无法理解的NullPointerException与自定义适配器 [英] Cannot understand NullPointerException with custom adapter
问题描述
我想创建一个列表视图,因为TextView中,可以显示HTML内容,一个的WebView等基本TextViews.I试图扩大SimpleAdapter但我打的问题,我会很高兴,如果有人能指出错误我所做的一切。
在onCreate方法
的ArrayList< HashMap的<字符串,字符串>> mylist中= resultfromXmlparser();
ADAP =新MyAdapter(TourLandingPage.this,mylist中,R.layout.row,
新的String [] {姓名,说明,持续时间,价格,imgUrl的},新的INT []
{R.id.productname,R.id.des,R.id.duration,R.id.pricefrom,R.id.photo});
setListAdapter(ADAP);
我的自定义适配器看起来是这样的
私有类MyAdapter扩展SimpleAdapter {
ArrayList的< HashMap的<字符串,字符串>>元素;
上下文CTX;
公共MyAdapter(上下文的背景下,ArrayList的< HashMap的<字符串,字符串>> mylist中,INT textViewResourceId,字符串[]名,INT [] resouceid){
超(背景下,mylist中,textViewResourceId,名称,resouceid);
this.elements = mylist中;
this.ctx =背景;
}
@覆盖
公众诠释getCount将(){
返回elements.size();
}
@覆盖
公共对象的getItem(INT位置){
返回elements.get(位置);
}
@覆盖
众长getItemId(INT位置){
返回的位置;
}
@覆盖
公共查看getView(INT位置,查看convertView,ViewGroup中父){
RelativeLayout的RowLayout的;
如果(convertView == NULL){
RowLayout的=(RelativeLayout的)
LayoutInflater.from(CTX).inflate(R.layout.rowfor_tourlist,父母,假);
} 其他 {
RowLayout的=(RelativeLayout的)convertView;
}
TextView的时间=(TextView中)rowLayout.findViewById(R.id.introduction);
TextView的杜=(TextView中)rowLayout.findViewById(R.id.duration);
TextView的PF =(TextView中)rowLayout.findViewById(R.id.pricefrom);
TextView的PN =(TextView中)rowLayout.findViewById(R.id.productname);
的WebView WV =(web视图)rowLayout.findViewById(R.id.photo);
in.setText(Html.fromHtml(mylist.get(位置)获得(降序)));
du.setText(mylist.get(位置)获得(持续时间));
pf.setText(mylist.get(位置)获得(价格));
pn.setText(mylist.get(位置)获得(姓名));
wv.getSettings()setJavaScriptEnabled(真)。
wv.loadUrl(mylist.get(位置)获得(imgUrl的));
返回convertView;
}
}//类
和我的row.xml文件看起来像
RelativeLayout的
的xmlns:机器人=http://schemas.android.com/apk/res/android
机器人:layout_width =FILL_PARENT
机器人:layout_height =FILL_PARENT
的TextView
机器人:ID =@ + ID /产品名称
......
的LinearLayout
机器人:layout_width =WRAP_CONTENT
机器人:layout_height =60dip
机器人:layout_margin =5dip
机器人:layout_below =@用户名/产品名
机器人:方向=横向
机器人:ID =@ + ID / lay1
的WebView
机器人:ID =@ + ID /摄
....
的TextView
机器人:ID =@ + ID /简介
......
的LinearLayout
的TextView
机器人:ID =@ + ID /时间
....
的TextView
机器人:ID =@ + ID / pricefrom
.....
