如今很多应用都提供向外分享信息的功能，在进行分享操作时，一般是从屏幕底部弹出所有具备分享功能的应用列表，再由用户进行选择

现在我就来模仿实现这种效果，不仅使分享控件从屏幕底部弹出，还要使分享控件能够上下拖动，这就需要使用到 design 包提供的 BottomSheetDialog 控件了

首先，声明 BottomSheetDialog 对话框的主布局 dialog_bottom_sheet.xml
当中，RecyclerView 用于展示提供分享功能的应用列表

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="14dp"
    android:orientation="vertical">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="14dp"
        android:text="进一步的说明 -> leavesC"
        android:textAppearance="@style/TextAppearance.AppCompat"
        android:textSize="16sp"/>

    <View
        android:layout_width="match_parent"
        android:layout_height="0.6dp"
        android:background="#ddd"/>

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="12dp"
        android:paddingStart="14dp"
        android:text="分享文本信息到..."
        android:textAppearance="@style/TextAppearance.AppCompat"
        android:textSize="14sp"/>

    <android.support.v7.widget.RecyclerView
        android:id="@+id/rv_appList"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</LinearLayout>

RecyclerView 单个子项使用的布局 item_app.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:paddingBottom="8dp"
    android:paddingLeft="16dp"
    android:paddingRight="16dp"
    android:paddingTop="8dp">

    <ImageView
        android:id="@+id/iv_appIcon"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:scaleType="centerCrop"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:src="@mipmap/ic_launcher"/>

    <TextView
        android:id="@+id/tv_appName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="3dp"
        android:ellipsize="end"
        android:maxLength="6"
        android:textSize="12sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/iv_appIcon"
        tools:text="之乎者也"/>

</android.support.constraint.ConstraintLayout>

RecyclerView 配套使用的 Adapter ：AppShareAdapter

/**
 * 作者：叶应是叶
 * 时间：2018/3/28 20:30
 * 描述：https://github.com/leavesC
 */
public class AppShareAdapter extends RecyclerView.Adapter<AppShareAdapter.ViewHolder> {

    public interface OnClickListener {
        void onClick(int position);
    }

    public interface OnLongClickListener {
        void onLongClick(int position);
    }

    private List<App> appList;

    private LayoutInflater layoutInflater;

    private OnClickListener clickListener;

    private OnLongClickListener longClickListener;

    AppShareAdapter(Context context, List<App> appList) {
        this.layoutInflater = LayoutInflater.from(context);
        this.appList = appList;
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = layoutInflater.inflate(R.layout.item_app, parent, false);
        return new AppShareAdapter.ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(final ViewHolder holder, int position) {
        holder.iv_appIcon.setBackground(appList.get(position).getAppIcon());
        holder.tv_appName.setText(appList.get(position).getAppName());
        holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (clickListener != null) {
                    clickListener.onClick(holder.getAdapterPosition());
                }
            }
        });
        holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                if (longClickListener != null) {
                    longClickListener.onLongClick(holder.getAdapterPosition());
                }
                return true;
            }
        });
    }

    @Override
    public int getItemCount() {
        return appList.size();
    }

    void setClickListener(OnClickListener clickListener) {
        this.clickListener = clickListener;
    }

    void setLongClickListener(OnLongClickListener longClickListener) {
        this.longClickListener = longClickListener;
    }

    class ViewHolder extends RecyclerView.ViewHolder {

        private ImageView iv_appIcon;

        private TextView tv_appName;

        ViewHolder(View itemView) {
            super(itemView);
            iv_appIcon = itemView.findViewById(R.id.iv_appIcon);
            tv_appName = itemView.findViewById(R.id.tv_appName);
        }

    }

}

利用 Intent 找出所有提供分享功能的应用，初始化 BottomSheetDialog 即可

/**
 * 作者：叶应是叶
 * 时间：2018/3/28 20:30
 * 描述：https://github.com/leavesC
 */
public class MainActivity extends AppCompatActivity {

    private List<App> appList;

    private BottomSheetDialog bottomSheetDialog;

    private Intent shareIntent;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        shareIntent = new Intent(Intent.ACTION_SEND);
        shareIntent.setType("text/plain");
        shareIntent.putExtra(Intent.EXTRA_TEXT, "https://github.com/leavesC");
    }

    public void originalShare(View view) {
        Intent intent = Intent.createChooser(shareIntent, "分享一段文本信息");
        if (shareIntent.resolveActivity(getPackageManager()) != null) {
            startActivity(intent);
        }
    }

    public void customizedShare(View view) {
        if (bottomSheetDialog == null) {
            bottomSheetDialog = new BottomSheetDialog(this);
            bottomSheetDialog.setContentView(R.layout.dialog_bottom_sheet);
            initBottomDialog();
        }
        bottomSheetDialog.show();
    }

    private void initBottomDialog() {
        appList = getShareAppList(this, shareIntent);
        AppShareAdapter appShareAdapter = new AppShareAdapter(this, appList);
        appShareAdapter.setClickListener(new AppShareAdapter.OnClickListener() {
            @Override
            public void onClick(int position) {
                Intent intent = new Intent(Intent.ACTION_SEND);
                intent.setComponent(new ComponentName(appList.get(position).getPackageName(), appList.get(position).getMainClassName()));
                intent.setType("text/plain");
                intent.putExtra(Intent.EXTRA_TEXT, "https://github.com/leavesC");
                startActivity(intent);
            }
        });
        appShareAdapter.setLongClickListener(new AppShareAdapter.OnLongClickListener() {
            @Override
            public void onLongClick(int position) {
                Intent intent = new Intent();
                intent.setAction(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
                intent.setData(Uri.parse("package:" + appList.get(position).getPackageName()));
                startActivity(intent);
            }
        });
        RecyclerView rv_appList = bottomSheetDialog.findViewById(R.id.rv_appList);
        if (rv_appList != null) {
            rv_appList.setLayoutManager(new GridLayoutManager(this, 4));
            rv_appList.setAdapter(appShareAdapter);
        }
    }

    public static List<App> getShareAppList(Context context, Intent intent) {
        List<App> appList = new ArrayList<>();
        PackageManager packageManager = context.getPackageManager();
        List<ResolveInfo> resolveInfoList = packageManager.queryIntentActivities(intent, PackageManager.COMPONENT_ENABLED_STATE_DEFAULT);
        if (resolveInfoList == null || resolveInfoList.size() == 0) {
            return null;
        } else {
            for (ResolveInfo resolveInfo : resolveInfoList) {
                App appInfo = new App(resolveInfo.loadLabel(packageManager).toString(), resolveInfo.activityInfo.packageName,
                        resolveInfo.activityInfo.name, resolveInfo.loadIcon(packageManager));
                appList.add(appInfo);
            }
        }
        return appList;
    }

}

这里提供上述示例代码：ShareDialog_Demo

欢迎关注我的 GitHub 账号：leavesC