Android实现图片随手指旋转功能

本文实例为大家分享了Android实现图片随手指旋转功能的具体代码，供大家参考，具体内容如下

在View中进行重绘，主要是通过计算角度及距离来实现。实现类代码如下：

package com.example.roatedemo; 

import java.util.Calendar;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View; 

public class RotateView extends View {
  private Paint mPaint = new Paint();
  private Bitmap bitmaplittele;//中间不动的图片
  private Bitmap bitmapBig;//随手指转动的图片
  private Bitmap bitmapOut;//外围不动的图片
  // 圆心坐标
  private float mPointX = 0, mPointY = 0; 

  private int flag = 0;
  // 半径
  private int mRadius = 0;
  // 旋转角度
  private int mAngle = 0;
  private int beginAngle = 0, currentAngle = 0;
  private String TAG = "NewView";
  int bitMap[] = { R.drawable.circle0, R.drawable.circle1, R.drawable.circle2 };
  int imageIndex = 0;
  boolean isUp = false,isTouch=false;
  Context mContext;
  RotateViewListener listener;
  long beginTime,endTime;
  Calendar now; 

  public RotateView(Context context, int px, int py, int radius,RotateViewListener listener) {
    super(context);
    mContext = context;
    this.listener = listener;
    mPointX = px;
    mPointY = py;
    mRadius = radius;
    bitmaplittele = BitmapFactory.decodeResource(getResources(),
        R.drawable.a1_pointer).copy(Bitmap.Config.ARGB_8888, true);
    bitmapBig = BitmapFactory.decodeResource(getResources(), bitMap[0])
        .copy(Bitmap.Config.ARGB_8888, true);
    bitmapOut = BitmapFactory.decodeResource(getResources(),
        R.drawable.bigcir).copy(Bitmap.Config.ARGB_8888, true);
    setBackgroundResource(R.drawable.back);
    Log.e(TAG, "RotateViewBegin");
  } 

  @Override
  public boolean dispatchTouchEvent(MotionEvent e) {
    switch (e.getAction() & MotionEvent.ACTION_MASK) {
    case MotionEvent.ACTION_DOWN:
      now = Calendar.getInstance();
      beginTime = now.getTimeInMillis();
      beginAngle = computeCurrentAngle(e.getX(), e.getY());
      isUp = false;
      //如果点击触摸范围在圈外，则不处理
      if (getDistance(e.getX(), e.getY())>bitmapOut.getWidth()/2) {
        isTouch=false;
      }else {
        isTouch=true;
      }
      return true;
    case MotionEvent.ACTION_MOVE:
      if (!isTouch) {
        return true;
      }
      currentAngle = computeCurrentAngle(e.getX(), e.getY());
      invalidate();
      return true;
    case MotionEvent.ACTION_UP:
      isUp = true;
      if (!isTouch) {
        return true;
      }
      now = Calendar.getInstance();
      endTime = now.getTimeInMillis();
      if (SetClick(e.getX(), e.getY())) {
        return true;
      }
      if (mAngle > 0) {
        int count = mAngle / 120 + (mAngle % 120 > 60 ? 1 : 0);
        imageIndex = (imageIndex + count) % 3;
      } else if (mAngle < 0) {
        mAngle = -mAngle;
        int count = mAngle / 120 + (mAngle % 120 > 60 ? 1 : 0);
        imageIndex = (imageIndex + 3 - count) % 3;
      }
      bitmapBig = BitmapFactory.decodeResource(getResources(),
          bitMap[imageIndex]).copy(Bitmap.Config.ARGB_8888, true);
      bitmapBig = adjustPhotoRotation(bitmapBig, imageIndex * 120);
      invalidate();
      if (mAngle >= 60) {
        listener.onModChange(imageIndex);
      }
      return true;
    } 

    return false;
  } 

  @Override
  public void onDraw(Canvas canvas) {
    // Log.i(TAG, "onDraw");
    // 大圆
    drawInCenter(canvas, bitmapOut, mPointX, mPointY, TAG);
    // 外圈
    if (isUp) {
      mAngle = 0;
    } else {
      mAngle = currentAngle - beginAngle;
    } 

    Bitmap tempBig = adjustPhotoRotation(bitmapBig, mAngle);
    // Log.i(TAG, "mAngle:"+mAngle);
    drawInCenter(canvas, tempBig, mPointX, mPointY + 10, TAG);
    // 小圆(中间的圆心)
    drawInCenter(canvas, bitmaplittele, mPointX, mPointY - 10, TAG);
  } 

  Bitmap adjustPhotoRotation(Bitmap bm, final int orientationDegree) {
    if (orientationDegree == 0) {
      return bm;
    }
    Matrix m = new Matrix();
    m.setRotate(orientationDegree, (float) bm.getWidth() / 2,
        (float) bm.getHeight() / 2); 

    try {
      Bitmap bm1 = Bitmap.createBitmap(bm, 0, 0, bm.getWidth(),
          bm.getHeight(), m, true); 

      return bm1; 

    } catch (OutOfMemoryError ex) {
    } 

    return null; 

  } 

  private void drawInCenter(Canvas canvas, Bitmap bitmap, float left,
      float top, String text) {
    canvas.drawBitmap(bitmap, left - bitmap.getWidth() / 2,
        top - bitmap.getHeight() / 2, null);
  } 

  // 子控件位置改变重新计算角度
  private int computeCurrentAngle(float x, float y) {
    // 根据圆心坐标计算角度
    float distance = (float) Math
        .sqrt(((x - mPointX) * (x - mPointX) + (y - mPointY)
            * (y - mPointY)));
    int degree = (int) (Math.acos((x - mPointX) / distance) * 180 / Math.PI);
    if (y < mPointY) {
      degree = -degree;
    }
    if (degree < 0) {
      degree += 360;
    } 

    // Log.i("RoundSpinView", "x:" + x + ",y:" + y + ",degree:" + degree);
    return degree;
  } 

  // 获取距离圆心的距离
  private float getDistance(float x, float y) {
    // 根据圆心坐标计算角度
    float distance = (float) Math
        .sqrt(((x - mPointX) * (x - mPointX) + (y - mPointY)
            * (y - mPointY)));
    return distance;
  } 

  //点击
  private boolean SetClick(float x, float y) {
    float distance = getDistance(x, y);
    if (mAngle>10||mAngle<-10) {
      return false;
    }else if(endTime-beginTime>1000){
      return false;
    }
    if (distance < bitmapBig.getWidth() / 2) {
      int mod = 0; 

      if (beginAngle < 90 || 330 < beginAngle) {
        mod = (imageIndex+3-1)%3;
      }
      else if (90 < beginAngle && 210 > beginAngle) {
        mod = (imageIndex+3-2)%3;
      }
      else{
        mod = imageIndex;
      }
      //回调到主界面进行处理。
      listener.onModClick(mod);
    }
    return true;
  } 

  public interface RotateViewListener {
    void onModClick(int mode);
    void onModChange(int mode);
  }
}

Activity中调用代码：

package com.example.roatedemo; 

import com.example.roatedemo.RotateView.RotateViewListener; 

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.util.Log;
import android.widget.Toast; 

public class MainActivity extends Activity implements RotateViewListener{ 

  RotateView rotateView;
  String TAG="MainActivity";
  Context mContext;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    mContext = this;
    int height,width;
    DisplayMetrics displayMetrics = new DisplayMetrics();
    getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
    height = displayMetrics.heightPixels;
    width = displayMetrics.widthPixels;
    Log.i(TAG, "height:"+height);
    Log.i(TAG, "width:"+width);
    rotateView = new RotateView(getApplicationContext(), width/2, height/3, 150,this); 

    setContentView(rotateView);
  }
  @Override
  public void onModClick(int mode) {
    String[] clickStrings = new String[] { "1被点击", "2被点击","3被点击" };
    Toast.makeText(mContext, clickStrings[mode], 0).show(); 

  }
  @Override
  public void onModChange(int mode) {
    String[] clickStrings = new String[] { "切换到1", "切换到2","切换到3" };
    Toast.makeText(mContext, clickStrings[mode], 0).show();
  } 

} 

布局文件默认即可。

除了实现图片旋转，还实现将图片切成3部分，每部分120度，每转动120度切换一个模式，点击每个部分均有响应事件回调到主界面。涉及保密，图片不给在此给出。

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我们。