我得到这个expcetion：
java.lang.ClassCastException: android.view.ViewGroup$LayoutParams cannot be cast to android.widget.AbsListView$LayoutParams at android.widget.ListView.setupChild(ListView.java:1806) at android.widget.ListView.makeAndAddView(ListView.java:1775) at android.widget.ListView.fillDown(ListView.java:672) at android.widget.ListView.fillFromTop(ListView.java:732) at android.widget.ListView.layoutChildren(ListView.java:1625) at android.widget.AbsListView.onLayout(AbsListView.java:1863) at android.view.View.layout(View.java:11278) at android.view.ViewGroup.layout(ViewGroup.java:4224) at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1628) at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1486) at android.widget.LinearLayout.onLayout(LinearLayout.java:1399) at android.view.View.layout(View.java:11278) at android.view.ViewGroup.layout(ViewGroup.java:4224) at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1628) at android.widget.LinearLayout.layoutHorizontal(LinearLayout.java:1617) at android.widget.LinearLayout.onLayout(LinearLayout.java:1401) at android.view.View.layout(View.java:11278) at android.view.ViewGroup.layout(ViewGroup.java:4224) at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1628) at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1486) at android.widget.LinearLayout.onLayout(LinearLayout.java:1399) at android.view.View.layout(View.java:11278) at android.view.ViewGroup.layout(ViewGroup.java:4224) at android.widget.FrameLayout.onLayout(FrameLayout.java:431) at android.view.View.layout(View.java:11278) at android.view.ViewGroup.layout(ViewGroup.java:4224) at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1628) at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1486) at android.widget.LinearLayout.onLayout(LinearLayout.java:1399) at android.view.View.layout(View.java:11278) at android.view.ViewGroup.layout(ViewGroup.java:4224) at android.widget.FrameLayout.onLayout(FrameLayout.java:431) at android.view.View.layout(View.java:11278) at android.view.ViewGroup.layout(ViewGroup.java:4224) at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1504) at android.view.ViewRootImpl.handleMessage(ViewRootImpl.java:2458) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:137) at android.app.ActivityThread.main(ActivityThread.java:4424) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:511) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) at dalvik.system.NativeStart.main(Native Method)
但问题是我找不到问题的根源.究竟在哪里呢？
为什么小部件,我没有任何小部件！
码：
不确定在这里：
public class MyListPreference extends ListPreference {
public MyListPreference(Context context) {
super(context);
}
public MyListPreference(Context context,AttributeSet attrs) {
super(context,attrs);
}
@Override
protected View onCreateDialogView() {
TextView dialogTitle = (TextView)super.onCreateDialogView();
if (dialogTitle != null) {
// Dialog
dialogTitle.setBackgroundColor(getContext().getResources().getColor(R.color.category_background));
dialogTitle.setPadding(10,4,4);
// Text
dialogTitle.setTextSize(14);
dialogTitle.setTypeface(null,Typeface.BOLD);
dialogTitle.setTextColor(getContext().getResources().getColor(R.color.actionbar_background));
dialogTitle.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.MATCH_PARENT));
}
return dialogTitle;
}
}
解决方法
dialogTitle.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.MATCH_PARENT));
在这里,您正在使用更通用的ViewGroup.LayoutParams替换正确类型AbsListView.LayoutParams的现有布局参数.布局参数类型是视图的父容器的类型.
如果您需要修改现有的布局参数,请使用getLayoutParams()访问它们,修改它,并调用requestLayout()来通知布局已更改.
例.代替
fooView.setLayoutParams(new LayoutParams(123,456));
做
LayoutParams lp = fooView.getLayoutParams(); lp.width = 123; lp.height = 456; fooView.requestLayout();
