Question

我正在尝试在Android中创建一个简单的球和棒游戏，并为android提供以下xml文件。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".BallActivity">
<learn.com.application.BallView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/ball"/>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        >

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Left"
            android:onClick="moveleft"/>
        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Right"
            android:onClick="moveright"/>

    </LinearLayout>

</LinearLayout>

包含按钮的LinearLayout不可见，因为BallView是match_parent。但是，如果我将BallView的高度声明为wrap_content它不起作用。如何在底部显示左右按钮。还有什么方法可以用来左右移动棍子。

BallView代码

public class BallView extends android.support.v7.widget.AppCompatImageView {

    private Context mContext;
    int x = -1;
    int y = -1;
    boolean first=true;
    private int xVelocity = 10;
    private int yVelocity = 5;
    private Handler h;
    public static int FRAME_RATE = 50;
    public static int stickx=0,sticky=0;
     public static int width=0;
     public static int height=0;
     boolean gameover=false;
    public BallView(Context context,AttributeSet s) {
        super(context,s);
        mContext=context;
        h=new Handler();

    }

    private Runnable r=new Runnable() {
        @Override
        public void run() {
            invalidate();
        }
    };

    @Override
    protected void onDraw(Canvas canvas) {

if(first) {
    stickx = getWidth() / 2 - 40;
    sticky = getHeight() - 60;
    width = getWidth();
    height = getHeight();
first=false;
}
        Bitmap bmp= BitmapFactory.decodeResource(mContext.getResources(),R.drawable.ball1);
        if(x<0 && y<0)
        {
            x=getWidth()/2;
            y=getHeight()/2;
        }
        else {
            x += xVelocity;
            y += yVelocity;


            if (x + bmp.getWidth() > getWidth() || (x < 0))
                xVelocity = xVelocity * -1;


            if (y < 0)
                yVelocity = yVelocity * -1;

            if (y + bmp.getHeight() >= sticky) {
                if (x + bmp.getWidth() > stickx && x + bmp.getWidth() < (stickx + 180)) {
                    yVelocity = yVelocity * -1;
                 Log.v("ball","collision");
                }
                else {
                    Log.v("ball", "game over");

              gameover=true;
                }
            }
        }
        RectF rr=new RectF();
        int right=stickx+180;
        int bottom=sticky+30;

        rr.set(stickx,sticky,right,bottom);
        Paint p=new Paint();
        canvas.drawRoundRect(rr,5,5,p);
        canvas.drawBitmap(bmp,x,y,null);

        if(!gameover)
        h.postDelayed(r,FRAME_RATE);
    }
}

Answer 1

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".BallActivity">

    <learn.com.application.BallView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@+id/tablerow"
        android:id="@+id/ball"/>

    <TableRow
        android:id="@+id/tablerow"
        android:layout_alignParentBottom="true"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="Left"
            android:onClick="moveleft"/>
        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="Right"
            android:onClick="moveright"/>
    </TableRow>

</RelativeLayout>

我不想使用LinearLayout，而是更喜欢使用RelativeLayout和TableRow，如图所示

用android创建一个弹跳球不起作用

1 个答案: