Android解决ListView中getView()多次调用的问题

「这是我参与11月更文挑战的第5天,活动详情查看:2021最后一次更文挑战」 在做Dialog突然发现一个奇怪的现象,就是在在定义的listview中有一个textview和一个switch,但是使用listview的时候,同一个switch的状态会不断的变化。

解决方法

方法一:

在listview外面套一层RelativeLayout,将listview高度设置为match_parent。

方法二:

在listview外面套一层 LinearLayout,将listview高度设置为0dp weight设为1

很显然高度设置为match_parent放在dialog不合适

我是在ListView中嵌套Switch开关,点击ListView条目来切换Switch的状态,用List来控制,所以要在getView()中加入

于是在adapter中进行打点发现 image.png 6个条目刷新了42次
3个条目刷新了21次
所以getView()一共调用了7次

这时候问题来了,调用了这么多次,到底要在哪一次加呢?

一个一个分析发现 6组数据
1组:0
2组: 25 = (7-3)×6+1
3组: 26 = (7-3)×6+2
4组: 27 = (7-3)×6+3
5组: 28 = (7-3)×6+4
6组: 29 = (7-3)×6+5

所以:7-3=4 是第4次。

方法三:

int List_Count = getCount();
            int aa = List_Count * 4 + 1;
            
            int_list_switch = new int[List_Count];

        
            for (int i = 0; i < List_Count; i++) {

                int_list_switch[i] = aa;
                aa++;
            }


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getView()中

     //优化Switch控件
            if (Optimize_getView == 0) {
                list_switch.add(holder.sw_Clock);
            }
            if (Optimize_getView == int_list_switch[Optimize_getView_Assist]) {
                list_switch.add(holder.sw_Clock);
                Log.d("添加switch", "" + Optimize_getView);
                if (list_switch.size() < getCount())
                    Optimize_getView_Assist++;
            }

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不放图的一律当水贴处理

1fe7eb17cc0401d135b0f8d1029ef90.jpg 觉得还有什么更好的办法评论下方留意吧!

全部代码

    class TalkAdapter extends BaseAdapter implements OnClickListener {

        private Context mContext;
        private List<Course>  mData;
        private List<Switch> list_switch;


        private int[] int_list_switch;
        private int Optimize_getView = 0;
        private int Optimize_getView_Assist =0;
        public HashMap<Integer, Boolean> Switch_isSelected= new HashMap<Integer, Boolean>();


        public TalkAdapter(Context mContext, List<Course>  mData) {
            this.mData = mData;
            this.mContext = mContext;


            list_switch = new ArrayList<>();
            list_switch.clear();

            int List_Count = getCount();
            int aa = List_Count * 4 + 1;
            int bb = 1;
            int_list_switch = new int[List_Count];

        
            for (int i = 0; i < List_Count; i++) {

                int_list_switch[i] = aa;
                aa++;
            }

            // int_list_switch= new int[]{0,17,18,19,28,29};


            if (MMkvListDate.isDataCapacity(SwitchStatus_KEY)) {              
                Switch_isSelected.clear();
                Switch_isSelected = MMkvListDate.getIBHashMap(SwitchStatus_KEY);             
            } else {
                for (int i = 0; i < getCount(); i++) {
                    Switch_isSelected.put(i, false);

                }
            }
        }

        public Switch getaSwitch(int position) {
            // Toast.makeText(mContext,list_switch.size()+ "位置:"+position, Toast.LENGTH_SHORT).show();
            return list_switch.get(position);
        }

        @Override
        public int getCount() {          
            return mData.size();
        }

        @Override
        public Object getItem(int position) {
            return mData.get(position);
        }

        @Override
        public long getItemId(int position) {
            return position;
        }

        @Override
        public View getView(final int position, View convertView, ViewGroup parent) {

            ViewHolder holder = null;

            if (convertView == null) {

                convertView = LayoutInflater.from(mContext).inflate(R.layout.course_alarmclock_tips_list_item, parent, false);
                holder = new ViewHolder();

                holder.tv_className = (TextView) convertView.findViewById(R.id.coursealarmclocktipslistitemTextView1);
                holder.tv_classTime = (TextView) convertView.findViewById(R.id.coursealarmclocktipslistitemTextView2);

                holder.sw_Clock = (Switch)convertView.findViewById(R.id.coursealarmclocktipslistitemSwitch1);

                convertView.setTag(holder);
            } else {
                holder = (ViewHolder) convertView.getTag();
            }

            String CourseName =mData.get(position).getName();
            String jc = LitepalCourseUtil.getJc(mData.get(position).getTime());
            holder.tv_className.setText(CourseName);
            holder.tv_classTime.setText(jc);

            System.out.println("list_getView()" + position);

            //优化Switch控件
            if (Optimize_getView == 0) {
                list_switch.add(holder.sw_Clock);
            }
            if (Optimize_getView == int_list_switch[Optimize_getView_Assist]) {
                list_switch.add(holder.sw_Clock);
                Log.d("添加switch", "" + Optimize_getView);
                if (list_switch.size() < getCount())
                    Optimize_getView_Assist++;
            }



            Log.d("Log_test", "___" + Optimize_getView);

            Optimize_getView++;
            
            holder.sw_Clock.setChecked(Switch_isSelected.get(position));
           // holder.sw_Clock.setChecked(Switch_isSelected.get(position)==null?false:true);
            
            
            

            return convertView;
        }

        @Override
        public void onClick(View p1) {
        }

        private class ViewHolder {
            TextView  tv_className;
            TextView  tv_classTime;
            Switch sw_Clock;
        }
    }
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mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                @Override
                public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {
                    Switch aSwitch=item_Adapter.getaSwitch(position);
                    if (aSwitch.isChecked()) {
                        aSwitch.setChecked(false);
                        //进行业务处理
                    } else {
                        aSwitch.setChecked(true);
                        //进行业务处理
                    }          
                    Toast.makeText(getContext(), aSwitch.isChecked() + "  第" + position, Toast.LENGTH_SHORT).show();
                }
            });
    }

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Origin juejin.im/post/7031557581986332709