDelete);    view.setTag(holder);   } else {    holder = (ViewHolder) view.getTag();   }   if(!is){    //选了图片后会进入这里，先判断下position 是否等于size    if(position == mImages.size()){     //执行到这里就说明是最后一个位置，判断是否有9张图     if(mImages.size() != 9){      //没有9张图就显示添加按钮      holder.ibAdd.setVisibility(View.VISIBLE);     }else{      //有就隐藏      holder.ibAdd.setVisibility(View.GONE);     }    }else{     //还不是最后一个位置的时候执行这里     //隐藏添加按钮，要设置图片嘛~     holder.ibAdd.setVisibility(View.GONE);     //根据条目位置设置图片     ImageItem item = mImages.get(position);     Glide.with(activity)       .load(item.path)       .into(holder.ivIcon);    }    //删除按钮的点击事件    holder.ibDelete.setOnClickListener(new View.OnClickListener() {     @Override     public void onClick(View v) {      //移除图片      mImages.remove(position);      //更新      notifyDataSetChanged();     }    });   }else{    //初次初始化的时候显示添加按钮    holder.ibAdd.setVisibility(View.VISIBLE);   }   //添加按钮点击事件   holder.ibAdd.setOnClickListener(new View.OnClickListener() {    @Override    public void onClick(View v) {     //判断是否是初始化进入     if(!is){      //到这里表示已经选过了，然后用9-size算出还剩几个图的位置      imagePicker.setSelectLimit(9-mImages.size());//选中数量限制     }     //跳转到图片选择     Intent intent = new Intent(activity, ImageGridActivity.class);     activity.startActivityForResult(intent, 3);    }   });   return view;  }  protected class ViewHolder {   /** icon */   protected ImageView ivIcon;   /** 移除 */   protected ImageButton ibDelete;   /**添加 */   protected ImageButton ibAdd;  }  private void initImagePicker() {   imagePicker.setImageLoader(new GlideImageLoader()); //设置图片加载器   imagePicker.setShowCamera(true);//显示拍照按钮   imagePicker.setCrop(true);//允许裁剪（单选才有效）   imagePicker.setSaveRectangle(true);//是否按矩形区域保存   imagePicker.setSelectLimit(9);//选中数量限制   imagePicker.setStyle(CropImageView.Style.CIRCLE);//裁剪框的形状   imagePicker.setFocusWidth(100);//裁剪框的宽度。单位像素（圆形自动取宽高最小值）   imagePicker.setFocusHeight(100);//裁剪框的高度。单位像素（圆形自动取宽高最小值）   imagePicker.setOutPutX(1000);//保存文件的宽度。单位像素   imagePicker.setOutPutY(1000);//保存文件的高度。单位像素  } }