本文实例为大家分享了Android贝塞尔曲线实现手指轨迹的具体代码，供大家参考，具体内容如下

1、使用贝塞尔曲线前

MyView.java

public class MyView extends View { // 实例一个路径对象 private Path mPath = new Path(); public MyView(Context context) { super(context); // TODO Auto-generated constructor stub } public MyView(Context context, AttributeSet attrs) { super(context, attrs); } @Override public boolean onTouchEvent(MotionEvent event) { // TODO Auto-generated method stub switch (event.getAction()) { // 按下 case MotionEvent.ACTION_DOWN: //getX()和getY()获得的永远是相对view的触摸位置坐标 mPath.moveTo(event.getX(), event.getY()); // return true表示当前控件已经消费了下按动作， // 之后的ACTION_MOVE、ACTION_UP动作也会继续传递到当前控件中 return true; // 移动 case MotionEvent.ACTION_MOVE: mPath.lineTo(event.getX(), event.getY()); // postInvalidate用来重绘控件,在非UI线程中使用 postInvalidate(); default: break; } return super.onTouchEvent(event); } @Override protected void onDraw(Canvas canvas) { // TODO Auto-generated method stub super.onDraw(canvas); // 实例一个画笔并设置画笔样式 Paint paint = new Paint(); paint.setColor(Color.RED); paint.setStyle(Paint.Style.STROKE);// 填充样式改为描边 // 路径和画笔联合绘制成图形 canvas.drawPath(mPath, paint); } public void reset() { // 清除掉path里的线条和曲线，但是不会改变它的fill－type mPath.reset(); //刷新View,清屏 invalidate(); }}

MyActivity.java

public class MyActivity extends Activity { MyView myView; Button reset; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.gesture); myView = (MyView) findViewById(R.id.myView); reset = (Button) findViewById(R.id.reset); reset.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub myView.reset(); } }); }}

gesture.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <Button android:id="@+id/reset" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="reset" /> <com.example.gesture.MyView android:id="@+id/myView" android:layout_width="match_parent" android:layout_height="match_parent" /></LinearLayout>

运行效果（不够顺滑）

2、使用贝塞尔曲线后

将上面函数lineTo（）改为quadTo（）

public class MySecondView extends View { private Path mPath=new Path(); private float mPreX,mPreY; public MySecondView(Context context) { super(context); } public MySecondView(Context context, AttributeSet attrs) { super(context, attrs); // TODO Auto-generated constructor stub } @Override public boolean onTouchEvent(MotionEvent event) { // TODO Auto-generated method stub switch (event.getAction()) { case MotionEvent.ACTION_DOWN: //将Path的初始位置设置到手指的触点处 mPath.moveTo(event.getX(), event.getY()); mPreX=event.getX(); mPreY=event.getY(); return true; case MotionEvent.ACTION_MOVE: float endX=(mPreX+event.getX())/2; float endY=(mPreY+event.getY())/2; //quadTo前两个参数是控制点，后两个是终点 mPath.quadTo(mPreX, mPreY, endX, endY); mPreX=event.getX(); mPreY=event.getY(); invalidate(); default: break; } return super.onTouchEvent(event); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); Paint paint = new Paint(); paint.setStyle(Paint.Style.STROKE); paint.setColor(Color.RED); paint.setStrokeWidth(2); canvas.drawPath(mPath,paint); } public void reset(){ mPath.reset(); postInvalidate(); } }

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。