RecyclerView+PopupWindow实现下拉选择Spinner

小北编程
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当我们在Android开发中需要实现下拉选择功能时，可以使用自定义的Spinner控件来实现。Spinner控件是一个下拉列表框，可以显示多个选项供用户选择，并在用户选择后显示所选项的文本。

为了方便使用和扩展，我们可以对Spinner进行封装，创建一个自定义的Spinner控件。自定义Spinner可以具备以下特性：

  • 点击展开和收起：通过点击Spinner，可以展开或收起下拉列表框。
  • 自定义样式：可以根据项目需求，自定义Spinner的外观样式，如背景颜色、字体颜色、箭头图标等。
  • 支持数据源：可以传入数据源，将数据显示在下拉列表框中供用户选择。
  • 默认选择项：可以指定一个默认选择项，在下拉列表框展开时，该选项将被高亮显示。
  • 选择监听：可以设置选择监听器，监听用户的选择操作，并进行相应的处理。

通过封装Spinner，我们可以将其功能与外观进行统一管理，并提供更加简洁和易用的接口供其他开发者使用。这样，其他开发者在使用时只需关注数据源和监听回调即可，无需关心Spinner的内部实现细节。

自定义Spinner的封装可以提高代码的可维护性和可复用性，减少重复代码的编写，同时也使代码结构更加清晰和易于理解。

总之，封装Spinner可以帮助我们更高效地实现下拉选择功能，并提供灵活性和可扩展性，使代码更加优雅和易于维护。

图片示例：

WechatIMG53.jpg

2023-07-10 14.03.26.gif

自定义控件封装 定义类CustomSpinner继承LinearLayout以下是示例：

点击展开查看CustomSpinner代码 

package com.example.demo.view;


import android.content.Context;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.PopupWindow;
import android.widget.TextView;




import androidx.annotation.NonNull;
import androidx.core.content.ContextCompat;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;




import com.chad.library.adapter.base.BaseViewHolder;
import com.example.demo.R;




import java.util.Collection;
import java.util.List;




/**







@author: xtxiaolu






@date: 2023/7/7






描述: 自定义公共 下拉选择控件
*/
public class CustomSpinner extends LinearLayout {
private TextView textView;
private ImageView imageView;
private PopupWindow popupWindow;
private List dataList;
private boolean isExpanded = false;
private OnItemSelectedListener itemSelectedListener;




public CustomSpinner(Context context) {
super(context);
init();
}




public CustomSpinner(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}




public CustomSpinner(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}




private void init() {
LayoutInflater.from(getContext()).inflate(R.layout.custom_spinner_layout, this, true);
textView = findViewById(R.id.ll_list_default_txt);
imageView = findViewById(R.id.ll_list_default_icon);



 setClickable(true);
 setOnClickListener(new OnClickListener() {
     @Override
     public void onClick(View v) {
         if (isExpanded) {
             collapse();
         } else {
             expand();
         }
     }
 });




}




public void setData(List dataList) {
this.dataList = dataList;
}




/**




刷新页面

@param data
*/
public void replaceData(@NonNull Collection<? extends T> data) {
// 不是同一个引用才清空列表
if (data != dataList) {
dataList.clear();
dataList.addAll(data);
}
}




public void setTextViewValue(String value) {
textView.setText(value);
}




public TextView getTextViewValue() {
return textView;
}




private void expand() {
if (dataList == null || dataList.isEmpty()) {
return;
}



 textView.setTextColor(ContextCompat.getColor(getContext(), R.color.text_order_black));
 imageView.setImageResource(R.drawable.expand_arrows_fold);

 View popupView = LayoutInflater.from(getContext()).inflate(R.layout.popup_selector, null);
 RecyclerView recyclerView = popupView.findViewById(R.id.recyclerView);
 recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));

