Question

我的以下代码适用于我的API 21设备但是，它无法在Android Studio中的Nexus 7 API 19仿真器上运行：

@Override
public View getView(int position, View convertView, ViewGroup parent)
{
    LayoutInflater inflater = LayoutInflater.from(getContext());
    View customView = inflater.inflate(R.layout.shopping_list_cell, parent, false);


    customView.setLayoutParams(new RelativeLayout.LayoutParams(cellWidth, cellHeight + 20));
    customView.requestLayout();


    return customView;
}

导致此问题的确切行如下（当我取出这两行时，我在模拟器上没有出现任何错误）：

customView.setLayoutParams(new RelativeLayout.LayoutParams(cellWidth, cellHeight + 20));
customView.requestLayout();

这是我的错误消息：

致命的例外：主要进程：john.smith.johnsmith.testapplication，PID：1649 java.lang.ClassCastException：android.widget.RelativeLayout $ LayoutParams无法强制转换为android.widget.AbsListView $ LayoutParams 在android.widget.ListView.setupChild（ListView.java:1826）在android.widget.ListView.makeAndAddView（ListView.java:1793）在android.widget.ListView.fillDown（ListView.java:691）在android.widget.ListView.fillFromTop（ListView.java:752）在android.widget.ListView.layoutChildren（ListView.java:1630）在android.widget.AbsListView.onLayout（AbsListView.java:2091）在android.view.View.layout（View.java:14817）在android.view.ViewGroup.layout（ViewGroup.java:4631）在android.widget.RelativeLayout.onLayout（RelativeLayout.java:1055）在android.view.View.layout（View.java:14817）在android.view.ViewGroup.layout（ViewGroup.java:4631）在android.widget.FrameLayout.layoutChildren（FrameLayout.java:453）在android.widget.FrameLayout.onLayout（FrameLayout.java:388）在android.view.View.layout（View.java:14817）在android.view.ViewGroup.layout（ViewGroup.java:4631）在android.widget.LinearLayout.setChildFrame（LinearLayout.java:1671）在android.widget.LinearLayout.layoutVertical（LinearLayout.java:1525）在android.widget.LinearLayout.onLayout（LinearLayout.java:1434）在android.view.View.layout（View.java:14817）在android.view.ViewGroup.layout（ViewGroup.java:4631）在android.widget.FrameLayout.layoutChildren（FrameLayout.java:453）在android.widget.FrameLayout.onLayout（FrameLayout.java:388）在android.view.View.layout（View.java:14817）在android.view.ViewGroup.layout（ViewGroup.java:4631）在android.view.ViewRootImpl.performLayout（ViewRootImpl.java:1987）在android.view.ViewRootImpl.performTraversals（ViewRootImpl.java:1744）在android.view.ViewRootImpl.doTraversal（ViewRootImpl.java:1000）在android.view.ViewRootImpl $ TraversalRunnable.run（ViewRootImpl.java:5670）在android.view.Choreographer $ CallbackRecord.run（Choreographer.java:761）在android.view.Choreographer.doCallbacks（Choreographer.java:574）在android.view.Choreographer.doFrame（Choreographer.java:544）在android.view.Choreographer $ FrameDisplayEventReceiver.run（Choreographer.java:747）在android.os.Handler.handleCallback（Handler.java:733）在android.os.Handler.dispatchMessage（Handler.java:95）在android.os.Looper.loop（Looper.java:136）在android.app.ActivityThread.main（ActivityThread.java:5017） at java.lang.reflect.Method.invokeNative（Native Method）在java.lang.reflect.Method.invoke（Method.java:515）在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:779）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:595）在dalvik.system.NativeStart.main（本地方法）

Answer 1

尝试将Relative.LayoutParams更改为AbsListView.LayoutParams：

 @Override
    public View getView(int position, View convertView, ViewGroup parent)
    {
        LayoutInflater inflater = LayoutInflater.from(getContext());
        View customView = inflater.inflate(R.layout.shopping_list_cell, parent, false);


        customView.setLayoutParams(new AbsListView.LayoutParams(cellWidth, cellHeight + 20));
       //remove  customView.requestLayout();


        return customView;
    }

尝试更改ListView单元格高度时，为什么我在模拟器上出现此错误？

1 个答案: