画笔绘制屏幕移动表格

画笔、画布详细简介：

https://github.com/GcsSloop/AndroidNote/blob/master/CustomView/Advance/%5B03%5DCanvas_Convert.md

效果图：

新建一个类继承View

源码如下：

public class Table extends View {

    private Paint mPaint ; // 1.创建一个画笔
    private int lastX = 0;//记录上次X轴移动的位置
    private int lastY = 0;//记录上次Y轴移动的位置
    private  int screenWidth;//屏幕宽度
    private  int screenHeight;//屏幕高度

    /**
     * 获取屏幕宽高
     */
    public void screen(){
        DisplayMetrics dm = getResources().getDisplayMetrics();
        screenWidth=dm.widthPixels;
        screenHeight = dm.heightPixels;
    }
    public Table(Context context) {
        super(context);
        init();
        screen();
    }

    /**
     * 初始化
     */
    private void init() {
        mPaint = new Paint();
        mPaint.setColor(Color.BLACK);       //设置画笔颜色
        mPaint.setStyle(Paint.Style.FILL);  //设置画笔模式为填充
        mPaint.setStrokeWidth(5f);         //设置画笔宽度为5px
    }

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

    public Table(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    /**
     * 移动事件的处理
     * @param event
     * @return
     */
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        switch (event.getAction()){
            case MotionEvent.ACTION_DOWN://手指按下，获取当前的X，Y
                lastX = (int) event.getRawX();
                lastY = (int) event.getRawY();
                break;
            case MotionEvent.ACTION_MOVE://手指移动，计算移动单位，重新绘制当前控件
                int dx =(int)event.getRawX() - lastX;
                int dy =(int)event.getRawY() - lastY;
                int left = getLeft() + dx;
                int top = getTop() + dy;
                int right = getRight() + dx;
                int bottom = getBottom() + dy;
                if(left < 0){
                    left = 0;
                    right = left + getWidth();
                }
                if(right > screenWidth){
                    right = screenWidth;
                    left = right - getWidth();
                }
                if(top < 0){
                    top = 0;
                    bottom = top + getHeight();
                }
                if(bottom > screenHeight){
                    bottom = screenHeight;
                    top = bottom - getHeight();
                }
                layout(left, top, right, bottom);
                lastX = (int) event.getRawX();
                lastY = (int) event.getRawY();
                break;
            case MotionEvent.ACTION_UP://手指抬起
                break;
        }
        return true;
    }

    /**
     * 计算控件大小
     * @param widthMeasureSpec
     * @param heightMeasureSpec
     */
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        //设置自定义控件的大小
        setMeasuredDimension(600,600);
    }

    /**
     * 描绘方法
     * @param canvas
     */
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        canvas.drawColor(Color.WHITE); //绘制背景颜色
        canvas.drawLines(new float[]{ // 绘制一组线 每四数字(两个点的坐标)确定一条线
                0,0,600,0,
                0,200,600,200,
                0,400,600,400,
                0,600,600,600,
                0,0,0,600,
                200,0,200,600,
                400,0,400,600,
                600,0,600,600,
        },mPaint);
    }
}

在类中添加子控件即可！

public class MainActivity extends Activity {
    RelativeLayout activity_main;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
    }

    /**
     * 初始化视图
     */
    private void initView() {
        activity_main=(RelativeLayout)findViewById(R.id.activity_main);
        activity_main.addView(new Table(MainActivity.this));//添加子控件
    }
}