pushbox(1)

画出矩形，并能通过键盘控制小方块在矩形内移动

MainActivity.java

package cn.lesson.test;

import android.app.Activity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.MotionEvent;

public class MainActivity extends Activity {
    private TestView pushBox = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        pushBox = new TestView(this);
        super.onCreate(savedInstanceState);
        setContentView(pushBox);
    }    
   
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_DPAD_UP) {
            TestView.y--;
            TestView.reset(9, 9);
        } else if (keyCode == KeyEvent.KEYCODE_DPAD_DOWN) {
            TestView.y++;
            TestView.reset(9, 9);
        }
        if (keyCode == KeyEvent.KEYCODE_DPAD_LEFT) {
            TestView.x--;
            TestView.reset(9, 9);
        }
        if (keyCode == KeyEvent.KEYCODE_DPAD_RIGHT) {
            TestView.x++;
            TestView.reset(9, 9);
        }
        pushBox.invalidate();
        return super.onKeyDown(keyCode, event);
    }
}

TestView.java

package cn.lesson.test;

import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;

public class TestView extends View {
    public TestView(Context context) {
        super(context);
    }

    public TestView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    private static int height = 30;
    private static int width = 30;

    public static int x = 0;
    public static int y = 0;

    public static boolean check(int W, int H) {
        if (TestView.x < H && TestView.y < W && TestView.y > 0
                && TestView.x > 0) {
            return true;
        }
        return false;
    }

    public static void reset(int W, int H) {
        if (!check(W, H)) {
            if (TestView.x >= H) {
                TestView.x = 0;
            }
            if (TestView.x < 0) {
                TestView.x = H - 1;
            }
            if (TestView.y >= W) {
                TestView.y = 0;
            }
            if (TestView.y < 0) {
                TestView.y = W - 1;
            }
        }
    }
    @SuppressLint("DrawAllocation")
    @Override
    protected void onDraw(Canvas canvas) {
        Log.d("onDraw:", "x:" + x + "y:" + y);
        Paint paint = new Paint();
        Drawable dw = this.getResources().getDrawable(R.drawable.bg);
        dw.setBounds(0, 0, height, width);
        Bitmap bitMap = Bitmap.createBitmap(100, 100, Bitmap.Config.ARGB_8888);
        Canvas cs = new Canvas(bitMap);
        dw.draw(cs);

        paint.setColor(Color.CYAN);
        canvas.drawBitmap(bitMap, height * (x + 1), width * (y + 1), paint);
        canvas.drawLine(30f, 30f, 300f, 30f, paint);
        canvas.drawLine(30f, 30f, 30f, 300f, paint);
        canvas.drawLine(300f, 30f, 300f, 300f, paint);
        canvas.drawLine(30f, 300f, 300f, 300f, paint);

        Bitmap left = BitmapFactory.decodeResource(getResources(),
                R.drawable.left);
        Bitmap right = BitmapFactory.decodeResource(getResources(),
                R.drawable.right);
        Bitmap up = BitmapFactory.decodeResource(getResources(), R.drawable.up);
        Bitmap down = BitmapFactory.decodeResource(getResources(),
                R.drawable.down);

        canvas.drawBitmap(left, 50, 320, paint);
        canvas.drawBitmap(up, 100, 320, paint);
        canvas.drawBitmap(down, 150, 320, paint);
        canvas.drawBitmap(right, 200, 320, paint);
        super.onDraw(canvas);
    }
}

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <cn.lesson.test.TestView
        android:id="@+id/testView"
        android:layout_width="100dip"
        android:layout_height="100dip"
        />
</RelativeLayout>