我有一个包含 3 种不同类型行的 listView。我在网上收到 ClassCastException
holder = (RowViewHolder) row.getTag();
我注意到 row.getTag() 返回 HeaderViewHolder。为什么会这样,我该如何解决?
这是我的代码:
header_row.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:id="@+id/categoryNameTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:gravity="center"
android:textAppearance="?android:attr/textAppearanceMedium" />
</RelativeLayout>
queue_row.xml
<?xml version="1.0" encoding="utf-8"?>
<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:layout_marginRight="10dp"
tools:ignore="HardcodedText,ContentDescription" >
<ImageView
android:id="@+id/qItemImageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/ic_launcher" />
<TextView
android:id="@+id/qItemNameTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="5dp"
android:layout_toRightOf="@id/qItemImageView"
android:gravity="center"
android:text="Medium Text"
android:textAppearance="?android:attr/textAppearanceMedium" />
<ProgressBar
android:id="@+id/qProgressBar"
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/qItemNameTextView"
android:layout_alignParentRight="true"
android:layout_below="@+id/qItemNameTextView"
android:max="100"
android:progress="50" />
<TextView
android:id="@+id/qLevelTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignRight="@id/qItemImageView"
android:layout_alignTop="@id/qItemImageView"
android:text="7"
android:textAppearance="?android:attr/textAppearanceMedium"
android:textStyle="bold" />
<TextView
android:id="@+id/qTimeTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@id/qProgressBar"
android:layout_alignLeft="@id/qProgressBar"
android:layout_alignRight="@id/qProgressBar"
android:layout_alignTop="@id/qProgressBar"
android:layout_centerHorizontal="true"
android:gravity="center"
android:text="01:01:01"
android:textAppearance="?android:attr/textAppearanceMedium"
android:textColor="@android:color/black" />
</RelativeLayout>
行.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/RelativeLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:ignore="HardcodedText,ContentDescription" >
<ImageView
android:id="@+id/itemImageView"
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:src="@drawable/ic_launcher" />
<TextView
android:id="@+id/nameTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:layout_toRightOf="@+id/itemImageView"
android:gravity="center"
android:text="Large Text"
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="@+id/levelTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignRight="@id/itemImageView"
android:layout_alignTop="@id/itemImageView"
android:text="7"
android:textAppearance="?android:attr/textAppearanceMedium"
android:textStyle="bold" />
<LinearLayout
android:id="@+id/priceLayout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/nameTextView"
android:layout_alignParentRight="true"
android:layout_below="@+id/nameTextView"
android:baselineAligned="false"
android:gravity="center"
android:orientation="horizontal" >
<TextView
android:id="@+id/woodTextView"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_weight="1"
android:drawableLeft="@drawable/wood"
android:gravity="center"
android:text="111"
android:textAppearance="?android:attr/textAppearanceSmall" />
<TextView
android:id="@+id/ironTextView"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_weight="1"
android:drawableLeft="@drawable/iron"
android:gravity="center"
android:text="111"
android:textAppearance="?android:attr/textAppearanceSmall" />
<TextView
android:id="@+id/stoneTextView"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_weight="1"
android:drawableLeft="@drawable/stone"
android:gravity="center"
android:text="111"
android:textAppearance="?android:attr/textAppearanceSmall" />
<TextView
android:id="@+id/goldTextView"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_weight="1"
android:drawableLeft="@drawable/gold"
android:gravity="center"
android:text="111"
android:textAppearance="?android:attr/textAppearanceSmall" />
</LinearLayout>
<Button
android:id="@+id/actionButton"
android:layout_width="90dp"
android:layout_height="37dp"
android:layout_alignParentRight="true"
android:layout_below="@id/priceLayout"
android:text="Buduj" />
<TextView
android:id="@+id/timeTextView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignBaseline="@id/actionButton"
android:layout_toLeftOf="@id/actionButton"
android:layout_toRightOf="@id/itemImageView"
android:gravity="center"
android:text="Medium Text"
android:textAppearance="?android:attr/textAppearanceSmall" />
</RelativeLayout>
和java文件的重要部分:
BuildingsAdapter.java
class BuildingsAdapter extends ArrayAdapter<BaseRow> {
@Override
public int getItemViewType(int position) {
return getItem(position).getType();
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
int type = getItemViewType(position);
View row = convertView;
switch (type) {
case BaseRow.QUEUE_ROW: {
QueueRowViewHolder holder = new QueueRowViewHolder();
if (row == null) {
LayoutInflater inflater = (LayoutInflater) getContext()
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
row = inflater.inflate(R.layout.queue_row, parent, false);
holder.qItemImageView_ = (ImageView) row
.findViewById(R.id.qItemImageView);
(..........)
row.setTag(holder);
} else {
holder = (QueueRowViewHolder) row.getTag();
}
final QueueRow queueRow = (QueueRow) getItem(position);
if (queueRow != null) {
if (holder.qItemImageView_ != null) {
(..........)
holder.qItemImageView_.setImageBitmap(bm);
}
if (holder.qItemNameTextView_ != null) {
holder.qItemNameTextView_.setText(queueRow.getName());
}
if (holder.qProgressBar_ != null) {
holder.qProgressBar_.setProgress(queueRow.getProgress());
}
if (holder.qLevelTextView_ != null) {
holder.qLevelTextView_.setText(queueRow.getLevel());
}
if (holder.qTimeTextView_ != null) {
holder.qTimeTextView_.setText(queueRow.getTime());
}
}
return row;
}
case BaseRow.ROW: {
RowViewHolder holder = new RowViewHolder();
if (row == null) {
LayoutInflater inflater = (LayoutInflater) getContext()
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
row = inflater.inflate(R.layout.row, parent, false);
(..........)
row.setTag(holder);
} else {
holder = (RowViewHolder) row.getTag();
}
final Row element = (Row) getItem(position);
row.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(mainActivity_, element.getDescription(),
Toast.LENGTH_LONG).show();
}
});
if (element != null) {
if (holder.itemImageView_ != null) {
(..........)
holder.itemImageView_.setImageBitmap(bm);
}
if (holder.nameTextView_ != null)
holder.nameTextView_.setText(element.getName());
if (holder.levelTextView_ != null)
holder.levelTextView_.setText(String.valueOf(element
.getLevel()));
if (holder.woodTextView_ != null)
holder.woodTextView_.setText(String.valueOf(element
.getWoodPrice()));
if (holder.ironTextView_ != null)
holder.ironTextView_.setText(String.valueOf(element
.getIronPrice()));
if (holder.stoneTextView_ != null)
holder.stoneTextView_.setText(String.valueOf(element
.getStonePrice()));
if (holder.goldTextView_ != null)
holder.goldTextView_.setText(String.valueOf(element
.getGoldPrice()));
if (holder.timeTextView_ != null)
holder.timeTextView_.setText(element.getTime());
if (holder.actionButton_ != null && element.getAction() != null) {
holder.actionButton_
.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
BuildingsAdapter.this.mainActivity_.webView_
.loadUrl("javascript:"
+ element.getAction());
}
});
} else {
holder.actionButton_.setEnabled(false);
}
}
return row;
}
case BaseRow.HEADER_ROW: {
HeaderViewHolder holder = new HeaderViewHolder();
if (row == null) {
LayoutInflater inflater = (LayoutInflater) getContext()
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
row = inflater.inflate(R.layout.header_row, parent, false);
HeaderRow headerRow = (HeaderRow) getItem(position);
holder.nameTextView_ = (TextView) row
.findViewById(R.id.categoryNameTextView);
holder.nameTextView_.setText(headerRow.getName());
row.setTag(holder);
} else {
holder = (HeaderViewHolder) row.getTag();
}
return row;
}
}
return null;
}
static class QueueRowViewHolder {
ImageView qItemImageView_;
TextView qItemNameTextView_;
ProgressBar qProgressBar_;
TextView qLevelTextView_;
TextView qTimeTextView_;
int position_;
}
static class RowViewHolder {
ImageView itemImageView_;
TextView nameTextView_;
TextView levelTextView_;
TextView woodTextView_;
TextView ironTextView_;
TextView stoneTextView_;
TextView goldTextView_;
Button actionButton_;
TextView timeTextView_;
}
static class HeaderViewHolder {
TextView nameTextView_;
}
}
你有什么想法有什么问题吗?这里确切的日志:
06-18 22:40:35.899: E/AndroidRuntime(2015): FATAL EXCEPTION: main
06-18 22:40:35.899: E/AndroidRuntime(2015): java.lang.ClassCastException: kks.imperioid.BuildingsAdapter$HeaderViewHolder
06-18 22:40:35.899: E/AndroidRuntime(2015): at kks.imperioid.BuildingsAdapter.getView(BuildingsAdapter.java:146)
06-18 22:40:35.899: E/AndroidRuntime(2015): at android.widget.AbsListView.obtainView(AbsListView.java:1589)
06-18 22:40:35.899: E/AndroidRuntime(2015): at android.widget.ListView.makeAndAddView(ListView.java:1795)
06-18 22:40:35.899: E/AndroidRuntime(2015): at android.widget.ListView.fillDown(ListView.java:718)
06-18 22:40:35.899: E/AndroidRuntime(2015): at android.widget.ListView.fillGap(ListView.java:689)
06-18 22:40:35.899: E/AndroidRuntime(2015): at android.widget.AbsListView.trackMotionScroll(AbsListView.java:4173)
06-18 22:40:35.899: E/AndroidRuntime(2015): at android.widget.AbsListView.onTouchEvent(AbsListView.java:2610)
06-18 22:40:35.899: E/AndroidRuntime(2015): at android.widget.ListView.onTouchEvent(ListView.java:3682)
06-18 22:40:35.899: E/AndroidRuntime(2015): at android.view.View.dispatchTouchEvent(View.java:3885)
06-18 22:40:35.899: E/AndroidRuntime(2015): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:903)
06-18 22:40:35.899: E/AndroidRuntime(2015): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:942)
06-18 22:40:35.899: E/AndroidRuntime(2015): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:942)
06-18 22:40:35.899: E/AndroidRuntime(2015): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:942)
06-18 22:40:35.899: E/AndroidRuntime(2015): at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1750)
06-18 22:40:35.899: E/AndroidRuntime(2015): at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1135)
06-18 22:40:35.899: E/AndroidRuntime(2015): at android.app.Activity.dispatchTouchEvent(Activity.java:2096)
06-18 22:40:35.899: E/AndroidRuntime(2015): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1734)
06-18 22:40:35.899: E/AndroidRuntime(2015): at android.view.ViewRoot.deliverPointerEvent(ViewRoot.java:2216)
06-18 22:40:35.899: E/AndroidRuntime(2015): at android.view.ViewRoot.handleMessage(ViewRoot.java:1887)
06-18 22:40:35.899: E/AndroidRuntime(2015): at android.os.Handler.dispatchMessage(Handler.java:99)
06-18 22:40:35.899: E/AndroidRuntime(2015): at android.os.Looper.loop(Looper.java:130)
06-18 22:40:35.899: E/AndroidRuntime(2015): at android.app.ActivityThread.main(ActivityThread.java:3687)
06-18 22:40:35.899: E/AndroidRuntime(2015): at java.lang.reflect.Method.invokeNative(Native Method)
06-18 22:40:35.899: E/AndroidRuntime(2015): at java.lang.reflect.Method.invoke(Method.java:507)
06-18 22:40:35.899: E/AndroidRuntime(2015): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
06-18 22:40:35.899: E/AndroidRuntime(2015): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625)
06-18 22:40:35.899: E/AndroidRuntime(2015): at dalvik.system.NativeStart.main(Native Method)