Android中怎么实现多点触摸

Android中怎么实现多点触摸，针对这个问题，这篇文章详细介绍了相对应的分析和解答，希望可以帮助更多想解决这个问题的小伙伴找到更简单易行的方法。

首先来看看我们的视图类MTView.java:

package com.ideasandroid.demo;     import android.content.Context;  import android.graphics.Canvas;  import android.graphics.Color;  import android.graphics.Paint;  import android.view.MotionEvent;  import android.view.SurfaceHolder;  import android.view.SurfaceView;     public class MTView extends SurfaceView implements SurfaceHolder.Callback {         private static final int MAX_TOUCHPOINTS = 10;      private static final String START_TEXT = "请随便触摸屏幕进行测试";      private Paint textPaint = new Paint();      private Paint touchPaints[] = new Paint[MAX_TOUCHPOINTS];      private int colors[] = new int[MAX_TOUCHPOINTS];         private int width, height;      private float scale = 1.0f;         public MTView(Context context) {          super(context);          SurfaceHolder holder = getHolder();          holder.addCallback(this);          setFocusable(true); // 确保我们的View能获得输入焦点          setFocusableInTouchMode(true); // 确保能接收到触屏事件          init();      }         private void init() {          // 初始化10个不同颜色的画笔          textPaint.setColor(Color.WHITE);          colors[0] = Color.BLUE;          colors[1] = Color.RED;          colors[2] = Color.GREEN;          colors[3] = Color.YELLOW;          colors[4] = Color.CYAN;          colors[5] = Color.MAGENTA;          colors[6] = Color.DKGRAY;          colors[7] = Color.WHITE;          colors[8] = Color.LTGRAY;          colors[9] = Color.GRAY;          for (int i = 0; i < MAX_TOUCHPOINTS; i++) {              touchPaints[i] = new Paint();              touchPaints[i].setColor(colors[i]);          }      }         /*       * 处理触屏事件       */      @Override      public boolean onTouchEvent(MotionEvent event) {          // 获得屏幕触点数量          int pointerCount = event.getPointerCount();          if (pointerCount > MAX_TOUCHPOINTS) {              pointerCount = MAX_TOUCHPOINTS;          }          // 锁定Canvas,开始进行相应的界面处理          Canvas c = getHolder().lockCanvas();          if (c != null) {              c.drawColor(Color.BLACK);              if (event.getAction() == MotionEvent.ACTION_UP) {                  // 当手离开屏幕时，清屏              } else {                  // 先在屏幕上画一个十字，然后画一个圆                  for (int i = 0; i < pointerCount; i++) {                      // 获取一个触点的坐标，然后开始绘制                      int id = event.getPointerId(i);                      int x = (int) event.getX(i);                      int y = (int) event.getY(i);                      drawCrosshairsAndText(x, y, touchPaints[id], i, id, c);                  }                  for (int i = 0; i < pointerCount; i++) {                      int id = event.getPointerId(i);                      int x = (int) event.getX(i);                      int y = (int) event.getY(i);                      drawCircle(x, y, touchPaints[id], c);                  }              }              // 画完后，unlock              getHolder().unlockCanvasAndPost(c);          }          return true;      }         /**       * 画十字及坐标信息       *       * @param x       * @param y       * @param paint       * @param ptr       * @param id       * @param c       */      private void drawCrosshairsAndText(int x, int y, Paint paint, int ptr,              int id, Canvas c) {          c.drawLine(0, y, width, y, paint);          c.drawLine(x, 0, x, height, paint);          int textY = (int) ((15 + 20 * ptr) * scale);          c.drawText("x" + ptr + "=" + x, 10 * scale, textY, textPaint);          c.drawText("y" + ptr + "=" + y, 70 * scale, textY, textPaint);          c.drawText("id" + ptr + "=" + id, width - 55 * scale, textY, textPaint);      }         /**       * 画圆       *       * @param x       * @param y       * @param paint       * @param c       */      private void drawCircle(int x, int y, Paint paint, Canvas c) {          c.drawCircle(x, y, 40 * scale, paint);      }         /*       * 进入程序时背景画成黑色，然后把“START_TEXT”写到屏幕       */      public void surfaceChanged(SurfaceHolder holder, int format, intwidth,              int height) {          this.width = width;          this.height = height;          if (width > height) {              this.scale = width / 480f;          } else {              this.scale = height / 480f;          }          textPaint.setTextSize(14 * scale);          Canvas c = getHolder().lockCanvas();          if (c != null) {              // 背景黑色              c.drawColor(Color.BLACK);              float tWidth = textPaint.measureText(START_TEXT);              c.drawText(START_TEXT, width / 2 - tWidth / 2, height / 2,                      textPaint);              getHolder().unlockCanvasAndPost(c);          }      }         public void surfaceCreated(SurfaceHolder holder) {      }         public void surfaceDestroyed(SurfaceHolder holder) {      }     }

接下来看看我们的Activity，MultitouchVisible.java

package com.ideasandroid.demo;     import android.app.Activity;  import android.os.Bundle;  import android.view.Window;  import android.view.WindowManager;     public class MultitouchVisible extends Activity {      @Override      public void onCreate(Bundle savedInstanceState) {          super.onCreate(savedInstanceState);          //隐藏标题栏          requestWindowFeature(Window.FEATURE_NO_TITLE);          //设置成全屏          getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,                  WindowManager.LayoutParams.FLAG_FULLSCREEN);          //设置为上面的MTView          setContentView(new MTView(this));      }  }

关于Android中怎么实现多点触摸问题的解答就分享到这里了，希望以上内容可以对大家有一定的帮助，如果你还有很多疑惑没有解开，可以关注亿速云行业资讯频道了解更多相关知识。