前言
相信很多朋友在开发中都会遇到图片上传的情况，尤其是多图上传，最经典的莫过于微信的图片选择了。所有很多情况下会使用到多图选择，所以就有了这篇文章，今天抽点时间写了个控件。
•支持自定义选择图片的样式
•支持设置图片选择数量
•支持图片预览，删除
•支持图片拍照
先来看看效果
实现分析
假如不定义控件，我们要实现这样一个功能，无非是写个GridView在item点击的时候去显示图片进行选择，在返回界面的时候进行GridView的数据刷新。我们把这些逻辑写在我们自定义的GridView中，就成了一个新的控件。
1、GridView的效果展示，逻辑实现。
public class ImagePickerView extends GridView{
//图片选择数量
int maxImageSize = 9;
//添加item布局
private int noImgResource;
//列选择数量
private int columnNumber = 3;
Activity context;
ImagesAdapter adapter;
List<String> imageList;//图片选择list
private static final int TYPE_SHOW_ADD = 0;
private static final int TYPE_NO_SHOW_ADD = 1;
private boolean isShowAdd = true;
int imageGridSize;
public void setNoImgResource(int noImgResource) {
this.noImgResource = noImgResource;
}
public void setColumnNumber(int columnNumber) {
if (columnNumber>5){
columnNumber = 5;
}
this.columnNumber = columnNumber;
this.setNumColumns(columnNumber);
}
public void setShowAdd(boolean showAdd) {
isShowAdd = showAdd;
}
public void setImageList(List<String> imageList) {
this.imageList = imageList;
adapter.setImageList(imageList);
}
public List<String> getImageList() {
return imageList;
}
public ImagePickerView(Context context) {
this(context,null);
}
public ImagePickerView(Context context,AttributeSet attrs) {
this(context,attrs,0);
}
/**
* 初始化ImagePickerView的一些信息
* @param context
* @param attrs
* @param defStyle
*/
public ImagePickerView(Context context,AttributeSet attrs,int defStyle) {
super(context,defStyle);
this.context = (Activity) context;
adapter = new ImagesAdapter();
this.setAdapter(adapter);
if (imageList==null){
imageList = new ArrayList<>();
}
this.setNumColumns(columnNumber);
this.setVerticalSpacing(10);
this.setHorizontalSpacing(10);
imageGridSize = (this.context.getWindowManager().getDefaultDisplay().getWidth() - Util.dp2px(context,2) * 2) / columnNumber;
}
/**
* 提供给外部调用用来再Activity返回时获取图片信息
* @param requestCode
* @param resultCode
* @param data
*/
public void onActivityResult(int requestCode,int resultCode,Intent data) {
if (data!=null&& !TextUtils.isEmpty(data.getStringExtra("photoPath"))){//拍照
imageList.add(data.getStringExtra("photoPath"));
}else if (data!=null&&data.getSerializableExtra("images")!=null){//图片选择
imageList = (List<String>) data.getSerializableExtra("images");
}else{
List<ImageItem> list = AndroidImagePicker.getInstance().getSelectedImages();
for (int i=0;i<list.size();i++){
imageList.add(list.get(i).path);
}
}
AndroidImagePicker.getInstance().setSelectLimit(maxImageSize-imageList.size());
adapter.setImageList(imageList);
}
class ImagesAdapter extends BaseAdapter {
List<String> imageList;
public ImagesAdapter() {
this.imageList = new ArrayList();
}
public void setImageList(List<String> imageList) {
this.imageList = imageList;
notifyDataSetChanged();
}
@Override
public int getCount() {
if (isShowAdd){
if (imageList == null || imageList.isEmpty()) {
return 1;
}
if (imageList.size() >= maxImageSize) {
return maxImageSize;
}
return imageList.size() + 1;
}
if (imageList.size() >= maxImageSize) {
return maxImageSize;
}
return imageList.size()+1;
}
@Override
public String getItem(int position) {
if (isShowAdd){
if (position==imageList.size()){
return null;
}
return imageList.get(position-1);
}
return imageList.get(position);
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public int getViewTypeCount() {
return 2;
}
@Override
public int getItemViewType(int position) {
if (isShowAdd){
return position==imageList.size()?TYPE_SHOW_ADD:TYPE_NO_SHOW_ADD;
}else{
return TYPE_NO_SHOW_ADD;
}
}
@Override
public View getView(final int position,View convertView,ViewGroup parent) {
int itemViewType = getItemViewType(position);
if(itemViewType == TYPE_SHOW_ADD){//当前item为添加图片item
if (noImgResource!=0){//加载用户的添加item布局
convertView = LayoutInflater.from(context).inflate(noImgResource,parent,false);
}else {//默认的添加item布局
convertView = LayoutInflater.from(context).inflate(R.layout.grid_item_camera,false);
}
convertView.setTag(null);
convertView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {//点击选择图片
Intent intent = new Intent(context,ImagesGridActivity.class);//图片选择
Activity activity = context;
activity.startActivityForResult(intent,1001);
}
});
}else{//普通item，加载图片，并对item设置点击进行预览
final ViewHolder holder;
if(convertView == null){
convertView = LayoutInflater.from(context).inflate(R.layout.image_grid_item,null);
holder = new ViewHolder();
holder.ivPic = (SimpleDraweeView)convertView.findViewById(R.id.iv_thumb);
holder.cbPanel = convertView.findViewById(R.id.thumb_check_panel);
convertView.setTag(holder);
}else{
holder = (ViewHolder) convertView.getTag();
}
convertView.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {//将选择的图片与当前postion传过去。
Intent intent = new Intent(context,PreviewDelActivity.class);
intent.putExtra("images",(Serializable) imageList);
intent.putExtra("position",position);
context.startActivityForResult(intent,1002);
}
});
ImageRequestBuilder requestBuilder = ImageRequestBuilder.newBuilderWithSource(
Uri.parse(String.format("file://%s",imageList.get(position))))
.setResizeOptions(new ResizeOptions(imageGridSize,imageGridSize))
.setAutoRotateEnabled(true);
PipelineDraweeController controller = (PipelineDraweeController) Fresco.newDraweeControllerBuilder()
.setOldController(holder.ivPic.getController())
.setImageRequest(requestBuilder.build())
.build();
holder.ivPic.setController(controller);
}
return convertView;
}
}
class ViewHolder{
SimpleDraweeView ivPic;
View cbPanel;
}
}
代码比较简单，都加了注释。在view的初始化方法中获取一些信息和GridView的展示信息，并且设置适配器关联。
在GridView的 item中设置了点击事件，并且提供给外部用来刷新数据的onActivityResult方法。
大家看上面的代码应该就明白了。
2、图片预览和删除
这一步很简单，获取到传过来的imageList和postion对图片进行展示，在点击删除的时候remove掉imageList对应的数据，并且刷新viewPager
直接上代码
public class PreviewDelActivity extends AppCompatActivity implements View.OnClickListener {
private static final String TAG = ImagePreviewActivity.class.getSimpleName();
TextView mTitleCount;
TextView mBtnOk;
private ImageView backBtn;
List<String> mImageList;
int mShowItemPosition = 0;
ViewPager mViewPager;
TouchImageAdapter mAdapter ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_preview_del);
mImageList = (List<String>) getIntent().getSerializableExtra("images");
mShowItemPosition = getIntent().getIntExtra("position",0);
mBtnOk = (TextView) findViewById(R.id.btn_del);
backBtn = (ImageView) findViewById(R.id.btn_backpress);
mBtnOk.setOnClickListener(this);
backBtn.setOnClickListener(this);
mTitleCount = (TextView) findViewById(R.id.tv_title_count);
mTitleCount.setText(mShowItemPosition+1+"/" + mImageList.size());// 图片数量和当前图片信息展示
initView();
AndroidImagePicker.getInstance().clearSelectedImages();
}
private void initView() {
mViewPager = (ViewPager)findViewById(R.id.viewpager);
mAdapter = new TouchImageAdapter(getSupportFragmentManager());
mViewPager.setAdapter(mAdapter);
mViewPager.setCurrentItem(mShowItemPosition,false);//设置显示当前的图片
mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position,float positionOffset,int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
mTitleCount.setText(position+1+"/" + mImageList.size());//滑动viewPager时更新显示信息
}
@Override
public void onPageScrollStateChanged(int state) {
}
});
}
@Override
public void onClick(View v) {
int i = v.getId();
if (i == R.id.btn_del) {//删除按钮点击
mAdapter.remove(mViewPager.getCurrentItem());//
mTitleCount.setText(mViewPager.getCurrentItem()+1+"/" + mImageList.size());
if (mImageList.size()==0){
Intent intent = new Intent();
intent.putExtra("images",(Serializable) mImageList);
setResult(RESULT_OK,intent);
finish();
}
}else if (i==R.id.btn_backpress){//返回
Intent intent = new Intent();
intent.putExtra("images",intent);
finish();
}
}
@Override
public boolean onKeyDown(int keyCode,KeyEvent event) {
if (keyCode==KeyEvent.KEYCODE_BACK){
Intent intent = new Intent();
intent.putExtra("images",intent);
finish();
return true;
}
return super.onKeyDown(keyCode,event);
}
class TouchImageAdapter extends FragmentStatePagerAdapter {
public TouchImageAdapter(FragmentManager fm) {
super(fm);
}
@Override
public int getCount() {
return mImageList.size();
}
public void remove(int position){
mImageList.remove(position);
