【Android自定义View实战】之仿去哪儿网App图片按压显示指纹并缩放效果TouchFingerImageView

转载请注明出处：http://blog.csdn.net/linglongxin24/article/details/52986713 【DylanAndroid的csdn博客】

我们发现去哪儿网app的首页做的win8风格的方块，然后按压方块后悔发现，这个图片不但有缩放效果，而且还有显示指纹的效果，感觉跟真的手指按上去一样，很高逼格。今天我们就来看一下，这个是如何实现的。

1.先看一下效果图

2.第一步，准备一张指纹效果的透明背景图片

由于透明的看不到效果，我就连背景图片一起在这里显示了

3.第二步开始自定义View,有详细注释

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.drawable.BitmapDrawable;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.ScaleAnimation;
import android.widget.ImageView;

/** * 自定义仿去哪儿手指按下图片缩放和显示指纹的效果 * Created by yuandl on 2016-10-31. */

public class TouchFingerImageView extends ImageView {

    /** * 指纹的图片 */
    private Bitmap fingerBitmap;
    /** * 图片按下的状态标识 */
    private boolean state = false;
    /** * 点击事件 */
    private OnClickListener onClickListener;

    /** * 默认的构造函数 * * @param context * @param attrs */
    public TouchFingerImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
        /**获取指纹图片*/
        fingerBitmap = zoom(BitmapFactory.decodeResource(getResources(), R.mipmap.finger), 300, 300);

    }

    /** * 图片的缩放方法 * * @param bitmap 源图片资源 * @param newWidth 缩放后的宽 * @param newHeight 缩放后的高 * @return Bitmap 缩放后的图片资源 */
    public Bitmap zoom(Bitmap bitmap, int newWidth, int newHeight) {
        // 获取这个图片的宽和高
        float width = bitmap.getWidth();
        float height = bitmap.getHeight();
        // 计算宽高缩放率
        float rateWidth = ((float) newWidth) / width;
        float rateHeight = ((float) newHeight) / height;
        // 创建操作图片用的matrix对象
        Matrix matrix = new Matrix();
        // 缩放图片动作
        matrix.postScale(rateWidth, rateHeight);
        //创建一个新的缩放后的bitmap
        Bitmap zoomBitmap = Bitmap.createBitmap(bitmap, 0, 0, (int) width,
                (int) height, matrix, true);
        return zoomBitmap;
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        /**获取源资源图片文件**/
        Bitmap bitmap = ((BitmapDrawable) this.getDrawable()).getBitmap();
        Matrix matrix0 = new Matrix();
        /** * 平移指纹图片使指纹居中显示 */
        matrix0.postTranslate(this.getWidth() / 2 - fingerBitmap.getWidth() / 2,
                this.getHeight() / 2 - fingerBitmap.getHeight() / 2);
        /**绘制源资源图片文件**/
        canvas.drawBitmap(zoom(bitmap, getWidth(), getHeight()), 0, 0, null);
        if (state) {
            Matrix matrix = new Matrix();
            /** * 平移指纹图片使指纹居中显示 */
            matrix.postTranslate(this.getWidth() / 2 - fingerBitmap.getWidth() / 2,
                    this.getHeight() / 2 - fingerBitmap.getHeight() / 2);
            canvas.drawBitmap(fingerBitmap, matrix, null);
        }
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        float begin = 1.0f;
        float end = 0.95f;
        /** 收缩动画**/
        Animation beginAnimation = new ScaleAnimation(begin, end, begin, end,
                Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF,
                0.5f);
        /** 伸展动画**/
        Animation finishAnimation = new ScaleAnimation(end, begin, end, begin,
                Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF,
                0.5f);

        /** 设置动画持续时间和保留动画结果 **/
        beginAnimation.setDuration(200);
        /**设置动画停留在最后一个的状态**/
        beginAnimation.setFillAfter(true);
        finishAnimation.setDuration(200);
        finishAnimation.setFillAfter(true);

