【问题标题】:How to update the listview when i click the button?单击按钮时如何更新列表视图?
【发布时间】:2013-01-13 22:13:33
【问题描述】:
    public class MainActivity extends Activity {
    ListView list;
    String[] abc={"1","2","3"};
    MyCustomAdapter adapter;
    Button refresh;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);
            list=(ListView) findViewById(R.id.list);
             refresh=(Button) findViewById(R.id.refresh);
             adapter=new MyCustomAdapter(MainActivity.this,abc);
            list.setAdapter(adapter);

        }
         private class MyCustomAdapter extends BaseAdapter {
                private final Context context;
                private ArrayList mData = new ArrayList();
                private LayoutInflater mInflater;
                private String[] hashmap;
                ViewHolder holder = null;
                public MyCustomAdapter(Context context,String[] hashMaps) {
                    super();
                    this.context = context;
                    this.hashmap = hashMaps;
                    mInflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                }
                public int getCount() {

                    return hashmap.length;

                }


                public Object getItem(int position) {
                    return hashmap.length;
                }


                public long getItemId(int position) {

                    return position;
                }

                @Override
                public void notifyDataSetChanged() // Create this function in your adapter class
                {
                    super.notifyDataSetChanged();
                }
                @Override
                public View getView(final int position, View convertView, ViewGroup parent) {
                    System.out.println("getView " + position + " " + convertView);
                   // final ViewHolder holder = null;
                    if (convertView == null) {
                        convertView = mInflater.inflate(R.layout.view1, null);
                        holder = new ViewHolder();
                        holder.textView = (TextView)convertView.findViewById(R.id.text);
                        holder.btn = (Button)convertView.findViewById(R.id.refresh);
                        convertView.setTag(holder);
                    } else {
                        holder = (ViewHolder)convertView.getTag();
                    }
                    holder.textView.setText(hashmap[position]);

                    holder.btn.setOnClickListener(new OnClickListener(){  
                           @Override
                          public void onClick(View v) {
                             RelativeLayout rl = (RelativeLayout)v.getParent();
                            holder.textView = (TextView)rl.getChildAt(position);
                            Log.i("position",String.valueOf(position));
                            holder.textView.setText("10");
                           }
                         });

                    return convertView;

                }

            }

            public static class ViewHolder {
                public TextView textView;
                public Button btn;
            }




    }

View.xml

<RelativeLayout 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:id="@+id/real"
    >
    <TextView 
                android:id="@+id/text"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignParentLeft="true"
                android:text="Text"
                android:layout_marginTop="15dp"
                android:layout_marginLeft="20dp"
                />
    <Button 
                android:id="@+id/refresh"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_toRightOf="@id/text"
                android:text="button"
                 android:layout_marginLeft="20dp"
                />
    </RelativeLayout>

在我的 ListView 中,当我单击按钮时,适配器视图中的值未更改。如何解决此问题?该列表包含每个位置的 3 个值。因此,当我单击单击位置的按钮时,该值将更改而不是旧值。

【问题讨论】:

标签: android button android-listview


【解决方案1】:

修改getView方法代码如下。

@Override
        public View getView(final int position, View convertView,ViewGroup parent) {
            View vi = convertView;
            final TextView textView;
            if (convertView == null)
                inflater = (LayoutInflater)    context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            vi = inflater.inflate(R.layout.vi, null);

            textView = (TextView) vi.findViewById(R.id.text);
            Button btn = (Button) vi.findViewById(R.id.refresh);
            textView.setText(hashmap[position]);
            btn.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View v) {
                    Log.i("position  ", position + "");
                    textView.setText("10");
                }
            });

            return vi;
        }

【讨论】:

    【解决方案2】:

    试试这个:

    holder.btn.setTag(convertView);
    
    holder.btn.setOnClickListener(new OnClickListener(){  
    
                           @Override
                          public void onClick(View v) {
                              View tempView = v.getTag();
                TextView tv = (TextView)tempView.findViewById(R.id.text);
                tv.setText("your string");  
                           }
                         });
    

    【讨论】:

      【解决方案3】:

      叫这个

      setListAdapter(new ArrayAdapter<String>(this, R.layout.list_item, your_new_value));
      

      欲了解更多信息,请尝试link

      【讨论】:

        【解决方案4】:

        对于更新值列表视图,您可以使用adapter.notifyDataSetChanged() 这将刷新您的列表适配器。但是在更改数据源中的值后调用它。

        【讨论】:

          【解决方案5】:

          你应该使用 notifyDataSetChanged() 方法来刷新你的列表视图...

          在适配器上调用 notifyDataSetChanged()

            refresh.setOnClickListener(new OnClickListener() {
                      @Override
                      public void onClick(View p_v) {
                          // TODO Auto-generated method stub
                          adapter.notifyDataSetChanged();
                      }
                  });
          

          【讨论】:

          • 我正在使用 holder.its 在行 list.notifyDataSetChanged() 中不起作用;错误ListView类型的notifyDataSetChanged()方法未定义
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