在 ConstraintLayout （约束布局）中，我们发现viewPager除了设置固定的尺寸外，要不就是全屏，这很不符合我们的需求，改造下：
layout中：
<MyViewPager
android:id="@+id/viewPager"
android:layout_width="0dp"
android:layout_height="wrap_content"
? android:background="@color/yellow"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/tab_layout"/>
item 布局：
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<ImageView
android:id="@+id/soon_stop_icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="28dp"
android:layout_marginTop="28dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
改造代码：
import android.content.Context; import android.util.AttributeSet; import android.view.View; import androidx.annotation.NonNull; import androidx.annotation.Nullable; import androidx.viewpager.widget.ViewPager;
/**
* mwt,自适应高
*/
public class MyViewPager extends ViewPager {
public MyViewPager(@NonNull Context context) {
this(context, null);
}
public MyViewPager(@NonNull Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int height = 0;
for (int i = 0; i < getChildCount(); i++) {
View child = getChildAt(i);
child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
int h = child.getMeasuredHeight();
if (h > height)
height = h;
}
heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
效果：
