Android实现点击缩略图放大效果

本文实例为大家分享了android点击缩略图放大效果的具体代码，供大家参考，具体内容如下

import android.animation.animator;
import android.animation.animatorlisteneradapter;
import android.animation.animatorset;
import android.animation.objectanimator;
import android.graphics.point;
import android.graphics.rect;
import android.os.bundle;
import android.support.v7.app.appcompatactivity;
import android.view.view;
import android.view.animation.decelerateinterpolator;
import android.widget.imageview;

public class mainactivity extends appcompatactivity {

  // 持有这个动画的引用，让他可以在动画执行中途取消
  private animator mcurrentanimator;

  private int mshortanimationduration;

  private view imageview1;
  private view imageview2;

  @override
  protected void oncreate(bundle savedinstancestate) {
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.activity_main);
    initview();

    imageview1.setonclicklistener(new view.onclicklistener() {
      @override
      public void onclick(view v) {
        zoomimagefromthumb(imageview1,r.mipmap.ic_launcher);
      }
    });
    imageview2.setonclicklistener(new view.onclicklistener() {
      @override
      public void onclick(view v) {
        zoomimagefromthumb(imageview2,r.mipmap.ic_launcher);
      }
    });

    // 系统默认的短动画执行时间 200
    mshortanimationduration = getresources().getinteger(
        android.r.integer.config_shortanimtime);
  }

  private void initview() {
    imageview1 = (imageview) findviewbyid(r.id.imageview1);
    imageview2 = (imageview) findviewbyid(r.id.imageview2);
  }
  private void zoomimagefromthumb(final view thumbview, int imageresid) {
    // 如果有动画正在运行，取消这个动画
    if (mcurrentanimator != null) {
      mcurrentanimator.cancel();
    }

    // 加载显示大图的imageview
    final imageview expandedimageview = (imageview) findviewbyid(
        r.id.expanded_image);
    expandedimageview.setimageresource(imageresid);

    // 计算初始小图的边界位置和最终大图的边界位置。
    final rect startbounds = new rect();
    final rect finalbounds = new rect();
    final point globaloffset = new point();

    // 小图的边界就是小imageview的边界，大图的边界因为是铺满全屏的，所以就是整个布局的边界。
    // 然后根据偏移量得到正确的坐标。
    thumbview.getglobalvisiblerect(startbounds);
    findviewbyid(r.id.imageview1).getglobalvisiblerect(finalbounds, globaloffset);
    startbounds.offset(-globaloffset.x, -globaloffset.y);
    finalbounds.offset(-globaloffset.x, -globaloffset.y);

    // 计算初始的缩放比例。最终的缩放比例为1。并调整缩放方向，使看着协调。
    float startscale=0;
    if ((float) finalbounds.width() / finalbounds.height()
        > (float) startbounds.width() / startbounds.height()) {
      // 横向缩放
      float startwidth = startscale * finalbounds.width();
      float deltawidth = (startwidth - startbounds.width()) / 2;
      startbounds.left -= deltawidth;
      startbounds.right += deltawidth;
    } else {
      // 竖向缩放
      float startheight = startscale * finalbounds.height();
      float deltaheight = (startheight - startbounds.height()) / 2;
      startbounds.top -= deltaheight;
      startbounds.bottom += deltaheight;
    }

    // 隐藏小图，并显示大图
    thumbview.setalpha(0f);
    expandedimageview.setvisibility(view.visible);

    // 将大图的缩放中心点移到左上角。默认是从中心缩放
    expandedimageview.setpivotx(0f);
    expandedimageview.setpivoty(0f);

    //对大图进行缩放动画
    animatorset set = new animatorset();
    set.play(objectanimator.offloat(expandedimageview, view.x, startbounds.left, finalbounds.left))
        .with(objectanimator.offloat(expandedimageview, view.y, startbounds.top, finalbounds.top))
        .with(objectanimator.offloat(expandedimageview, view.scale_x, startscale, 1f))
        .with(objectanimator.offloat(expandedimageview, view.scale_y, startscale, 1f));
    set.setduration(mshortanimationduration);
    set.setinterpolator(new decelerateinterpolator());
    set.addlistener(new animatorlisteneradapter() {
      @override
      public void onanimationend(animator animation) {
        mcurrentanimator = null;
      }

      @override
      public void onanimationcancel(animator animation) {
        mcurrentanimator = null;
      }
    });
    set.start();
    mcurrentanimator = set;

    // 点击大图时，反向缩放大图，然后隐藏大图，显示小图。
    final float startscalefinal = startscale;
    expandedimageview.setonclicklistener(new view.onclicklistener() {
      @override
      public void onclick(view view) {
        if (mcurrentanimator != null) {
          mcurrentanimator.cancel();
        }

        animatorset set = new animatorset();
        set.play(objectanimator
            .offloat(expandedimageview, view.x, startbounds.left))
            .with(objectanimator
                .offloat(expandedimageview,
                    view.y,startbounds.top))
            .with(objectanimator
                .offloat(expandedimageview,
                    view.scale_x, startscalefinal))
            .with(objectanimator
                .offloat(expandedimageview,
                    view.scale_y, startscalefinal));
        set.setduration(mshortanimationduration);
        set.setinterpolator(new decelerateinterpolator());
        set.addlistener(new animatorlisteneradapter() {
          @override
          public void onanimationend(animator animation) {
            thumbview.setalpha(1f);
            expandedimageview.setvisibility(view.gone);
            mcurrentanimator = null;
          }

          @override
          public void onanimationcancel(animator animation) {
            thumbview.setalpha(1f);
            expandedimageview.setvisibility(view.gone);
            mcurrentanimator = null;
          }
        });
        set.start();
        mcurrentanimator = set;
      }
    });
  }
}

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。