Android 从ListView获取视图

我必须在ListView中找到ImageView的坐标，但我做不到。我已尝试使用getItemAtPosition（），但应用程序崩溃。每个ImageView都有一个不同的标记，并且在我的ListView的每一行中

我的职能：

ListView listStudents = (ListView) findViewById(R.id.listStudents);
View view = (View) listStudents.getItemAtPosition(0);

这是我的ListViewAdapter：

private ArrayList<HashMap<String,String>> list = new ArrayList<HashMap<String,String>>();


public ListViewAdapter(Context context, ArrayList<HashMap<String,String>> items) {
     mContext = context;
     this.list = items;
}

public int getCount() {
     return list.size();
}

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

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

@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = new ViewHolder();

if (convertView == null) {
    LayoutInflater inflater = (LayoutInflater)mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    convertView = inflater.inflate(R.layout.row_layout, null);

    /*
     * Button 1
     */
    holder.imageStudent   = (ImageView)convertView.findViewById(R.id.firstStudentImage);
    holder.imageStudent.setAlpha(50);
    holder.imageStudent.setOnClickListener(this);
    holder.imageStudent.setTag(this.numElements);
    holder.nameStudent   = (TextView)convertView.findViewById(R.id.firstStudentName);

    /*
     * Button 2
     */
    holder.imageStudent2   = (ImageView)convertView.findViewById(R.id.secondStudentImage);
    holder.imageStudent2.setAlpha(50);
    holder.imageStudent2.setOnClickListener(this);
    holder.imageStudent2.setTag(this.numElements+1);
    holder.nameStudent2   = (TextView)convertView.findViewById(R.id.secondStudentName);


    /*
     * Button 3
     */
    holder.imageStudent3   = (ImageView)convertView.findViewById(R.id.thirdStudentImage);
    holder.imageStudent3.setAlpha(50);
    holder.nameStudent3 = (TextView)convertView.findViewById(R.id.thirdStudentName);
    holder.imageStudent3.setTag(this.numElements+2);
    holder.imageStudent3.setOnClickListener(this);


    holder.imageStudent4   = (ImageView)convertView.findViewById(R.id.fourthStudentImage);
    holder.imageStudent4.setAlpha(50);
    holder.nameStudent4 = (TextView)convertView.findViewById(R.id.fourthStudentName);
    long value = 2723250804L;
    holder.imageStudent4.setTag(value);
    holder.imageStudent4.setOnClickListener(this);

    /*
     * Button 5
     */
    holder.imageStudent5   = (ImageView)convertView.findViewById(R.id.fivethStudentImage);
    holder.imageStudent5.setAlpha(50);
    holder.nameStudent5   = (TextView)convertView.findViewById(R.id.fivethStudentName);
    holder.imageStudent5.setTag(this.numElements+4);
    holder.imageStudent5.setOnClickListener(this);

    /*
     * Button 6
     */
    holder.imageStudent6   = (ImageView)convertView.findViewById(R.id.sixthStudentImage);
    holder.imageStudent6.setAlpha(50);
    holder.nameStudent6   = (TextView)convertView.findViewById(R.id.sixthStudentName);
    holder.imageStudent6.setTag(this.numElements+5);
    holder.imageStudent6.setOnClickListener(this);


    convertView.setTag(holder);

    int  idImage = this.mContext.getResources().getIdentifier(this.list.get(position).get("studentImage"),"drawable", this.mContext.getPackageName());
    Drawable myDrawable = this.mContext.getResources().getDrawable(idImage);
    holder.imageStudent.setImageDrawable(myDrawable);
    holder.nameStudent.setText(this.list.get(position).get("studentName"));


    idImage = this.mContext.getResources().getIdentifier(this.list.get(position).get("studentImage2"),"drawable", this.mContext.getPackageName());
    myDrawable = this.mContext.getResources().getDrawable(idImage);
    holder.imageStudent2.setImageDrawable(myDrawable);
    holder.nameStudent2.setText(this.list.get(position).get("studentName2"));

    idImage = this.mContext.getResources().getIdentifier(this.list.get(position).get("studentImage3"),"drawable", this.mContext.getPackageName());
    myDrawable = this.mContext.getResources().getDrawable(idImage);
    holder.imageStudent3.setImageDrawable(myDrawable);
    holder.nameStudent3.setText(this.list.get(position).get("studentName3"));

    idImage = this.mContext.getResources().getIdentifier(this.list.get(position).get("studentImage4"),"drawable", this.mContext.getPackageName());
    myDrawable = this.mContext.getResources().getDrawable(idImage);
    holder.imageStudent4.setImageDrawable(myDrawable);
    holder.nameStudent4.setText(this.list.get(position).get("studentName4"));

    idImage = this.mContext.getResources().getIdentifier(this.list.get(position).get("studentImage5"),"drawable", this.mContext.getPackageName());
    myDrawable = this.mContext.getResources().getDrawable(idImage);
    holder.imageStudent5.setImageDrawable(myDrawable);
    holder.nameStudent5.setText(this.list.get(position).get("studentName5"));

    idImage = this.mContext.getResources().getIdentifier(this.list.get(position).get("studentImage6"),"drawable", this.mContext.getPackageName());
    myDrawable = this.mContext.getResources().getDrawable(idImage);
    holder.imageStudent6.setImageDrawable(myDrawable);
    holder.nameStudent6.setText(this.list.get(position).get("studentName3"));
}
else
{
    holder = (ViewHolder)convertView.getTag();
}


return convertView;
}

@SuppressWarnings("deprecation")
@Override
public void onClick(View v) {
    EventActivity.currentButton = (Integer) v.getTag();
Activity activity = (Activity) mContext;
activity.showDialog(1);
EventActivity.currentView = (View) v.getParent();
}

---

这是一个

ClassCastException

EventActivity.currentButton = (Integer) v.getTag(); 

我认为这条线上有错误

long值=2723250804L

这是long值，您将其设置为标记，然后尝试将此long值转换为整数。我认为这是不可能的

实际上v.getTag（）返回对象。您正在尝试将对象转换为整数。我确信
v.getTag（）返回整数。那么只有它有效（）

EventActivity.currentButton的数据类型是什么？
？
签出。我认为它回答了您的问题，即如何通过使用
setTag
和
getTag
方法在特定位置查找某个对象来获取视图

错误是一个
ClassCastException
。在代码末尾将标记id转换为
视图持有者
的位置，或者将视图标记转换为
整数
。请看上面的示例，并以这种方式设置代码以避免此错误
 你能把代码贴在你试图获取物品和崩溃日志的地方吗？你的崩溃说明了什么？logcat输出可能与调用
listStudents.getItemAtPosition（0）的位置重复
，在
onCreate（）
中，我调用getItemAtPosition（0）；在onCreate中的函数内部，但在SetAdapter之后。
    04-05 15:57:46.238: E/AndroidRuntime(22906): FATAL EXCEPTION: main
04-05 15:57:46.238: E/AndroidRuntime(22906): java.lang.ClassCastException: java.lang.Integer cannot be cast to com.nsts.eventmarker.ListViewAdapter$ViewHolder
04-05 15:57:46.238: E/AndroidRuntime(22906):    at com.nsts.eventmarker.ListViewAdapter.getView(ListViewAdapter.java:187)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.widget.AbsListView.obtainView(AbsListView.java:2143)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.widget.ListView.measureHeightOfChildren(ListView.java:1246)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.widget.ListView.onMeasure(ListView.java:1158)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.view.View.measure(View.java:15513)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4827)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1404)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.widget.LinearLayout.measureVertical(LinearLayout.java:695)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.widget.LinearLayout.onMeasure(LinearLayout.java:588)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.view.View.measure(View.java:15513)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4827)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.view.View.measure(View.java:15513)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.widget.LinearLayout.measureVertical(LinearLayout.java:847)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.widget.LinearLayout.onMeasure(LinearLayout.java:588)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.view.View.measure(View.java:15513)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4827)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2176)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.view.View.measure(View.java:15513)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1874)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1089)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1265)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:989)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4351)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.view.Choreographer.doCallbacks(Choreographer.java:562)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.view.Choreographer.doFrame(Choreographer.java:532)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.os.Handler.handleCallback(Handler.java:725)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.os.Handler.dispatchMessage(Handler.java:92)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.os.Looper.loop(Looper.java:137)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at android.app.ActivityThread.main(ActivityThread.java:5039)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at java.lang.reflect.Method.invokeNative(Native Method)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at java.lang.reflect.Method.invoke(Method.java:511)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
04-05 15:57:46.238: E/AndroidRuntime(22906):    at dalvik.system.NativeStart.main(Native Method)

EventActivity.currentButton = (Integer) v.getTag();