android点击后图片变大,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,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,startBounds.left))

.with(ObjectAnimator

.ofFloat(expandedImageView,startBounds.top))

.with(ObjectAnimator

.ofFloat(expandedImageView,startScaleFinal))

.with(ObjectAnimator

.ofFloat(expandedImageView,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编程小技巧。

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