我想用这种结构做一个活动:
这个想法是在顶部放置一些文本,始终在顶部放置横幅,将按钮放在横幅上方,将我的画布放在视图的中心,使用所有可能的空间。
我将 View 子类化以绘制我的画布并重载 onMeasure() 方法:
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// Calculate the size of the board
this.squareSize = MeasureSpec.getSize(widthMeasureSpec) / BOARD_NUM_ROWS;
this.leftMargin = (MeasureSpec.getSize(widthMeasureSpec) - squareSize*BOARD_NUM_COLUMNS) / 2;
this.topMargin = this.leftMargin;
// Set the size of the board to full width and aspect ratio height
int desiredWidth = MeasureSpec.getSize(widthMeasureSpec);
int desiredHeight = this.topMargin + (BOARD_NUM_ROWS * this.squareSize) + this.topMargin;
this.setMeasuredDimension(desiredWidth, desiredHeight);
}
这是我的 XML:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:ads="http://schemas.android.com/apk/lib/com.google.ads"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
tools:context=".DrawLevelActivity"
android:background="@color/activity_background">
<TextView
android:id="@+id/instructionsText"
android:gravity="center"
android:paddingTop="10dp"
android:paddingBottom="10dp"
android:paddingLeft="0dp"
android:paddingRight="0dp"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
<com.mycanvas.BoardCanvas
android:id="@+id/boardCanvas"
android:gravity="center"
android:layout_below="@+id/instructionsText"
android:layout_centerVertical="true"
android:padding="0dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<Button
android:id="@+id/solveButton"
android:gravity="center"
android:paddingTop="10dp"
android:paddingBottom="10dp"
android:paddingLeft="30dp"
android:paddingRight="30dp"
android:layout_below="@+id/boardCanvas"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>
<com.google.ads.AdView
xmlns:googleads="http://schemas.android.com/apk/lib/com.google.ads"
android:id="@+id/adView"
android:gravity="center"
android:paddingTop="0dp"
android:paddingBottom="0dp"
android:paddingLeft="0dp"
android:paddingRight="0dp"
android:layout_alignParentBottom="true"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
googleads:adSize="BANNER"
googleads:adUnitId="@string/admob_id" />
</RelativeLayout>
不幸的是,按钮出现在横幅下,我认为原因是画布非常大。
onMeasure() 中的设置值总是小于 MeasureSpec.getSize(heightMeasureSpec)