RecyclerView載入不同item並實現其item點選事件，實現新增常用應用的功能
阿新 • • 發佈：2019-02-19
先上效果圖吧
勾選需要的應用
這裡出現了三種item的樣式，一種是加號，一種是應用圖示加文字，最後一種是應用圖示加文字還有個checkBox
這裡RecyclerView是配合CardView使用的。
在AS中使用RecyclerView需要先在build.gradle中新增依賴
dependencies { compile fileTree(dir: 'libs', include: ['*.jar']) testCompile 'junit:junit:4.12' compile 'com.android.support:appcompat-v7:23.4.0' compile 'com.android.support:recyclerview-v7:23.4.0' compile 'com.android.support:cardview-v7:23.4.0' }
佈局檔案：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <TextView android:id="@+id/tv_sys" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginLeft="@dimen/five" android:text="@string/systems_apps" /> <android.support.v7.widget.RecyclerView android:id="@+id/recycleView" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_below="@+id/tv_sys" /> </RelativeLayout>
三種item的佈局：
card_plus.xml 加號的佈局
<?xml version="1.0" encoding="utf-8"?> <android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="@dimen/two" android:layout_marginLeft="@dimen/five" android:layout_marginRight="@dimen/five" android:layout_marginTop="@dimen/two"> <RelativeLayout android:layout_width="match_parent" android:layout_height="match_parent"> <ImageView android:id="@+id/img_plus_card" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerInParent="true" android:src="@mipmap/jia_128" /> </RelativeLayout> </android.support.v7.widget.CardView>
card_no_check.xml 沒有checkBox的item佈局
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="@dimen/hundred_ten"
android:layout_marginBottom="@dimen/two"
android:layout_marginLeft="@dimen/five"
android:layout_marginRight="@dimen/five"
android:layout_marginTop="@dimen/two">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerInParent="true">
<ImageView
android:id="@+id/img_card"
android:layout_width="@dimen/fifty"
android:layout_height="@dimen/fifty"
android:layout_centerHorizontal="true"
android:layout_marginTop="@dimen/five"
android:src="@mipmap/ic_launcher" />
<TextView
android:id="@+id/tv_card"
android:layout_width="wrap_content"
android:layout_height="@dimen/sixty"
android:layout_below="@id/img_card"
android:layout_centerHorizontal="true"
android:ellipsize="end"
android:gravity="center"
android:maxLength="25"
android:text="icon1"
android:textColor="@android:color/black"
android:textSize="@dimen/font_s" />
</RelativeLayout>
</android.support.v7.widget.CardView><?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="@dimen/hundred_ten"
android:layout_marginBottom="@dimen/two"
android:layout_marginLeft="@dimen/five"
android:layout_marginRight="@dimen/five"
android:layout_marginTop="@dimen/two">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerInParent="true">
<ImageView
android:id="@+id/img_card2"
android:layout_width="@dimen/fifty"
android:layout_height="@dimen/fifty"
android:layout_centerHorizontal="true"
android:layout_marginTop="@dimen/five"
android:src="@mipmap/ic_launcher" />
<CheckBox
android:id="@+id/checkbox_card2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="@dimen/ten"
android:layout_marginTop="@dimen/five"
android:background="@drawable/checkbox_style"
android:button="@null" />
<TextView
android:id="@+id/tv_card2"
android:layout_width="wrap_content"
android:layout_height="@dimen/sixty"
android:layout_below="@id/img_card2"
android:layout_centerHorizontal="true"
android:ellipsize="end"
android:gravity="center"
android:maxLength="25"
android:text="icon1"
android:textColor="@android:color/black"
android:textSize="@dimen/font_s" />
</RelativeLayout>
</android.support.v7.widget.CardView>重點就在Adapter裡面了，RecyclerView繼承的是RecyclerView.Adapter<>
因為這裡主要是要載入三種不同的item
所以要重寫getItemViewType(int position)方法，以決定元素的佈局使用哪種型別。由於有三種item，所以也要寫三個ViewHolder，繼承RecyclerView.ViewHolder.另外還要重寫的方法有onCreateViewHolder()用於渲染具體的ViewHolder，onBindViewHolder用於繫結ViewHolder的資料。
RecyclerViewAdapter.java
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> implements View.OnClickListener {
private List<PackageMessage> mList;
private PackagePreference mPreference;
private OnRecyclerViewItemClickListener mListener;
private static int mFlag;
public final static int NO_CHECK = 0;
public final static int CHECK = 1;
public final static int PLUS = 2;
public RecyclerViewAdapter(List<PackageMessage> list, int flag) {
this.mList = list;
this.mFlag = flag;
mPreference = PackagePreference.getInstance(MyApplication.getContext());
}
/**
* 渲染具體的ViewHolder
*
* @param parent ViewHolder的容器
* @param viewType 根據該標誌實現渲染不同型別的ViewHolder
* @return
*/
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
//載入資料item的佈局，生成VH返回
if (viewType == NO_CHECK) {
return new NoCheckViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.card_no_check, parent, false));
} else if (viewType == CHECK) {
return new CheckViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.card_check, parent, false));
} else if (viewType == PLUS) {
return new PlusViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.card_plus, parent, false));
} else {
return null;
}
}
/**
* 繫結ViewHolder的資料
*
* @param holder
* @param position
*/
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
PackageMessage message = mList.get(position);
//資料繫結
if (holder instanceof NoCheckViewHolder) {
bindNoCheckViewHolder(message, (NoCheckViewHolder) holder);
} else if (holder instanceof CheckViewHolder) {
bindCheckViewHolder(message, (CheckViewHolder) holder);
}
holder.itemView.setTag(position);
holder.itemView.setOnClickListener(this);
}
@Override
public int getItemCount() {
if (null == mList) {
return 0;
}
return mList.size();
}
/**
* 決定元素的佈局使用哪種型別
*
* @param position
* @return 傳遞給onCreateViewHolder的第二個引數
*/
@Override
public int getItemViewType(int position) {
if (mFlag == NO_CHECK) {
if (position == mList.size() - 1) {
return PLUS;
}
return NO_CHECK;
} else if (mFlag == CHECK) {
return CHECK;
} else {
return 100;
}
}
private void bindNoCheckViewHolder(PackageMessage message, NoCheckViewHolder holder) {
holder.tv.setText(message.getLabel());
holder.img.setImageDrawable(message.getIcon());
}
private void bindCheckViewHolder(PackageMessage message, final CheckViewHolder holder) {
holder.tv2.setText(message.getLabel());
holder.img2.setImageDrawable(message.getIcon());
final String packageName = message.getPackageName();
holder.checkBox2.setChecked(mPreference.getPackageMessage(packageName));
holder.checkBox2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (holder.checkBox2.isChecked()) {
mPreference.putPackageMessage(packageName, true);
} else {
mPreference.putPackageMessage(packageName, false);
}
}
});
}
public static class NoCheckViewHolder extends RecyclerView.ViewHolder {
public ImageView img;
public TextView tv;
public NoCheckViewHolder(View itemView) {
super(itemView);
img = (ImageView) itemView.findViewById(R.id.img_card);
tv = (TextView) itemView.findViewById(R.id.tv_card);
}
}
public static class CheckViewHolder extends RecyclerView.ViewHolder {
public CheckBox checkBox2;
public ImageView img2;
public TextView tv2;
public CheckViewHolder(View itemView) {
super(itemView);
checkBox2 = (CheckBox) itemView.findViewById(R.id.checkbox_card2);
img2 = (ImageView) itemView.findViewById(R.id.img_card2);
tv2 = (TextView) itemView.findViewById(R.id.tv_card2);
}
}
public static class PlusViewHolder extends RecyclerView.ViewHolder {
public ImageView img_plus_card;
public PlusViewHolder(View itemView) {
super(itemView);
img_plus_card = (ImageView) itemView.findViewById(R.id.img_plus_card);
}
}
@Override
public void onClick(View v) {
if (null != mListener) {
mListener.onItemClick(v, (Integer) v.getTag());
}
}
public void setOnItemClickListener(OnRecyclerViewItemClickListener listener) {
this.mListener = listener;
}
public interface OnRecyclerViewItemClickListener {
void onItemClick(View view, int position);
}
}由於RecyclerView沒有item的點選事件，所以此處在Adapter裡面新增item的點選事件，定義一個介面OnRecyclerViewItemClickListener，寫一個抽象方法onItemClick(View view,int position)把當前item的position設定進去，在onBindView裡面監聽item的點選事件。
Activity或Fragment呼叫處：
我這裡是使用的網格佈局，所以例項化網格佈局管理器GridLayoutManager,如果是線性佈局，則例項化LinearLayoutManager
在例項化RecyclerViewAdapter的時候，將item的型別傳過去
//線性佈局管理器
// LinearLayoutManager llManager = new LinearLayoutManager(mContext);
GridLayoutManager glManager = new GridLayoutManager(mContext, 4);
//設定佈局管理器
mRecyclerView.setLayoutManager(glManager);
mRecyclerView.setHasFixedSize(true); //每個選項高度固定
mRecyclerView.setItemAnimator(new DefaultItemAnimator());
mAdapter = new RecyclerViewAdapter(mCheckedList, RecyclerViewAdapter.NO_CHECK);
mAdapter.setOnItemClickListener(this);
mRecyclerView.setAdapter(mAdapter);
實現RecyclerViewAdapter.OnRecyclerViewItemClickListener，點選最後一個item(加號)的時候跳轉到另一個Activity
@Override
public void onItemClick(View view, int position) {
if (position == (mCheckedList.size() - 1)) {
startActivityForResult(new Intent(getActivity(), ListActivity2.class), 1);
}
}下面說下這個demo的資料儲存等
先獲取系統安裝了的應用資訊
在Application裡
MyApplication.java
public class MyApplication extends Application {
private static Context mContext;
private PackageManager mPackageManager;
private List<PackageInfo> mPackageInfoList;
private ApplicationInfo mApplicationInfo;
private static List<PackageMessage> mPackList;
@Override
public void onCreate() {
super.onCreate();
mContext = getApplicationContext();
mPackageManager = getPackageManager();
mPackageInfoList = mPackageManager.getInstalledPackages(0);
getPackageMessage();
}
public static Context getContext() {
return mContext;
}
/**
* 得到應用的包名並存儲
*/
private void getPackageMessage() {
List<PackageInfo> systemApps = new ArrayList<>();
for (PackageInfo apps : mPackageInfoList) {
if ((apps.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) > 0) {
//獲取系統應用
systemApps.add(apps);
}
}
int size = systemApps.size();
mPackList = new ArrayList<>();
PackageMessage message;
for (int i = 0; i < size; i++) {
message = new PackageMessage();
PackageInfo packageInfo = systemApps.get(i);
mApplicationInfo = packageInfo.applicationInfo;
String packageName = mApplicationInfo.packageName;
Drawable drawable = mPackageManager.getApplicationIcon(mApplicationInfo);
String label = (String) mPackageManager.getApplicationLabel(mApplicationInfo);
message.setIcon(drawable);
message.setLabel(label);
message.setPackageName(packageName);
mPackList.add(message);
}
}
public static List<PackageMessage> getmPackList() {
return mPackList;
}
}public class PackageMessage {
private String packageName; //包名
private Drawable icon; //圖示
private String label; //名稱
private boolean isChecked; //是否選中
public String getPackageName() {
return packageName;
}
public void setPackageName(String packageName) {
this.packageName = packageName;
}
public Drawable getIcon() {
return icon;
}
public void setIcon(Drawable icon) {
this.icon = icon;
}
public String getLabel() {
return label;
}
public void setLabel(String label) {
this.label = label;
}
public boolean isChecked() {
return isChecked;
}
public void setIsChecked(boolean isChecked) {
this.isChecked = isChecked;
}
}最先出現的RecyclerVIew的Fragment
Fragment2.java
public class Fragment2 extends Fragment implements RecyclerViewAdapter.OnRecyclerViewItemClickListener {
private View mView;
private RecyclerView mRecyclerView;
private List<PackageMessage> mPackList; //全部的應用的資訊列表
private List<PackageMessage> mCheckedList; //已經被選中的應用列表
private RecyclerViewAdapter mAdapter;
private Context mContext;
private PackagePreference mPreference;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
mView = inflater.inflate(R.layout.fragment2, container, false);
mRecyclerView = (RecyclerView) mView.findViewById(R.id.recycleView);
return mView;
}
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
//線性佈局管理器
// LinearLayoutManager llManager = new LinearLayoutManager(mContext);
GridLayoutManager glManager = new GridLayoutManager(mContext, 4);
//設定佈局管理器
mRecyclerView.setLayoutManager(glManager);
mRecyclerView.setHasFixedSize(true); //每個選項高度固定
mRecyclerView.setItemAnimator(new DefaultItemAnimator());
mContext = MyApplication.getContext();
mPreference = PackagePreference.getInstance(mContext);
mPackList = MyApplication.getmPackList();
showCheckedList();
}
@Override
public void onItemClick(View view, int position) {
if (position == (mCheckedList.size() - 1)) {
startActivityForResult(new Intent(getActivity(), ListActivity2.class), 1);
}
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 1 && resultCode == 2) {
showCheckedList();
}
}
private void showCheckedList() {
mCheckedList = new ArrayList<>();
String[] names = mPreference.getAllCheckedPackageNames();
for (int i = 0; i < names.length; i++) {
for (int j = 0; j < mPackList.size(); j++) {
if (names[i].equals(mPackList.get(j).getPackageName())) {
mCheckedList.add(mPackList.get(j));
break;
}
}
}
PackageMessage m = new PackageMessage();
mCheckedList.add(m);
mAdapter = new RecyclerViewAdapter(mCheckedList, RecyclerViewAdapter.NO_CHECK);
mAdapter.setOnItemClickListener(this);
mRecyclerView.setAdapter(mAdapter);
}
}
這裡採用SharedPreference來儲存系統中安裝的應用包名，key為包名，value為是否選中。另定義了一個字串來儲存已經選中的應用的包名。
PackagePreference.java
public class PackagePreference {
private String PREFS_CHECKED_NAME = "CheckedPackageName";
private Context mContext;
private static PackagePreference mPackagePreference;
private SharedPreferences mSp;
private SharedPreferences.Editor mEditor;
private String TAG = "PackagePreference";
private StringBuilder mCheckedPackageName;
private PackagePreference(Context context) {
this.mContext = context;
mSp = context.getSharedPreferences("checkedPackage", Context.MODE_PRIVATE);
mEditor = mSp.edit();
}
public static PackagePreference getInstance(Context context) {
if (mPackagePreference == null) {
mPackagePreference = new PackagePreference(context);
}
return mPackagePreference;
}
/**
* 將應用的包名和是否被選中放進去
*/
public void putPackageMessage(String packageName, boolean isChecked) {
mEditor.putBoolean(packageName, isChecked).commit();
String name = getCheckedPackageName();
mCheckedPackageName = new StringBuilder(name);
if (isChecked) {
mCheckedPackageName.append(packageName).append(",");
} else {
int index = mCheckedPackageName.indexOf(packageName);
mCheckedPackageName.delete(index, index + packageName.length() + 1);
}
putCheckedPackageName();
}
public void putCheckedPackageName() {
mEditor.putString(PREFS_CHECKED_NAME, mCheckedPackageName.toString()).commit();
}
public String getCheckedPackageName() {
return mSp.getString(PREFS_CHECKED_NAME, "");
}
/**
* 通過包名得知是否被選中
*
* @param packageName
*/
public boolean getPackageMessage(String packageName) {
return mSp.getBoolean(packageName, false);
}
/**
* 得到所有選中的應用名陣列
*
* @return
*/
public String[] getAllCheckedPackageNames() {
String name = getCheckedPackageName();
String[] names = name.split(",");
return names;
}
}