RelativeLayout的
我得到的错误是
04-28 19:46:17.749:ERROR / AndroidRuntime(976):未捕获的处理程序:螺纹主力退出,由于未捕获的异常
04-28 19:46:17.769:ERROR / AndroidRuntime(976):显示java.lang.NullPointerException
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.widget.ListView.setupChild(ListView.java:1693)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.widget.ListView.makeAndAddView(ListView.java:1671)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.widget.ListView.fillDown(ListView.java:637)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.widget.ListView.fillFromTop(ListView.java:694)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.widget.ListView.layoutChildren(ListView.java:1521)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.widget.AbsListView.onLayout(AbsListView.java:1113)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.view.View.layout(View.java:6831)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.widget.LinearLayout.setChildFrame(LinearLayout.java:1119)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.widget.LinearLayout.layoutHorizontal(LinearLayout.java:1108)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.widget.LinearLayout.onLayout(LinearLayout.java:920)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.view.View.layout(View.java:6831)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.widget.LinearLayout.setChildFrame(LinearLayout.java:1119)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.widget.LinearLayout.layoutVertical(LinearLayout.java:998)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.widget.LinearLayout.onLayout(LinearLayout.java:918)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.view.View.layout(View.java:6831)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.widget.FrameLayout.onLayout(FrameLayout.java:333)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.view.View.layout(View.java:6831)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.widget.LinearLayout.setChildFrame(LinearLayout.java:1119)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.widget.LinearLayout.layoutVertical(LinearLayout.java:998)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.widget.LinearLayout.onLayout(LinearLayout.java:918)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.view.View.layout(View.java:6831)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.widget.FrameLayout.onLayout(FrameLayout.java:333)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.view.View.layout(View.java:6831)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.view.ViewRoot.performTraversals(ViewRoot.java:996)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.view.ViewRoot.handleMessage(ViewRoot.java:1633)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.os.Handler.dispatchMessage(Handler.java:99)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.os.Looper.loop(Looper.java:123)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在android.app.ActivityThread.main(ActivityThread.java:4338)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在java.lang.reflect.Method.invokeNative(本机方法)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在java.lang.reflect.Method.invoke(Method.java:521)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run(ZygoteInit.java:860)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
04-28 19:46:17.769:ERROR / AndroidRuntime(976):在dalvik.system.NativeStart.main(本机方法)
04-28 19:46:17.789:信息/工艺(52):发送信号。 PID:976 SIG:3
04-28 19:46:17.799:信息/ dalvikvm(976):主题ID = 7:反应信号3
04-28 19:46:17.829:信息/ dalvikvm(976):写堆栈跟踪/data/anr/traces.txt
不知道这是原因,但最后一个参数SimpleAdapter构造都应该TextViews。
<一个href="http://developer.android.com/reference/android/widget/SimpleAdapter.html#SimpleAdapter%28android.content.Context,%20java.util.List%3C?%20extends%20java.util.Map%3Cjava.lang.String,%20?%3E%3E,%20int,%20java.lang.String%5b%5d,%20int%5b%5d%29"相对=nofollow> SimpleAdapter
I am trying to create a list view which as TextView that can display html content , an WebView and other basic TextViews.I tried to extend SimpleAdapter but i struck with the problem ,I will be glad if someone can point out the mistake i am doing.
In onCreate method
ArrayList<HashMap<String, String>> mylist= resultfromXmlparser();
adap = new MyAdapter(TourLandingPage.this, mylist, R.layout.row,
new String[] {"Name", "desc","Duration","Price","imgurl"}, new int[]
{R.id.productname,R.id.des,R.id.duration,R.id.pricefrom,R.id.photo});
setListAdapter(adap);
My custom Adapter looks like this
private class MyAdapter extends SimpleAdapter {
ArrayList<HashMap<String,String>> elements;
Context ctx;
public MyAdapter(Context context, ArrayList<HashMap<String,String>> mylist,int textViewResourceId,String[] names,int[] resouceid) {
super(context, mylist,textViewResourceId, names,resouceid);
this.elements=mylist;
this.ctx=context;
}
@Override
public int getCount() {
return elements.size();
}
@Override
public Object getItem(int position) {
return elements.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
RelativeLayout rowLayout;
if (convertView == null) {
rowLayout = (RelativeLayout)
LayoutInflater.from(ctx).inflate(R.layout.rowfor_tourlist, parent, false);
} else {
rowLayout = (RelativeLayout) convertView;
}
TextView in = (TextView)rowLayout.findViewById(R.id.introduction);
TextView du = (TextView)rowLayout.findViewById(R.id.duration);
TextView pf = (TextView)rowLayout.findViewById(R.id.pricefrom);
TextView pn = (TextView)rowLayout.findViewById(R.id.productname);
WebView wv=(WebView)rowLayout.findViewById(R.id.photo);
in.setText(Html.fromHtml(mylist.get(position).get("desc")));
du.setText(mylist.get(position).get("Duration"));
pf.setText(mylist.get(position).get("Price"));
pn.setText(mylist.get(position).get("Name"));
wv.getSettings().setJavaScriptEnabled(true);
wv.loadUrl(mylist.get(position).get("imgurl"));
return convertView;
}
}//class
and my row.xml file looks like
RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
TextView
android:id="@+id/productname"
......