        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN://手指按下时
                startAnimation(beginAnimation);
                state = true;
                invalidate();
                if (onClickListener != null) {
                    onClickListener.onClick(this);
                }
                break;
            case MotionEvent.ACTION_UP:
                startAnimation(finishAnimation);
                state = false;
                invalidate();
                break;
            case MotionEvent.ACTION_CANCEL:
                startAnimation(finishAnimation);
                state = false;
                invalidate();
                break;
        }
        return true;
    }

    @Override
    public void setOnClickListener(OnClickListener onClickListener) {
        this.onClickListener = onClickListener;
    }
}

4.用法

• 布局文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main" android:layout_width="match_parent" android:layout_height="match_parent" android:background="#393939" android:orientation="vertical" tools:context="cn.bluemobi.dylan.touchfingerimageview.MainActivity">

    <LinearLayout  android:layout_width="match_parent" android:layout_height="120dp" android:layout_marginTop="10dp" android:orientation="horizontal">

        <cn.bluemobi.dylan.touchfingerimageview.TouchFingerImageView  android:id="@+id/tfiv1" android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1.00" android:scaleType="centerCrop" android:src="@mipmap/iv1" />

        <cn.bluemobi.dylan.touchfingerimageview.TouchFingerImageView  android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginLeft="10dp" android:layout_weight="2.00" android:scaleType="centerCrop" android:src="@mipmap/iv2" />
    </LinearLayout>

    <LinearLayout  android:layout_width="match_parent" android:layout_height="120dp" android:layout_marginTop="10dp" android:orientation="horizontal">

        <cn.bluemobi.dylan.touchfingerimageview.TouchFingerImageView  android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1.00" android:scaleType="centerCrop" android:src="@mipmap/iv3" />

        <cn.bluemobi.dylan.touchfingerimageview.TouchFingerImageView  android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginLeft="10dp" android:layout_weight="1.00" android:scaleType="centerCrop" android:src="@mipmap/iv4" />

        <cn.bluemobi.dylan.touchfingerimageview.TouchFingerImageView  android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginLeft="10dp" android:layout_weight="1.00" android:scaleType="centerCrop" android:src="@mipmap/iv5" />

    </LinearLayout>

    <LinearLayout  android:layout_width="match_parent" android:layout_height="120dp" android:layout_marginTop="10dp" android:orientation="horizontal">

        <cn.bluemobi.dylan.touchfingerimageview.TouchFingerImageView  android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1.00" android:scaleType="centerCrop" android:src="@mipmap/iv6" />

        <cn.bluemobi.dylan.touchfingerimageview.TouchFingerImageView  android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginLeft="10dp" android:layout_weight="1.00" android:scaleType="centerCrop" android:src="@mipmap/iv7" />

        <cn.bluemobi.dylan.touchfingerimageview.TouchFingerImageView  android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginLeft="10dp" android:layout_weight="1.00" android:scaleType="centerCrop" android:src="@mipmap/iv8" />

    </LinearLayout>

    <LinearLayout  android:layout_width="match_parent" android:layout_height="120dp" android:layout_marginTop="10dp" android:orientation="horizontal">

        <cn.bluemobi.dylan.touchfingerimageview.TouchFingerImageView  android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1.00" android:scaleType="centerCrop" android:src="@mipmap/iv9" />

        <cn.bluemobi.dylan.touchfingerimageview.TouchFingerImageView  android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginLeft="10dp" android:layout_weight="1.00" android:scaleType="centerCrop" android:src="@mipmap/iv10" />

        <cn.bluemobi.dylan.touchfingerimageview.TouchFingerImageView  android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginLeft="10dp" android:layout_weight="1.00" android:scaleType="centerCrop" android:src="@mipmap/iv11" />

    </LinearLayout>
</LinearLayout>

• Activity中的用法

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.tfiv1).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(MainActivity.this,"点击了第一个",Toast.LENGTH_SHORT).show();
            }
        });
    }
}

5.GitHub源码：https://github.com/linglongxin24/TouchFingerImageView