以编程方式设置滚动视图的布局参数时出现异常

Posted 2023-02-26

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【中文标题】以编程方式设置滚动视图的布局参数时出现异常【英文标题】：Getting exception while setting layoutparams of scrollview programmatically 【发布时间】：2012-09-23 06:49:39 【问题描述】：

我在以编程方式设置 scroolview 的 layoutparams 时遇到异常。我已经尝试过，但在执行此操作时遇到异常。这是代码：

sv = (ScrollView)findViewById(R.id.scrollView);
        sv.setBackgroundColor(Color.TRANSPARENT);

            ScrollView.LayoutParams layoutParams = new ScrollView.LayoutParams(
                    ScrollView.LayoutParams.MATCH_PARENT,
                    ScrollView.LayoutParams.MATCH_PARENT);
            layoutParams.bottomMargin = 100;
            layoutParams.setMargins(0, 0, 0, 100);
            sv.setLayoutParams(layoutParams);

这是错误日志：

09-23 12:13:20.666: E/androidRuntime(3284): Uncaught handler: thread main exiting due to uncaught exception
09-23 12:13:20.696: E/AndroidRuntime(3284): java.lang.ClassCastException: android.widget.FrameLayout$LayoutParams
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.widget.RelativeLayout$DependencyGraph.findRoots(RelativeLayout.java:1291)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.widget.RelativeLayout$DependencyGraph.getSortedViews(RelativeLayout.java:1238)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.widget.RelativeLayout.sortChildren(RelativeLayout.java:279)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:299)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.view.View.measure(View.java:7964)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:569)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:361)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.view.View.measure(View.java:7964)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3023)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:245)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.view.View.measure(View.java:7964)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.widget.LinearLayout.measureVertical(LinearLayout.java:464)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.widget.LinearLayout.onMeasure(LinearLayout.java:278)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.view.View.measure(View.java:7964)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3023)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:245)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.view.View.measure(View.java:7964)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3023)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:245)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.view.View.measure(View.java:7964)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.view.ViewRoot.performTraversals(ViewRoot.java:763)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.view.ViewRoot.handleMessage(ViewRoot.java:1633)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.os.Handler.dispatchMessage(Handler.java:99)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.os.Looper.loop(Looper.java:123)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at android.app.ActivityThread.main(ActivityThread.java:4363)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at java.lang.reflect.Method.invokeNative(Native Method)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at java.lang.reflect.Method.invoke(Method.java:521)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
09-23 12:13:20.696: E/AndroidRuntime(3284):     at dalvik.system.NativeStart.main(Native Method)

这是xml文件：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:ads="http://schemas.android.com/apk/lib/com.google.ads"
    android:layout_
    android:layout_
    android:layout_centerHorizontal="true"
    android:orientation="vertical" >

    <RelativeLayout
        android:id="@+id/frameLayout"
        android:layout_
        android:layout_ >

        <ScrollView
            android:id="@+id/scrollView"
            android:layout_
            android:layout_
            android:layout_marginBottom="90.0dip"
            android:layout_marginLeft="1.0dip"
            android:layout_marginRight="1.0dip"
            android:layout_marginTop="-2.0dip"
            android:animateLayoutChanges="true"
            android:fadeScrollbars="true"
            android:fadingEdge="none" >

            <!-- android:layout_marginBottom="60.0dip" -->
            <!-- android:fillViewport="true" -->

            <RelativeLayout
                android:layout_
                android:layout_
                android:orientation="vertical"
                android:visibility="visible" >

                <ImageView
                    android:id="@+id/QuestionImageView"
                    android:layout_
                    android:layout_
                    android:visibility="visible" />

                <TextView
                    android:id="@+id/tv"
                    android:layout_
                    android:layout_
                    android:layout_below="@id/QuestionImageView"
                    android:fadingEdge="vertical"
                    android:scrollbars="vertical" />

                <TextView
                    android:id="@+id/questionnumber"
                    android:layout_
                    android:layout_
                    android:layout_alignParentRight="true"
                    android:fadingEdge="vertical"
                    android:scrollbars="vertical" />

                <TextView
                    android:id="@+id/question"
                    android:layout_
                    android:layout_
                    android:layout_alignParentRight="true"
                    android:layout_below="@id/tv"
                    android:fadingEdge="vertical"
                    android:padding="10dp"
                    android:scrollbars="vertical"
                    android:text=""
                    android:textColor="@color/dark_green" />

                <RadioGroup
                    android:id="@+id/radioGroup1"
                    android:layout_
                    android:layout_
                    android:layout_below="@id/question"
                    android:orientation="vertical" >

                    <RadioButton
                        android:id="@+id/option1"
                        android:layout_
                        android:layout_
                        android:text="" />

                    <ImageView
                        android:layout_
                        android:layout_
                        android:background="@drawable/thinnest_blue_gradient" />

                    <RadioButton
                        android:id="@+id/option2"
                        android:layout_
                        android:layout_
                        android:text="" />

                    <ImageView
                        android:layout_
                        android:layout_
                        android:background="@drawable/thinnest_blue_gradient" />

                    <RadioButton
                        android:id="@+id/option3"
                        android:layout_
                        android:layout_
                        android:text="" />

                    <ImageView
                        android:layout_
                        android:layout_
                        android:background="@drawable/thinnest_blue_gradient" />

                    <RadioButton
                        android:id="@+id/option4"
                        android:layout_
                        android:layout_
                        android:text="" />
                </RadioGroup>
            </RelativeLayout>
        </ScrollView>
    </RelativeLayout>

    <RelativeLayout
        android:id="@+id/relativequestion"
        android:layout_
        android:layout_
        android:layout_alignParentBottom="true" >

        <com.google.ads.AdView
            android:id="@+id/ad"
            android:layout_
            android:layout_
            android:layout_alignParentBottom="true"
            ads:adSize="SMART_BANNER"
            ads:adUnitId="a1501e5633125fb"
            ads:loadAdOnCreate="true"
            ads:testDevices="TEST_EMULATOR, 123456789ABCDEF" />

        <LinearLayout
            android:id="@+id/newquestion"
            android:layout_
            android:layout_
            android:layout_above="@id/ad"
            android:background="#ff777777"
            android:orientation="horizontal" >

            <Button
                android:id="@+id/PrevButton"
                android:layout_
                android:layout_
                android:layout_centerInParent="true"
                android:layout_marginLeft="5.0dip"
                android:layout_weight="1.0"
                android:background="@drawable/ibtn"
                android:onClick="onPrevButtonClick"
                android:text="Prev" />

            <Button
                android:id="@+id/NextButton"
                android:layout_
                android:layout_
                android:layout_centerInParent="true"
                android:layout_marginLeft="5.0dip"
                android:layout_weight="1.0"
                android:background="@drawable/ibtn"
                android:onClick="onNextButtonClick"
                android:text="Next" />

            <Button
                android:id="@+id/SkipButton"
                android:layout_
                android:layout_
                android:layout_centerInParent="true"
                android:layout_marginLeft="5.0dip"
                android:layout_weight="1.0"
                android:background="@drawable/ibtn"
                android:onClick="onSkipButtonClick"
                android:text="Skip" >
            </Button>

            <Button
                android:id="@+id/SubmitButton"
                android:layout_
                android:layout_
                android:layout_centerInParent="true"
                android:layout_marginLeft="5.0dip"
                android:layout_marginRight="5.0dp"
                android:layout_weight="1.0"
                android:background="@drawable/ibtn"
                android:onClick="onSubmitButtonClick"
                android:text="Submit" />
        </LinearLayout>
    </RelativeLayout>

</RelativeLayout>

请帮助我。在此先感谢。

【问题讨论】：

【参考方案1】：

您的ScrollView 的父级是RelativeLayout，为此您应该使用RelativeLayout.LayoutParams：

    RelativeLayout.LayoutParams lp = (RelativeLayout.LayoutParams) sv
            .getLayoutParams();
    lp.setMargins(0, 0, 0, 100);

【讨论】：

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