android 圖片的平移,縮放和旋轉，

android 圖片的平移,縮放和旋轉，

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="horizontal" >    <!-- 定義TextView的文字標籤 -->    <TextView        android:id="@+id/Tv"        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:text="點擊螢幕，隱藏或顯示導覽列！" /></RelativeLayout>

MyView.java

package com.example.yanlei.yl;import android.app.Activity;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Canvas;import android.graphics.Matrix;import android.graphics.PointF;import android.util.DisplayMetrics;import android.util.FloatMath;import android.view.MotionEvent;import android.widget.ImageView;//自訂MyView類繼承自ImageViewpublic class MyView extends ImageView {    private float x_down = 0;    private float y_down = 0;    //起始點的座標    private PointF start = new PointF();    //中心點的座標    private PointF mid = new PointF();    private float oldDist = 1f;    private float oldRotation = 0;    private Matrix matrix = new Matrix();    private Matrix matrix1 = new Matrix();    private Matrix savedMatrix = new Matrix();    private static final int NONE = 0;    private static final int DRAG = 1;    private static final int ZOOM = 2;    private int mode = NONE;    private boolean matrixCheck = false;    //記錄當前螢幕的寬度    private int widthScreen;    //記錄當前螢幕的高度    private int heightScreen;    //在頁面中顯示的Bitmap圖片    private Bitmap kenan;    public MyView(Activity activity) {        super(activity);        //通過Bitampfactory讀取drawable目錄下的kenan資源        kenan = BitmapFactory.                decodeResource(getResources(), R.drawable.kenan);        //定義圖片一個顯示矩陣        DisplayMetrics dm = new DisplayMetrics();        //得到當前螢幕的顯示矩陣存入dm變數        activity.getWindowManager().                getDefaultDisplay().getMetrics(dm);        //通過顯示矩陣得到當前螢幕的寬度和高度的像素值        widthScreen = dm.widthPixels;        heightScreen = dm.heightPixels;        matrix = new Matrix();    }    //顯示view的時候回調onDraw    protected void onDraw(Canvas canvas) {        //首先儲存當前頁面已有的映像        canvas.save();        //按照當前的矩陣繪製kenan圖片        canvas.drawBitmap(kenan, matrix, null);        //畫圖板恢複        canvas.restore();    }    //當使用者觸摸此視圖的時候回調次方法    public boolean onTouchEvent(MotionEvent event) {        //得到touch的事件類型        switch (event.getAction() & MotionEvent.ACTION_MASK) {            case MotionEvent.ACTION_DOWN:                //當按下螢幕時，記錄當前的狀態為拖動                mode = DRAG;                //記錄xy座標                x_down = event.getX();                y_down = event.getY();                //儲存當前的矩陣                savedMatrix.set(matrix);                break;            case MotionEvent.ACTION_POINTER_DOWN:                //多個手指觸摸的狀態                mode = ZOOM;                //記錄之前的兩手指間距                oldDist = spacing(event);                //記錄之前的角度                oldRotation = rotation(event);                //儲存當前的圖片矩陣                savedMatrix.set(matrix);                //得到旋轉的中心點                midPoint(mid, event);                break;            case MotionEvent.ACTION_MOVE:                //當手指移動時的狀態                if (mode == ZOOM) {                    //縮放並且平移                    matrix1.set(savedMatrix);                    //得到旋轉的角度                    float rotation =                            rotation(event) - oldRotation;                    //得到距離                    float newDist = spacing(event);                    //得到放大倍數                    float scale = newDist / oldDist;                    //縮放倍數                    matrix1.postScale(scale, scale, mid.x, mid.y);                    //得到旋轉角度                    matrix1.postRotate(rotation, mid.x, mid.y);                    //得到圖片是否出邊界                    matrixCheck = matrixCheck();                    if (matrixCheck == false) {                        matrix.set(matrix1);                        invalidate();                    }                } else if (mode == DRAG) {                    //平行移動                    matrix1.set(savedMatrix);                    matrix1.postTranslate(event.getX() - x_down                            , event.getY() - y_down);// 平移                    matrixCheck = matrixCheck();                    matrixCheck = matrixCheck();                    if (matrixCheck == false) {                        matrix.set(matrix1);                        invalidate();                    }                }                break;            case MotionEvent.ACTION_UP:            case MotionEvent.ACTION_POINTER_UP:                mode = NONE;                break;        }        return true;    }    //對圖片的矩陣進行檢測    private boolean matrixCheck() {        float[] f = new float[9];        matrix1.getValues(f);        // 圖片4個頂點的座標        float x1 = f[0] * 0 + f[1] * 0 + f[2];        float y1 = f[3] * 0 + f[4] * 0 + f[5];        float x2 = f[0] * kenan.getWidth()                + f[1] * 0 + f[2];        float y2 = f[3] * kenan.getWidth()                + f[4] * 0 + f[5];        float x3 = f[0] * 0 + f[1] *                kenan.getHeight() + f[2];        float y3 = f[3] * 0 + f[4] *                kenan.getHeight() + f[5];        float x4 = f[0] * kenan.getWidth() +                f[1] * kenan.getHeight() + f[2];        float y4 = f[3] * kenan.getWidth() +                f[4] * kenan.getHeight() + f[5];        // 圖片現寬度        double width = Math.sqrt((x1 - x2) *                (x1 - x2) + (y1 - y2) * (y1 - y2));        // 縮放比率判斷        if (width < widthScreen / 3 || width > widthScreen * 3) {            return true;        }        // 出界判斷        if ((x1 < widthScreen / 3 && x2 < widthScreen / 3                && x3 < widthScreen / 3                && x4 < widthScreen / 3)                || (x1 > widthScreen * 2 / 3                && x2 > widthScreen * 2 / 3                && x3 > widthScreen * 2 / 3                && x4 > widthScreen * 2 / 3)                || (y1 < heightScreen / 3                && y2 < heightScreen / 3                && y3 < heightScreen / 3                && y4 < heightScreen / 3)                || (y1 > heightScreen * 2 / 3                && y2 > heightScreen * 2 / 3                && y3 > heightScreen * 2 / 3                && y4 > heightScreen * 2 / 3)) {            return true;        }        return false;    }    // 觸碰兩點間距離    private float spacing(MotionEvent event) {        //通過三角函數得到兩點間的距離        float x = event.getX(0) - event.getX(1);        float y = event.getY(0) - event.getY(1);        return FloatMath.sqrt(x * x + y * y);    }    // 取手勢中心點    private void midPoint(PointF point, MotionEvent event) {        //得到手勢中心點的位置        float x = event.getX(0) + event.getX(1);        float y = event.getY(0) + event.getY(1);        point.set(x / 2, y / 2);    }    // 取旋轉角度    private float rotation(MotionEvent event) {        //得到兩個手指間的旋轉角度        double delta_x = (event.getX(0) - event.getX(1));        double delta_y = (event.getY(0) - event.getY(1));        double radians = Math.atan2(delta_y, delta_x);        return (float) Math.toDegrees(radians);    }}

 

MainActivity

package com.example.yanlei.yl;import android.graphics.Color;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.Menu;import android.view.MenuItem;import android.widget.TextView;import android.text.Html;import android.text.Html.ImageGetter;import java.util.regex.Matcher;import java.util.regex.Pattern;import android.text.Editable;import android.text.TextWatcher;import android.widget.EditText;import android.widget.Button;import android.app.Activity;import android.content.Intent;import android.view.MotionEvent;import android.widget.TextView;import android.view.Window;import android.view.WindowManager;public class MainActivity extends AppCompatActivity {    //定義TextView對象    private TextView Tv;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        //定義自訂View的對象        MyView myview = new MyView(this);        //設定當前頁面的視圖為自訂的myview        setContentView(myview);    }}