Android中怎么實現多點觸摸

Android中怎么實現多點觸摸，針對這個問題，這篇文章詳細介紹了相對應的分析和解答，希望可以幫助更多想解決這個問題的小伙伴找到更簡單易行的方法。

首先來看看我們的視圖類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 = "請隨便觸摸屏幕進行測試";      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); // 確保我們的View能獲得輸入焦點          setFocusableInTouchMode(true); // 確保能接收到觸屏事件          init();      }         private void init() {          // 初始化10個不同顏色的畫筆          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]);          }      }         /*       * 處理觸屏事件       */      @Override      public boolean onTouchEvent(MotionEvent event) {          // 獲得屏幕觸點數量          int pointerCount = event.getPointerCount();          if (pointerCount > MAX_TOUCHPOINTS) {              pointerCount = MAX_TOUCHPOINTS;          }          // 鎖定Canvas,開始進行相應的界面處理          Canvas c = getHolder().lockCanvas();          if (c != null) {              c.drawColor(Color.BLACK);              if (event.getAction() == MotionEvent.ACTION_UP) {                  // 當手離開屏幕時，清屏              } else {                  // 先在屏幕上畫一個十字，然后畫一個圓                  for (int i = 0; i < pointerCount; i++) {                      // 獲取一個觸點的坐標，然后開始繪制                      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);                  }              }              // 畫完后，unlock              getHolder().unlockCanvasAndPost(c);          }          return true;      }         /**       * 畫十字及坐標信息       *       * @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);      }         /**       * 畫圓       *       * @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);      }         /*       * 進入程序時背景畫成黑色，然后把“START_TEXT”寫到屏幕       */      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) {      }     }

接下來看看我們的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);          //隱藏標題欄          requestWindowFeature(Window.FEATURE_NO_TITLE);          //設置成全屏          getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,                  WindowManager.LayoutParams.FLAG_FULLSCREEN);          //設置為上面的MTView          setContentView(new MTView(this));      }  }

關于Android中怎么實現多點觸摸問題的解答就分享到這里了，希望以上內容可以對大家有一定的幫助，如果你還有很多疑惑沒有解開，可以關注億速云行業資訊頻道了解更多相關知識。