 CustomAdapter popAdapter = new CustomAdapter<>(R.layout.item_listview_popwin, dataList);
 popAdapter.setSelectedPosition(0);
 popAdapter.setOnItemClickListener(new CustomAdapter.OnItemClickListener() {
     @Override
     public void onItemClick(int position) {
         T selectedItem = dataList.get(position);
         if (itemSelectedListener != null) {
             itemSelectedListener.onItemSelected(position, selectedItem);
         }
         popupWindow.dismiss();
     }

     @Override
     public void convertView(BaseViewHolder holder, Object item, boolean isSelected) {
         if (itemSelectedListener != null) {
             itemSelectedListener.onItemCallBackData(holder, item);
         }
     }
 });
 recyclerView.setAdapter(popAdapter);

 int width = ViewGroup.LayoutParams.MATCH_PARENT;
 int height = ViewGroup.LayoutParams.WRAP_CONTENT;
 popupWindow = new PopupWindow(popupView, width, height);
 popupWindow.setBackgroundDrawable(new ColorDrawable(Color.WHITE));
 popupWindow.setFocusable(true);
 popupWindow.setOutsideTouchable(true);
 popupWindow.setOnDismissListener(new PopupWindow.OnDismissListener() {
     @Override
     public void onDismiss() {
         collapse();
     }
 });

 int[] location = new int[2];
 getLocationOnScreen(location);
 int x = location[0];
 int y = location[1] + getHeight();
 popupWindow.showAtLocation(this, Gravity.NO_GRAVITY, x, y);

 isExpanded = true;




}




private void collapse() {
textView.setTextColor(ContextCompat.getColor(getContext(), R.color.colorTextBlue));
imageView.setImageResource(R.drawable.expand_arrows_unfold);



 if (popupWindow != null && popupWindow.isShowing()) {
     popupWindow.dismiss();
 }

 isExpanded = false;




}




public void setOnItemSelectedListener(OnItemSelectedListener listener) {
this.itemSelectedListener = listener;
}




public interface OnItemSelectedListener {
void onItemSelected(int position, Object item);
void onItemCallBackData(BaseViewHolder holder, Object item);
}
} 
    

  • 

    @author: xtxiaolu
    

    • 

  • 

    @date: 2023/7/7
    

    • 

  • 

    描述: 自定义公共 下拉选择控件
*/
public class CustomSpinner extends LinearLayout {
private TextView textView;
private ImageView imageView;
private PopupWindow popupWindow;
private List dataList;
private boolean isExpanded = false;
private OnItemSelectedListener itemSelectedListener;
    

    public CustomSpinner(Context context) {
super(context);
init();
}
    

    public CustomSpinner(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
    

    public CustomSpinner(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
    

    private void init() {
LayoutInflater.from(getContext()).inflate(R.layout.custom_spinner_layout, this, true);
textView = findViewById(R.id.ll_list_default_txt);
imageView = findViewById(R.id.ll_list_default_icon);
    

     setClickable(true);
 setOnClickListener(new OnClickListener() {
     @Override
     public void onClick(View v) {
         if (isExpanded) {
             collapse();
         } else {
             expand();
         }
     }
 });

    

    }
    

    public void setData(List dataList) {
this.dataList = dataList;
}
    

    /**
    

      

    • 刷新页面
      • 

    • 

    • @param data
*/
public void replaceData(@NonNull Collection<? extends T> data) {
// 不是同一个引用才清空列表
if (data != dataList) {
dataList.clear();
dataList.addAll(data);
}
}
      • 

    

    public void setTextViewValue(String value) {
textView.setText(value);
}
    

    public TextView getTextViewValue() {
return textView;
}
    

    private void expand() {
if (dataList == null || dataList.isEmpty()) {
return;
}
    

     textView.setTextColor(ContextCompat.getColor(getContext(), R.color.text_order_black));
 imageView.setImageResource(R.drawable.expand_arrows_fold);

 View popupView = LayoutInflater.from(getContext()).inflate(R.layout.popup_selector, null);
 RecyclerView recyclerView = popupView.findViewById(R.id.recyclerView);
 recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));