LinearLayout
android:layout_width="wrap_content"
android:layout_height="60dip"
android:layout_margin="5dip"
android:layout_below="@id/productname"
android:orientation="horizontal"
android:id="@+id/lay1"
WebView
android:id="@+id/photo"
....
TextView
android:id="@+id/introduction"
......
LinearLayout
TextView
android:id="@+id/duration"
....
TextView
android:id="@+id/pricefrom"
.....
RelativeLayout
The error i was getting was
04-28 19:46:17.749: ERROR/AndroidRuntime(976): Uncaught handler: thread main exiting due to uncaught exception
04-28 19:46:17.769: ERROR/AndroidRuntime(976): java.lang.NullPointerException
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.widget.ListView.setupChild(ListView.java:1693)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.widget.ListView.makeAndAddView(ListView.java:1671)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.widget.ListView.fillDown(ListView.java:637)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.widget.ListView.fillFromTop(ListView.java:694)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.widget.ListView.layoutChildren(ListView.java:1521)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.widget.AbsListView.onLayout(AbsListView.java:1113)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.view.View.layout(View.java:6831)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1119)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.widget.LinearLayout.layoutHorizontal(LinearLayout.java:1108)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.widget.LinearLayout.onLayout(LinearLayout.java:920)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.view.View.layout(View.java:6831)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1119)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.widget.LinearLayout.layoutVertical(LinearLayout.java:998)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.widget.LinearLayout.onLayout(LinearLayout.java:918)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.view.View.layout(View.java:6831)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.widget.FrameLayout.onLayout(FrameLayout.java:333)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.view.View.layout(View.java:6831)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1119)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.widget.LinearLayout.layoutVertical(LinearLayout.java:998)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.widget.LinearLayout.onLayout(LinearLayout.java:918)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.view.View.layout(View.java:6831)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.widget.FrameLayout.onLayout(FrameLayout.java:333)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.view.View.layout(View.java:6831)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.view.ViewRoot.performTraversals(ViewRoot.java:996)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.view.ViewRoot.handleMessage(ViewRoot.java:1633)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.os.Handler.dispatchMessage(Handler.java:99)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.os.Looper.loop(Looper.java:123)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at android.app.ActivityThread.main(ActivityThread.java:4338)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at java.lang.reflect.Method.invokeNative(Native Method)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at java.lang.reflect.Method.invoke(Method.java:521)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
04-28 19:46:17.769: ERROR/AndroidRuntime(976): at dalvik.system.NativeStart.main(Native Method)
04-28 19:46:17.789: INFO/Process(52): Sending signal. PID: 976 SIG: 3
04-28 19:46:17.799: INFO/dalvikvm(976): threadid=7: reacting to signal 3
04-28 19:46:17.829: INFO/dalvikvm(976): Wrote stack trace to '/data/anr/traces.txt'
Not sure if this is the cause but the last parameter to the SimpleAdapter constructor should all be TextViews.
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