Android自定义view摇杆,Android自定义View实现游戏摇杆键盘的方法示例

前言

本文主要给大家介绍的是关于Android自定义View实现游戏摇杆键盘的相关内容，为什么会有这篇文章呢？因为在之前的一个项目，操作方向的方式为上下左右，左上需要同时按住左键和右键的方式进行操作。

如下图：

近来需要升级项目，操作方式改为类似王者荣耀的摇杆操作。

如下图：

好了，下面话不多说了，跟着小编来一起看看是如何实现的吧。

绘制背景

实现遥感按钮，需要绘制背景，绘制中心的遥感按钮。绘制遥感背景，需要创建一个RemoteViewBg类，存储背景图，减少重复创建bitmap。

RemoteViewBg类代码如下：

public class RemoteViewBg {

private Bitmap bitmapBg;

public RemoteViewBg(Bitmap bitmap) {

bitmapBg = bitmap;

}

//背景的绘图函数

public void draw(Canvas canvas, Paint paint, Rect src0 ,Rect dst0 ) {

canvas.drawBitmap(bitmapBg, src0, dst0, paint);

}

}

点击触摸事件

重写系统的触摸时间，判断触摸点在背景范围内还是背景范围外

@Override

public boolean onTouchEvent(MotionEvent event) {

if (event.getAction() == MotionEvent.ACTION_DOWN || event.getAction() == MotionEvent.ACTION_MOVE) {

// // 在范围外触摸

if (Math.sqrt(Math.pow((bigCircleX - (int) event.getX()), 2) + Math.pow((bigCircleY - (int) event.getY()), 2)) >= bigCircleR) {

double tempRad = getRad(bigCircleX, bigCircleY, event.getX(), event.getY());

getXY(bigCircleX, bigCircleY, bigCircleR, tempRad);

} else {//范围内触摸

smallCircleX = (int) event.getX();

smallCircleY = (int) event.getY();

}

} else if (event.getAction() == MotionEvent.ACTION_UP) {

smallCircleX = bigCircleX;

smallCircleY = bigCircleY;

}

return true;

}

弧度计算

通过 event.getX(), event.getY()获得当前的触摸点，与圆点进行计算，获取弧度

/***

* 得到两点之间的弧度

*/

public float getRad(float px1, float py1, float px2, float py2) {

float x = px2 - px1;

float y = py1 - py2;

//斜边的长

float z = (float) Math.sqrt(Math.pow(x, 2) + Math.pow(y, 2));

float cosAngle = x / z;

float rad = (float) Math.acos(cosAngle);

if (py2 < py1) {

rad = -rad;

}

return rad;

}

图形绘制

通过 canvas.drawCircle()和 canvas.drawBitmap()分别进行遥感按钮和遥感背景的绘制，注意对遥感背景的保存，如果在绘制的时候每次BitmapFactory.decodeResource()会增加耗时，因此只需在surfaceCreated()中进行bitmap的生成即可。

public void draw() {

try {

canvas = sfh.lockCanvas();

canvas.drawColor(getResources().getColor(R.color.ghostwhite));

// 指定图片绘制区域(左上角的四分之一)

Rect src = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());

// 指定图片在屏幕上显示的区域

Rect dst = new Rect(bigCircleX - bigCircleR, bigCircleY - bigCircleR, bigCircleX + bigCircleR, bigCircleY + bigCircleR);

// 绘制图片

remoteViewBg.draw(canvas, paint, src, dst);

paint.setColor(0x70ff0000);

//绘制摇杆

canvas.drawCircle(smallCircleX, smallCircleY, smallCircleR, paint);

} catch (Exception e) {

// TODO: handle exception

} finally {

try {

if (canvas != null)

sfh.unlockCanvasAndPost(canvas);

} catch (Exception e2) {

e2.printStackTrace();

}

}

}

使用

在activity中动态添加

RelativeLayout relativeLayout = (RelativeLayout) findViewById(R.id.dance_relative_layout);

remoteSurfaceView = new RemoteSurfaceView(this);

params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT,

RelativeLayout.LayoutParams.MATCH_PARENT);

remoteSurfaceView.setLayoutParams(params);

relativeLayout.addView(remoteSurfaceView);

全部代码

public class RemoteSurfaceView extends SurfaceView implements Callback, Runnable {

private float scale = this.getResources().getDisplayMetrics().density;

private Thread th;

private SurfaceHolder sfh;

private Canvas canvas;

private Paint paint;

private boolean flag;

private int bigCircleX = 0;

private int bigCircleY =0;

private int bigCircleR = 0;

//摇杆的X,Y坐标以及摇杆的半径

private float smallCircleX = 0;

private float smallCircleY = 0;

private float smallCircleR = 0;

private Bitmap bitmap;

private RemoteViewBg remoteViewBg;

public RemoteSurfaceView(Context context) {

super(context);

sfh = this.getHolder();

sfh.addCallback(this);

paint = new Paint();

paint.setAntiAlias(true);

setFocusable(true);

setFocusableInTouchMode(true);

setZOrderOnTop(true);

getHolder().setFormat(PixelFormat.TRANSPARENT);

}

public void surfaceCreated(SurfaceHolder holder) {

int width = getWidth();

int height = getHeight();

bigCircleX = width / 2;

bigCircleY = height / 2;

bigCircleR = width / 4;

smallCircleX = width / 2;

smallCircleY = height / 2;

smallCircleR = width / 8;

bitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.fangxiang);

remoteViewBg = new RemoteViewBg(bitmap);

th = new Thread(this);

flag = true;

th.start();

}

/***

* 得到两点之间的弧度

*/

public float getRad(float px1, float py1, float px2, float py2) {

float x = px2 - px1;

float y = py1 - py2;

//斜边的长

float z = (float) Math.sqrt(Math.pow(x, 2) + Math.pow(y, 2));

float cosAngle = x / z;

float rad = (float) Math.acos(cosAngle);

if (py2 < py1) {

rad = -rad;

}

return rad;

}

@Override

public boolean onTouchEvent(MotionEvent event) {

if (event.getAction() == MotionEvent.ACTION_DOWN || event.getAction() == MotionEvent.ACTION_MOVE) {

// 在范围外触摸

if (Math.sqrt(Math.pow((bigCircleX - (int) event.getX()), 2) + Math.pow((bigCircleY - (int) event.getY()), 2)) >= bigCircleR) {

double tempRad = getRad(bigCircleX, bigCircleY, event.getX(), event.getY());

getXY(bigCircleX, bigCircleY, bigCircleR, tempRad);

} else {//范围内触摸

smallCircleX = (int) event.getX();

smallCircleY = (int) event.getY();

}

} else if (event.getAction() == MotionEvent.ACTION_UP) {

smallCircleX = bigCircleX;

smallCircleY = bigCircleY;

}

return true;

}

public void getXY(float x, float y, float R, double rad) {

//获取圆周运动的X坐标

smallCircleX = (float) (R * Math.cos(rad)) + x;

//获取圆周运动的Y坐标

smallCircleY = (float) (R * Math.sin(rad)) + y;

}

public void draw() {

try {

canvas = sfh.lockCanvas();

canvas.drawColor(getResources().getColor(R.color.ghostwhite));

// 指定图片绘制区域(左上角的四分之一)

Rect src = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());

// 指定图片在屏幕上显示的区域

Rect dst = new Rect(bigCircleX - bigCircleR, bigCircleY - bigCircleR, bigCircleX + bigCircleR, bigCircleY + bigCircleR);

// 绘制图片

remoteViewBg.draw(canvas, paint, src, dst);

paint.setColor(0x70ff0000);

//绘制摇杆

canvas.drawCircle(smallCircleX, smallCircleY, smallCircleR, paint);

} catch (Exception e) {

// TODO: handle exception

} finally {

try {

if (canvas != null)

sfh.unlockCanvasAndPost(canvas);

} catch (Exception e2) {

e2.printStackTrace();

}

}

}

public void run() {

while (flag) {

draw();

try {

Thread.sleep(50);

} catch (Exception ex) {

ex.printStackTrace();

}

}

}

public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

}

public void surfaceDestroyed(SurfaceHolder holder) {

flag = false;

}

}

总结

以上就是这篇文章的全部内容，希望本文的内容对大家的学习或者工作能带来一定的帮助，如果有疑问大家可以留言交流，谢谢大家对脚本之家的支持。