ListView控件过滤的错误 [英] listView filter mistake

问题描述

 公共类testListFilter扩展ListActivity {
/ **当第一次创建活动调用。 * /
ArrayList的＆LT; GlycaemicIndexItem＆GT;项目;
@覆盖
公共无效的onCreate（捆绑savedInstanceState）{
    super.onCreate（savedInstanceState）;
    GlycaemicIndexItem GL =新GlycaemicIndexItem（）;
    gl.setName（王）;
    gl.setimagepath（DFD）;
    GlycaemicIndexItem G2 =新GlycaemicIndexItem（）;
    g2.setName（「李先生」）;
    g2.setimagepath（DFD）;
    GlycaemicIndexItem G3 =新GlycaemicIndexItem（）;
    g3.setName（嘀）;
    g3.setimagepath（DFD）;
    GlycaemicIndexItem G4 =新GlycaemicIndexItem（）;
    g4.setName（di34）;
    g4.setimagepath（DFD）;
    GlycaemicIndexItem G5 =新GlycaemicIndexItem（）;
    g5.setName（ai34）;
    g5.setimagepath（DFD）;
    GlycaemicIndexItem G6 =新GlycaemicIndexItem（）;
    g6.setName（香鱼）;
    g6.setimagepath（DFD）;    items.add（GL）;
    items.add（G2）;
    items.add（G3）;
    items.add（G4）;
    items.add（G5）;
    items.add（G6）;
    GlycaemicIndexItemAdapter GI =新GlycaemicIndexItemAdapter（这一点，1项）;
    getListView（）setAdapter（GI）。
   // setListAdapter（GI）;
}
}
   公共类GlycaemicIndexItem {
  公共字符串名称;
  公共字符串的ImagePath;
  公共字符串的getName（）{
    返回名称;
    }
      公共无效setname可以（字符串名称）{
   this.name =名称;
        }       公共字符串getimagepath（）{
    返回的ImagePath;
  }
    公共无效setimagepath（字符串的ImagePath）{
   this.imagepath =的ImagePath;
    }
 }
 

和GlycaemicIndexItemAdapter我从<一个名为href=\"http://stackoverflow.com/questions/2519317/how-tto-write-a-custom-filter-for-listview-with-arrayadapter\">How写一个自定义过滤器与ArrayAdapter ListView的，但是当我运行这个程序，它显示：

 
十月3日至23日：52：03.903：ERROR / AndroidRuntime（971）：了java.lang.RuntimeException：无法启动活动ComponentInfo {com.test.testListFilter / com.test.testListFilter.testListFilter}：显示java.lang.NullPointerException
十月3日至23日：52：03.903：ERROR / AndroidRuntime（971）：在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2663）
十月3日至23日：52：03.903：ERROR / AndroidRuntime（971）：在android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:2679）
十月3日至23日：52：03.903：ERROR / AndroidRuntime（971）：在android.app.ActivityThread.access $ 2300（ActivityThread.java:125）
十月3日至23日：52：03.903：ERROR / AndroidRuntime（971）：在com.test.testListFilter.testListFilter.onCreate（testListFilter.java:33）
 

编辑：<一href=\"http://stackoverflow.com/questions/2519317/how-to-write-a-custom-filter-for-listview-with-arrayadapter/5381365#5381365\">How写与ArrayAdapter的ListView自定义过滤器是很好的，如果需要你可以看到这个链接

解决方案

 项目=新的ArrayList＆LT; GlycaemicIndexItem＆GT;（）;
 

在的onCreate的第一行添加此。

感谢。

public class testListFilter extends ListActivity {
/** Called when the activity is first created. */
ArrayList<GlycaemicIndexItem> items;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    GlycaemicIndexItem gl= new GlycaemicIndexItem();
    gl.setName("wang");
    gl.setimagepath("dfd");
    GlycaemicIndexItem g2= new GlycaemicIndexItem();
    g2.setName("li");
    g2.setimagepath("dfd");
    GlycaemicIndexItem g3= new GlycaemicIndexItem();
    g3.setName("di");
    g3.setimagepath("dfd");
    GlycaemicIndexItem g4= new GlycaemicIndexItem();
    g4.setName("di34");
    g4.setimagepath("dfd");
    GlycaemicIndexItem g5= new GlycaemicIndexItem();
    g5.setName("ai34");
    g5.setimagepath("dfd");
    GlycaemicIndexItem g6= new GlycaemicIndexItem();
    g6.setName("ayu");
    g6.setimagepath("dfd");

    items.add(gl);
    items.add(g2);
    items.add(g3);
    items.add(g4);
    items.add(g5);
    items.add(g6);
    GlycaemicIndexItemAdapter Gi=new GlycaemicIndexItemAdapter(this,1,items);
    getListView().setAdapter(Gi);
   // setListAdapter(Gi);
}
}


   public class GlycaemicIndexItem {
  public String name;
  public String imagepath;
  public String  getName(){
    return name;
    }
      public  void setName( String  name){
   this.name=name;
        }

       public String  getimagepath(){
    return imagepath;
  }
    public  void setimagepath(String  imagepath){
   this.imagepath=imagepath;
    }
 }

and GlycaemicIndexItemAdapter i called from How to write a custom filter for ListView with ArrayAdapter, but when i run this app, it is show:

03-23 10:52:03.903: ERROR/AndroidRuntime(971): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.test.testListFilter/com.test.testListFilter.testListFilter}: java.lang.NullPointerException


03-23 10:52:03.903: ERROR/AndroidRuntime(971):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)


03-23 10:52:03.903: ERROR/AndroidRuntime(971):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)


03-23 10:52:03.903: ERROR/AndroidRuntime(971):     at android.app.ActivityThread.access$2300(ActivityThread.java:125)


03-23 10:52:03.903: ERROR/AndroidRuntime(971):     at com.test.testListFilter.testListFilter.onCreate(testListFilter.java:33)

edit: How to write a custom filter for ListView with ArrayAdapter is very well, if you need you can see this link

解决方案

items=new ArrayList<GlycaemicIndexItem>();

add this in first line of onCreate.

Thanks.

这篇关于ListView控件过滤的错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！