Question

我有一个带有ExpandableListView的应用程序，每个标题都有自己的drawable作为背景。这是代码：

if (Build.VERSION.SDK_INT > Build.VERSION_CODES.HONEYCOMB);
    {
        switch(groupPosition){
        case 0:
            convertView.setBackground(this._context.getResources().getDrawable(R.drawable.light_blue));
            break;
        case 1:
            convertView.setBackground(this._context.getResources().getDrawable(R.drawable.drugi_letniki_color));
            break;
        case 2:
            convertView.setBackground(this._context.getResources().getDrawable(R.drawable.light_blue));
            break;
        case 3:
            convertView.setBackground(this._context.getResources().getDrawable(R.drawable.cetrti_letniki_color));
            break;
        }
    }

这在我的三星Galaxy Nexus上使用Android 4.3完全正常，但是当我在Android版本2.2的模拟器上试用它时会崩溃。

这是logcat文件：

09-05 20:46:45.914: E/AndroidRuntime(371): FATAL EXCEPTION: main
09-05 20:46:45.914: E/AndroidRuntime(371): java.lang.NoSuchMethodError: android.view.View.setBackground
09-05 20:46:45.914: E/AndroidRuntime(371):  at com.whizzapps.stpsurniki.ExpandableListAdapter.getGroupView(ExpandableListAdapter.java:100)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.widget.ExpandableListConnector.getView(ExpandableListConnector.java:445)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.widget.HeaderViewListAdapter.getView(HeaderViewListAdapter.java:220)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.widget.AbsListView.obtainView(AbsListView.java:1315)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.widget.ListView.makeAndAddView(ListView.java:1727)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.widget.ListView.fillDown(ListView.java:652)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.widget.ListView.fillFromTop(ListView.java:709)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.widget.ListView.layoutChildren(ListView.java:1580)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.widget.AbsListView.onLayout(AbsListView.java:1147)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.view.View.layout(View.java:7035)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1249)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.widget.LinearLayout.layoutHorizontal(LinearLayout.java:1238)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.widget.LinearLayout.onLayout(LinearLayout.java:1044)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.view.View.layout(View.java:7035)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.widget.FrameLayout.onLayout(FrameLayout.java:333)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.view.View.layout(View.java:7035)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1249)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1125)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.widget.LinearLayout.onLayout(LinearLayout.java:1042)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.view.View.layout(View.java:7035)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.widget.FrameLayout.onLayout(FrameLayout.java:333)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.view.View.layout(View.java:7035)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.view.ViewRoot.performTraversals(ViewRoot.java:1045)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.view.ViewRoot.handleMessage(ViewRoot.java:1727)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.os.Handler.dispatchMessage(Handler.java:99)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.os.Looper.loop(Looper.java:123)
09-05 20:46:45.914: E/AndroidRuntime(371):  at android.app.ActivityThread.main(ActivityThread.java:4627)
09-05 20:46:45.914: E/AndroidRuntime(371):  at java.lang.reflect.Method.invokeNative(Native Method)
09-05 20:46:45.914: E/AndroidRuntime(371):  at java.lang.reflect.Method.invoke(Method.java:521)
09-05 20:46:45.914: E/AndroidRuntime(371):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
09-05 20:46:45.914: E/AndroidRuntime(371):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
09-05 20:46:45.914: E/AndroidRuntime(371):  at dalvik.system.NativeStart.main(Native Method)

这是第100行：

convertView.setBackground(this._context.getResources().getDrawable(R.drawable.light_blue));

正如您所看到的，我已经尝试通过在旧版本上禁用自定义背景来解决问题，但似乎忽略了if语句。

编辑：如果有人仍然想知道我是如何解决问题的;这是代码：

if (Build.VERSION.SDK_INT >= 16)
    {
        switch(groupPosition){
        case 0:
            convertView.setBackground(this._context.getResources().getDrawable(R.drawable.light_blue));
            break;
        case 1:
            convertView.setBackground(this._context.getResources().getDrawable(R.drawable.drugi_letniki_color));
            break;
        case 2:
            convertView.setBackground(this._context.getResources().getDrawable(R.drawable.light_blue));
            break;
        case 3:
            convertView.setBackground(this._context.getResources().getDrawable(R.drawable.cetrti_letniki_color));
            break;
        }
    }
    else if (Build.VERSION.SDK_INT < 16)
    {
        switch(groupPosition){
        case 0:
            convertView.setBackgroundDrawable(this._context.getResources().getDrawable(R.drawable.light_blue));
            break;
        case 1:
            convertView.setBackgroundDrawable(this._context.getResources().getDrawable(R.drawable.drugi_letniki_color));
            break;
        case 2:
            convertView.setBackgroundDrawable(this._context.getResources().getDrawable(R.drawable.light_blue));
            break;
        case 3:
            convertView.setBackgroundDrawable(this._context.getResources().getDrawable(R.drawable.cetrti_letniki_color));
            break;
        }
    }

这是因为.setBackgroundDrawable在API 1及更高版本上可用，而.setBackground仅在API 16及更高版本上可用

Answer 1

检查可能无效，因为2.2中未定义Build.VERSION_CODES.HONEYCOMB。

如果你想进行检查，你只需要使用常数。

修改

此外，在if声明后面有一个分号。你应该删除它，这样你的条件实际上会控制你是否进入if语句的代码块。

应用程序崩溃旧版Android（ExpandableListView自定义绘图）

1 个答案: