Question

当我尝试以编程方式向我的NullPointerException添加夸大的观看次数时，我收到了ViewFlipper：

- onCreate

setContentView(R.layout.event_report);

final LayoutInflater inflater = getLayoutInflater();
mFlipper = (ViewFlipper) findViewById(R.id.eventReportViewFlipper);

final View typeView = inflater
            .inflate(R.layout.event_report_type, null)
mFlipper.addView(typeView, VIEW_TYPE, null); //NullPointerException

- event_report.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@android:color/darker_gray"
    android:orientation="vertical">
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:background="@android:color/background_dark"
        android:gravity="center"
        android:text="@string/eventReportCaption"
        android:textAppearance="?android:attr/textAppearanceLarge"/>
    <ViewFlipper
        android:id="@+id/eventReportViewFlipper"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"/>
</LinearLayout>

- event_report_type.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical">
    <LinearLayout
        android:id="@+id/eventReportViewTypeUpperLayout"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_weight="1"
        android:orientation="horizontal">
        <Button
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:layout_weight="1"/>
        <Button
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:layout_weight="1"/>
    </LinearLayout>
    <LinearLayout
        android:id="@+id/eventReportViewTypeLowerLayout"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_weight="1"
        android:orientation="horizontal">
        <Button
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:layout_weight="1"/>
        <Button
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:layout_weight="1"/>
    </LinearLayout>
</LinearLayout>

我计划稍后初始化typeView。

这是我的堆栈跟踪：

11-28 16:59:56.280: E/AndroidRuntime(8604): Caused by: java.lang.NullPointerException
11-28 16:59:56.280: E/AndroidRuntime(8604):     at android.view.ViewGroup$LayoutParams.<init>(ViewGroup.java:3582)
11-28 16:59:56.280: E/AndroidRuntime(8604):     at android.view.ViewGroup$MarginLayoutParams.<init>(ViewGroup.java:3732)
11-28 16:59:56.280: E/AndroidRuntime(8604):     at android.widget.FrameLayout$LayoutParams.<init>(FrameLayout.java:492)
11-28 16:59:56.280: E/AndroidRuntime(8604):     at android.widget.FrameLayout.generateLayoutParams(FrameLayout.java:436)
11-28 16:59:56.280: E/AndroidRuntime(8604):     at android.view.ViewGroup.addViewInner(ViewGroup.java:1984)
11-28 16:59:56.280: E/AndroidRuntime(8604):     at android.view.ViewGroup.addView(ViewGroup.java:1874)
11-28 16:59:56.280: E/AndroidRuntime(8604):     at android.widget.ViewAnimator.addView(ViewAnimator.java:160)
11-28 16:59:56.280: E/AndroidRuntime(8604):     at fi.emicode.flashpoint.EventDialog.onCreate(EventDialog.java:43)

Answer 1

这是来自Android文档的addView方法

addView(View child, int index, ViewGroup.LayoutParams params)

是类型为int的VIEW_TYPE吗？

我认为您应该为添加的视图指定layoutparams或仅使用addView 2个参数

addView(VIEW_TYPE,index);

在Android中向ViewFlipper动态添加膨胀视图会导致NullPointerException

1 个答案: