4

我想更改第一个 layout_marginStart 而 layout_marginStart 不应该更改直到第 60 帧。但是以下关键帧被忽略并且两个边距同时动画。

<MotionScene xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">


    <Transition

        app:constraintSetEnd="@+id/end"
        app:constraintSetStart="@+id/start"

        >
        <OnSwipe
            app:dragDirection="dragUp"
            app:touchAnchorId="@id/scrollable"
            app:touchAnchorSide="top" />
        <KeyFrameSet>
            <KeyAttribute
                app:curveFit="linear"
                app:framePosition="10"
                app:motionTarget="@+id/text">
                <CustomAttribute
                    app:attributeName="layoutMarginStart"
                    app:customDimension="68dip" />
            </KeyAttribute>
            <KeyAttribute
                app:curveFit="linear"
                app:framePosition="60"
                app:motionTarget="@+id/text">
                <CustomAttribute
                    app:attributeName="layoutMarginEnd"
                    app:customDimension="0dip" />
            </KeyAttribute>

        </KeyFrameSet>
        <ConstraintSet android:id="@+id/start">
            <Constraint
                android:id="@+id/text"
                android:layout_width="0dip"
                android:layout_height="40dip"
                android:layout_marginStart="16dip"

                android:layout_marginTop="24dip"
                android:layout_marginEnd="16dip"
                android:layout_marginBottom="12dip"
                android:background="#BEBEBE"
                app:layout_constraintEnd_toEndOf="@+id/parent"
                app:layout_constraintStart_toStartOf="@+id/parent"
                app:layout_constraintTop_toTopOf="parent" />


        </ConstraintSet>

        <ConstraintSet android:id="@+id/end">
            <Constraint
                android:id="@+id/text"
                android:layout_width="0dip"
                android:layout_height="40dip"
                android:layout_marginStart="60dip"
                android:layout_marginTop="24dip"
                android:layout_marginEnd="60dip"
                android:layout_marginBottom="12dip"
                android:background="#BEBEBE"
                app:layout_constraintEnd_toEndOf="@+id/parent"
                app:layout_constraintStart_toStartOf="@+id/parent"
                app:layout_constraintTop_toTopOf="parent" />


        </ConstraintSet>
    </Transition>

</MotionScene>
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1 回答 1

0

您的视图上没有setLayoutMarginStart或setLayoutMarginEnd方法。该app:attributeName参数将通过反射工作并搜索这些方法。

实现这一点的一种方法是简单地将您的视图子类化并编写您自己的设置器。

fun setMarginTop(newMarginTop: Int) {
    val lp = layoutParams as? ViewGroup.MarginLayoutParams ?: return
    lp.run { 
        setMargins(leftMargin, newMarginTop, rightMargin, bottomMargin)
    }
    layoutParams = lp
}

或者，如果您使用 kotlin-ktx：

fun setMarginTop(newMarginTop: Int) {
    updateLayoutParams<ViewGroup.MarginLayoutParams> {
        updateMargins(top = newMarginTop)
    }
}
于 2019-06-02T13:33:14.470 回答