Question

我使用的是具有RelativeLayout - ＆gt;的视图ScrollView - ＆gt; LinearLayout中。我得到例外：

11-22 11:17:24.605: ERROR/AndroidRuntime(5161): FATAL EXCEPTION: main
11-22 11:17:24.605: ERROR/AndroidRuntime(5161): java.lang.ClassCastException: android.view.ViewGroup$LayoutParams
11-22 11:17:24.605: ERROR/AndroidRuntime(5161):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3131)
11-22 11:17:24.605: ERROR/AndroidRuntime(5161):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:245)
11-22 11:17:24.605: ERROR/AndroidRuntime(5161):     at android.view.View.measure(View.java:8172)
11-22 11:17:24.605: ERROR/AndroidRuntime(5161):     at android.view.ViewRoot.performTraversals(ViewRoot.java:805)
11-22 11:17:24.605: ERROR/AndroidRuntime(5161):     at android.view.ViewRoot.handleMessage(ViewRoot.java:1744)
11-22 11:17:24.605: ERROR/AndroidRuntime(5161):     at android.os.Handler.dispatchMessage(Handler.java:99)
11-22 11:17:24.605: ERROR/AndroidRuntime(5161):     at android.os.Looper.loop(Looper.java:144)
11-22 11:17:24.605: ERROR/AndroidRuntime(5161):     at android.app.ActivityThread.main(ActivityThread.java:4937)
11-22 11:17:24.605: ERROR/AndroidRuntime(5161):     at java.lang.reflect.Method.invokeNative(Native Method)
11-22 11:17:24.605: ERROR/AndroidRuntime(5161):     at java.lang.reflect.Method.invoke(Method.java:521)
11-22 11:17:24.605: ERROR/AndroidRuntime(5161):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
11-22 11:17:24.605: ERROR/AndroidRuntime(5161):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
11-22 11:17:24.605: ERROR/AndroidRuntime(5161):     at dalvik.system.NativeStart.main(Native Method)

为什么它只是偶尔发生？为什么没有详细的代码失败的地方？

更新：我怀疑这个代码应该失败：

EditText input = new EditText(context);
input.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));

LayoutParams是RelativeLayout.LayoutParams

Answer 1

使用new LinearLayout.LayoutParams(...)代替new LayoutParams(...)

您始终需要使用LayoutParams的父布局类。例如。如果EditText位于FrameLayout内，则必须使用FrameLayout.LayoutParams。

java.lang.ClassCastException：没有LayoutParams用法的android.view.ViewGroup $ LayoutParams

1 个答案: