自定義實現雙擊放大縮小的ImageView控件

一、創建一個名爲 ZoomImageView的類，裏面寫有支持圖片放大縮小的功能

package cgg.com.threeapp.view.costomView;

import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Matrix;
import android.graphics.RectF;
import android.graphics.drawable.Drawable;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewTreeObserver;
import android.widget.ImageView;

/**
 * author: Wanderer
 * date:   2018/3/21 20:49
 * email:  none
 */

@SuppressLint("AppCompatCustomView")
public class ZoomImageView extends ImageView implements ViewTreeObserver.OnGlobalLayoutListener, ScaleGestureDetector.OnScaleGestureListener, View.OnTouchListener {
private boolean mOnce;

/**
 * 初始化時縮放的值
 */
private float mInitScale;

/**
 * 雙擊放大值到達的值
 */
private float mMidScale;

/**
 * 放大的最大值
 */
private float mMaxScale;

private Matrix mScaleMatrix;

/**
 * 捕獲用戶多指觸控時縮放的比例
 */
private ScaleGestureDetector mScaleGestureDetector;

// **********自由移動的變量***********
/**
 * 記錄上一次多點觸控的數量
 */
private int mLastPointerCount;

private float mLastX;
private float mLastY;

private int mTouchSlop;
private boolean isCanDrag;

private boolean isCheckLeftAndRight;
private boolean isCheckTopAndBottom;

// *********雙擊放大與縮小*********
private GestureDetector mGestureDetector;

private boolean isAutoScale;

public ZoomImageView(Context context) {
        this(context, null);
        }

public ZoomImageView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
        }


public ZoomImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        // init
        mScaleMatrix = new Matrix();
        setScaleType(ScaleType.MATRIX);
        setOnTouchListener(this);
        mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
        mScaleGestureDetector = new ScaleGestureDetector(context, this);
        mGestureDetector = new GestureDetector(context,
        new GestureDetector.SimpleOnGestureListener() {
@Override
public boolean onDoubleTap(MotionEvent e) {

        if (isAutoScale) {
        return true;
        }

        float x = e.getX();
        float y = e.getY();

        if (getScale() < mMidScale) {
        postDelayed(new AutoScaleRunnable(mMidScale, x, y), 16);
        isAutoScale = true;
        } else {
        postDelayed(new AutoScaleRunnable(mInitScale, x, y), 16);
        isAutoScale = true;
        }
        return true;
        }
        });
        }

/**
 * 自動放大與縮小
 *
 * @author [email protected]
 *
 */
private class AutoScaleRunnable implements Runnable {
    /**
     * 縮放的目標值
     */
    private float mTargetScale;
    // 縮放的中心點
    private float x;
    private float y;

    private final float BIGGER = 1.07f;
    private final float SMALL = 0.93f;

    private float tmpScale;

    /**
     * @param mTargetScale
     * @param x
     * @param y
     */
    public AutoScaleRunnable(float mTargetScale, float x, float y) {
        this.mTargetScale = mTargetScale;
        this.x = x;
        this.y = y;

        if (getScale() < mTargetScale) {
            tmpScale = BIGGER;
        }
        if (getScale() > mTargetScale) {
            tmpScale = SMALL;
        }
    }

    @Override
    public void run() {
        //進行縮放
        mScaleMatrix.postScale(tmpScale, tmpScale, x, y);
        checkBorderAndCenterWhenScale();
        setImageMatrix(mScaleMatrix);

        float currentScale = getScale();

        if ((tmpScale >1.0f && currentScale <mTargetScale) ||(tmpScale<1.0f &&currentScale>mTargetScale)) {
            //這個方法是重新調用run()方法
            postDelayed(this, 16);
        }else{
            //設置爲我們的目標值
            float scale = mTargetScale/currentScale;
            mScaleMatrix.postScale(scale, scale, x, y);
            checkBorderAndCenterWhenScale();
            setImageMatrix(mScaleMatrix);

            isAutoScale = false;
        }
    }
}

    /**
     * 獲取ImageView加載完成的圖片
     */
    @Override
    public void onGlobalLayout() {
        if (!mOnce) {
            // 得到控件的寬和高
            int width = getWidth();
            int height = getHeight();

            // 得到我們的圖片，以及寬和高
            Drawable drawable = getDrawable();
            if (drawable == null) {
                return;
            }
            int dh = drawable.getIntrinsicHeight();
            int dw = drawable.getIntrinsicWidth();

            float scale = 0.6f;

            // 圖片的寬度大於控件的寬度，圖片的高度小於空間的高度，我們將其縮小
            if (dw > width && dh < height) {
                scale = width * 1.0f / dw;
            }

            // 圖片的寬度小於控件的寬度，圖片的高度大於空間的高度，我們將其縮小
            if (dh > height && dw < width) {
                scale = height * 1.0f / dh;
            }

            // 縮小值
            if (dw > width && dh > height) {
                scale = Math.min(width * 1.0f / dw, height * 1.0f / dh);
            }

            // 放大值
            if (dw < width && dh < height) {
                scale = Math.min(width * 1.0f / dw, height * 1.0f / dh);
            }

            /**
             * 得到了初始化時縮放的比例
             */
            mInitScale = scale;
            mMaxScale = mInitScale * 4;
            mMidScale = mInitScale * 2;

            // 將圖片移動至控件的中間
            int dx = getWidth() / 2 - dw / 2;
            int dy = getHeight() / 2 - dh / 2;

            mScaleMatrix.postTranslate(dx, dy);
            mScaleMatrix.postScale(mInitScale, mInitScale, width / 2,
                    height / 2);
            setImageMatrix(mScaleMatrix);

            mOnce = true;
        }
    }

    /**
     * 註冊OnGlobalLayoutListener這個接口
     */
    @Override
    protected void onAttachedToWindow() {
        super.onAttachedToWindow();
        getViewTreeObserver().addOnGlobalLayoutListener(this);
    }

    /**
     * 取消OnGlobalLayoutListener這個接口
     */
    @SuppressWarnings("deprecation")
    @Override
    protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();
        getViewTreeObserver().removeGlobalOnLayoutListener(this);
    }

    /**
     * 獲取當前圖片的縮放值
     *
     * @return
     */
    public float getScale() {
        float[] values = new float[9];
        mScaleMatrix.getValues(values);
        return values[Matrix.MSCALE_X];
    }

    // 縮放區間時initScale maxScale
    @Override
    public boolean onScale(ScaleGestureDetector detector) {
        float scale = getScale();
        float scaleFactor = detector.getScaleFactor();

        if (getDrawable() == null) {
            return true;
        }

        // 縮放範圍的控制
        if ((scale < mMaxScale && scaleFactor > 1.0f)
                || (scale > mInitScale && scaleFactor < 1.0f)) {
            if (scale * scaleFactor < mInitScale) {
                scaleFactor = mInitScale / scale;
            }

            if (scale * scaleFactor > mMaxScale) {
                scale = mMaxScale / scale;
            }

            // 縮放
            mScaleMatrix.postScale(scaleFactor, scaleFactor,
                    detector.getFocusX(), detector.getFocusY());

            checkBorderAndCenterWhenScale();

            setImageMatrix(mScaleMatrix);
        }

        return true;
    }

    /**
     * 獲得圖片放大縮小以後的寬和高，以及left，right，top，bottom
     *
     * @return
     */
    private RectF getMatrixRectF() {
        Matrix matrix = mScaleMatrix;
        RectF rectF = new RectF();
        Drawable d = getDrawable();
        if (d != null) {
            rectF.set(0, 0, d.getIntrinsicWidth(), d.getIntrinsicHeight());
            matrix.mapRect(rectF);
        }
        return rectF;
    }

    /**
     * 在縮放的時候進行邊界以及我們的位置的控制
     */
    private void checkBorderAndCenterWhenScale() {
        RectF rectF = getMatrixRectF();
        float deltaX = 0;
        float deltaY = 0;

        int width = getWidth();
        int height = getHeight();

        // 縮放時進行邊界檢測，防止出現白邊
        if (rectF.width() >= width) {
            if (rectF.left > 0) {
                deltaX = -rectF.left;
            }
            if (rectF.right < width) {
                deltaX = width - rectF.right;
            }
        }

        if (rectF.height() >= height) {
            if (rectF.top > 0) {
                deltaY = -rectF.top;
            }
            if (rectF.bottom < height) {
                deltaY = height - rectF.bottom;
            }
        }

        /**
         * 如果寬度或高度小於空間的寬或者高，則讓其居中
         */
        if (rectF.width() < width) {
            deltaX = width / 2f - rectF.right + rectF.width() / 2f;
        }

        if (rectF.height() < height) {
            deltaY = height / 2f - rectF.bottom + rectF.height() / 2f;
        }

        mScaleMatrix.postTranslate(deltaX, deltaY);
    }

    @Override
    public boolean onScaleBegin(ScaleGestureDetector detector) {

        return true;
    }

    @Override
    public void onScaleEnd(ScaleGestureDetector detector) {

    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {

        if (mGestureDetector.onTouchEvent(event)) {
            return true;
        }

        mScaleGestureDetector.onTouchEvent(event);

        float x = 0;
        float y = 0;
        // 拿到多點觸控的數量
        int pointerCount = event.getPointerCount();
        for (int i = 0; i < pointerCount; i++) {
            x += event.getX(i);
            y += event.getY(i);
        }

        x /= pointerCount;
        y /= pointerCount;

        if (mLastPointerCount != pointerCount) {
            isCanDrag = false;
            mLastX = x;
            mLastY = y;
        }
        mLastPointerCount = pointerCount;
        RectF rectF = getMatrixRectF();
        switch (event.getAction()) {

            case MotionEvent.ACTION_DOWN:
                if (rectF.width()>getWidth() +0.01|| rectF.height()>getHeight()+0.01) {
                    if(getParent() instanceof ViewPager)
                        getParent().requestDisallowInterceptTouchEvent(true);
                }
                break;

            case MotionEvent.ACTION_MOVE:
                if (rectF.width()>getWidth()+0.01 || rectF.height()>getHeight()+0.01) {
                    if(getParent() instanceof ViewPager)
                        getParent().requestDisallowInterceptTouchEvent(true);
                }
                float dx = x - mLastX;
                float dy = y - mLastY;

                if (!isCanDrag) {
                    isCanDrag = isMoveAction(dx, dy);
                }

                if (isCanDrag) {
                    if (getDrawable() != null) {
                        isCheckLeftAndRight = isCheckTopAndBottom = true;
                        // 如果寬度小於控件寬度，不允許橫向移動
                        if (rectF.width() < getWidth()) {
                            isCheckLeftAndRight = false;
                            dx = 0;
                        }
                        // 如果高度小於控件高度，不允許縱向移動
                        if (rectF.height() < getHeight()) {
                            isCheckTopAndBottom = false;
                            dy = 0;
                        }
                        mScaleMatrix.postTranslate(dx, dy);

                        checkBorderWhenTranslate();

                        setImageMatrix(mScaleMatrix);
                    }
                }
                mLastX = x;
                mLastY = y;
                break;
            case MotionEvent.ACTION_UP:
            case MotionEvent.ACTION_CANCEL:
                mLastPointerCount = 0;
                break;

            default:
                break;
        }

        return true;
    }

    /**
     * 當移動時進行邊界檢查
     */
    private void checkBorderWhenTranslate() {
        RectF rectF = getMatrixRectF();
        float deltaX = 0;
        float deltaY = 0;

        int width = getWidth();
        int heigth = getHeight();

        if (rectF.top > 0 && isCheckTopAndBottom) {
            deltaY = -rectF.top;
        }
        if (rectF.bottom < heigth && isCheckTopAndBottom) {
            deltaY = heigth - rectF.bottom;
        }
        if (rectF.left > 0 && isCheckLeftAndRight) {
            deltaX = -rectF.left;
        }
        if (rectF.right < width && isCheckLeftAndRight) {
            deltaX = width - rectF.right;
        }
        mScaleMatrix.postTranslate(deltaX, deltaY);

    }

    /**
     * 判斷是否是move
     *
     * @param dx
     * @param dy
     * @return
     */
    private boolean isMoveAction(float dx, float dy) {
        return Math.sqrt(dx * dx + dy * dy) > mTouchSlop;
    }

}

二、在佈局中進行引用創建的那個類

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.xwj.lenovo.xuwenjuan20180505.view.PhotoIconActivity">

    <com.xwj.lenovo.xuwenjuan20180505.application.ZoomImageView
        android:id="@+id/po"
        android:src="@mipmap/ic_launcher"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
</LinearLayout>

三、adpter傳遞過來的圖片路徑

  holder.icon.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(context, PhotoIconActivity.class);
                intent.putExtra("icon",list.get(position).getUrl());
                context.startActivity(intent);
            }
        });

四、在Activity中調用

package com.xwj.lenovo.xuwenjuan20180505.view;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;

import com.bumptech.glide.Glide;
import com.xwj.lenovo.xuwenjuan20180505.R;
import com.xwj.lenovo.xuwenjuan20180505.application.ZoomImageView;
import butterknife.BindView;
import butterknife.ButterKnife;

public class PhotoIconActivity extends AppCompatActivity {


    @BindView(R.id.po)
    ZoomImageView po;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_photo_icon);
        ButterKnife.bind(this);
        //獲取adapter傳過來的圖片路徑
        String icon = getIntent().getStringExtra("icon");
        //判斷圖片不爲空
        if (icon != null) {
            Glide.with(this).load(icon).into(po);
        }
    }
}

自定義實現雙擊放大縮小的ImageView控件

AngularJS網絡請求數據、刪除、查找、排序

AngularJs表格增加、刪除、關鍵字查詢、按數量排序

Angular 模擬簡單購物車

表單的地址聯動添加~刪除

AngularJS增、刪、改、查

https://yachay.unat.edu.pe/blog/index.php?comment_area=format_blog&comment_component=blog&comment_co

linux以太網驅動總結