notifyDataSetChanged();
}
@Override
public int getItemPosition(Object object) {
return POSITION_NONE;
}
@Override
public Fragment getItem(int position) {
SinglePreviewFragment fragment = new SinglePreviewFragment();
Bundle bundle = new Bundle();
bundle.putSerializable(SinglePreviewFragment.KEY_URL,mImageList.get(position));
fragment.setArguments(bundle);
return fragment;
}
}
@SuppressLint("ValidFragment")
private class SinglePreviewFragment extends Fragment {
public static final String KEY_URL = "key_url";
private PhotoDraweeView photoDraweeView;
private String url;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Bundle bundle = getArguments();
url = (String) bundle.getSerializable(KEY_URL);
Log.i(TAG,"=====current show image path:" + url);
photoDraweeView = new PhotoDraweeView(getActivity());
photoDraweeView.setBackgroundColor(0xff000000);
ViewGroup.LayoutParams params = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,ViewGroup.LayoutParams.MATCH_PARENT);
photoDraweeView.setLayoutParams(params);
photoDraweeView.setOnPhotoTapListener(new OnPhotoTapListener() {
@Override
public void onPhotoTap(View view,float x,float y) {
getActivity().finish();
}
});
if (!url.startsWith("http://") && !url.startsWith("https://")) {
url = "file://"+url;
}
ImageRequestBuilder requestBuilder = ImageRequestBuilder.newBuilderWithSource(
Uri.parse(url))
.setResizeOptions(new ResizeOptions(768,1280))
.setAutoRotateEnabled(true);
PipelineDraweeControllerBuilder controller = Fresco.newDraweeControllerBuilder();
controller.setOldController(photoDraweeView.getController());
controller.setImageRequest(requestBuilder.build());
controller.setControllerListener(new BaseControllerListener<ImageInfo>() {
@Override
public void onFinalImageSet(String id,ImageInfo imageInfo,Animatable animatable) {
super.onFinalImageSet(id,imageInfo,animatable);
if (imageInfo == null) {
return;
}
photoDraweeView.update(imageInfo.getWidth(),imageInfo.getHeight());
}
});
photoDraweeView.setController(controller.build());
}
@Override
public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) {
return photoDraweeView;
}
}
}
相信大家都能看懂上面代码，用ViewPager对图片进行加载，在点击回退和删除完图片的时候把ImageList传回去。
这样在onActivityResult中获取到imageList，刷新adapter，gridview就重新渲染了。
使用
1、布局中引入ImagePickerView
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" android:orientation="vertical" tools:context="com.qiangyu.test.imagepickerviewdemo.MainActivity"> <com.redare.imagepicker.widget.ImagePickerView android:id="@+id/imagePicker" android:layout_width="match_parent" android:layout_height="wrap_content"> </com.redare.imagepicker.widget.ImagePickerView> <Button android:id="@+id/commit_btn" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="提交"/> </LinearLayout>
2、在Activity中获得ImagePickerView,并且在onActivityResult方法中调用ImagePickerView数据刷新方法
imagePicker.onActivityResult(requestCode,resultCode,data);
3、获取选择图片的路径
调用imagePicker.getImageList()即返回图片选择的List
下面是一段代码示例
public class MainActivity extends AppCompatActivity {
private ImagePickerView imagePicker;
private Button commitBtn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Fresco.initialize(this);
imagePicker = (ImagePickerView) findViewById(R.id.imagePicker);
commitBtn = (Button) findViewById(R.id.commit_btn);
commitBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
for (int i=0;i<imagePicker.getImageList().size();i++){
Log.d("yqy",imagePicker.getImageList().get(i));
}
}
});
imagePicker.setNoImgResource(R.layout.add_img);//自定义imagePicker add item样式
imagePicker.setColumnNumber(5);//设置显示5列
}
@Override
protected void onActivityResult(int requestCode,Intent data) {
imagePicker.onActivityResult(requestCode,data);
}
}
结语
看了ImagePickerView的实现，是不是发现一个自定义控件其实也很简单。在我们做自定义控件的时候，其实大部分情况只是在Android系统提供的功能上多加一点我们的需求而已。站在巨人的肩膀上，才可以看的更远嘛。
关于图片加载和图片选择本文没有提及，图片加载我参考了文章，感兴趣的朋友可以去github查看，https://github.com/easonline/AndroidImagePicker。我在自己的Demo中对源码做了修改，并统一使用了Fresco加载图片。
有需要参考源码的同学请参考：源码下载
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持编程小技巧。
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