 CustomAdapter popAdapter = new CustomAdapter<>(R.layout.item_listview_popwin, dataList);
 popAdapter.setSelectedPosition(0);
 popAdapter.setOnItemClickListener(new CustomAdapter.OnItemClickListener() {
     @Override
     public void onItemClick(int position) {
         T selectedItem = dataList.get(position);
         if (itemSelectedListener != null) {
             itemSelectedListener.onItemSelected(position, selectedItem);
         }
         popupWindow.dismiss();
     }

     @Override
     public void convertView(BaseViewHolder holder, Object item, boolean isSelected) {
         if (itemSelectedListener != null) {
             itemSelectedListener.onItemCallBackData(holder, item);
         }
     }
 });
 recyclerView.setAdapter(popAdapter);

 int width = ViewGroup.LayoutParams.MATCH_PARENT;
 int height = ViewGroup.LayoutParams.WRAP_CONTENT;
 popupWindow = new PopupWindow(popupView, width, height);
 popupWindow.setBackgroundDrawable(new ColorDrawable(Color.WHITE));
 popupWindow.setFocusable(true);
 popupWindow.setOutsideTouchable(true);
 popupWindow.setOnDismissListener(new PopupWindow.OnDismissListener() {
     @Override
     public void onDismiss() {
         collapse();
     }
 });

 int[] location = new int[2];
 getLocationOnScreen(location);
 int x = location[0];
 int y = location[1] + getHeight();
 popupWindow.showAtLocation(this, Gravity.NO_GRAVITY, x, y);

 isExpanded = true;

    

    }
    

    private void collapse() {
textView.setTextColor(ContextCompat.getColor(getContext(), R.color.colorTextBlue));
imageView.setImageResource(R.drawable.expand_arrows_unfold);
    

     if (popupWindow != null && popupWindow.isShowing()) {
     popupWindow.dismiss();
 }

 isExpanded = false;

    

    }
    

    public void setOnItemSelectedListener(OnItemSelectedListener listener) {
this.itemSelectedListener = listener;
}
    

    public interface OnItemSelectedListener {
void onItemSelected(int position, Object item);
void onItemCallBackData(BaseViewHolder holder, Object item);
}
}

上面是控件代码 下面是适配器代码都是使用范型来传输数据这样方便通用！

展开查看CustomAdapter 

package com.example.demo.view;


import android.view.View;




import androidx.annotation.LayoutRes;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;




import com.chad.library.adapter.base.BaseQuickAdapter;
import com.chad.library.adapter.base.BaseViewHolder;




import java.util.List;




/**







@author: xtxiaolu






@date: 2023/7/7






描述:
*/
public class CustomAdapter extends BaseQuickAdapter<T, BaseViewHolder> {
private int selectedPosition = -1;
private OnItemClickListener itemClickListener;




public CustomAdapter(@LayoutRes int layoutResId, @Nullable List data) {
super(layoutResId, data);
}




public void setSelectedPosition(int position) {
this.selectedPosition = position;
notifyDataSetChanged();
}




public void setOnItemClickListener(OnItemClickListener listener) {
this.itemClickListener = listener;
}




@Override
protected void convert(BaseViewHolder holder, T item) {
if (itemClickListener != null) {
itemClickListener.convertView(holder, item, selectedPosition == holder.getBindingAdapterPosition());
}
}




@Override
public void onBindViewHolder(@NonNull BaseViewHolder holder, int position) {
super.onBindViewHolder(holder, position);
holder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (itemClickListener != null) {
itemClickListener.onItemClick(holder.getBindingAdapterPosition());
}
}
});
}




public interface OnItemClickListener {
void onItemClick(int position);



 void convertView(BaseViewHolder holder, Object item, boolean isSelected);




}
}

如果本文对您有所帮助请点赞收藏给予支持，谢谢有您的支持我将不惜再接再厉！

下面是代码链接：gitee.com/xtxiaolu/Xi…

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