这篇文章主要讲解了“android新浪微博图片缩放效果怎么实现”，文中的讲解内容简单清晰，易于学习与理解，下面请大家跟着小编的思路慢慢深入，一起来研究和学习“android新浪微博图片缩放效果怎么实现”吧！
Android开发中有时会用到图片缩放效果，即点击图片时显示缩放按钮，过一会消失。本文就根据新浪微博的图片缩放给大家写一个实例，以供参考。下面直接上代码。
package com.Johnson.image.zoom; import android.app.Activity; import android.app.Dialog; import android.app.ProgressDialog; import android.content.DialogInterface; import android.content.DialogInterface.OnKeyListener; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Matrix; import android.os.Bundle; import android.os.Handler; import android.util.DisplayMetrics; import android.util.Log; import android.view.KeyEvent; import android.view.MotionEvent; import android.view.View; import android.view.View.OnClickListener; import android.widget.ImageView; import android.widget.LinearLayout; import android.widget.RelativeLayout; import android.widget.ZoomControls; public class MainActivity extends Activity { /** Called when the activity is first created. */ private final int LOADING_IMAGE = 1; public static String KEY_IMAGEURI = "ImageUri"; private ZoomControls zoom; private ImageView mImageView; private LinearLayout layoutImage; private int displayWidth; private int displayHeight; /**图片资源*/ private Bitmap bmp; /**宽的缩放比例*/ private float scaleWidth = 1; /**高的缩放比例*/ private float scaleHeight = 1; /**用来计数放大+1 缩小-1*/ private int zoomNumber=0; /**点击屏幕显示缩放按钮，三秒消失*/ private int showTime=3000; RelativeLayout rl; Handler mHandler = new Handler(); private Runnable task = new Runnable() { public void run() { zoom.setVisibility(View.INVISIBLE); } }; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); //showDialog(LOADING_IMAGE); //图片是从网络上获取的话，需要加入滚动条 bmp=BitmapFactory.decodeResource(getResources(), R.drawable.image); //removeDialog(LOADING_IMAGE); initZoom(); } @Override protected Dialog onCreateDialog(int id) { switch (id) { case LOADING_IMAGE: { final ProgressDialog dialog = new ProgressDialog(this); dialog.setOnKeyListener(new OnKeyListener() { @Override public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) { if (keyCode == KeyEvent.KEYCODE_BACK) { finish(); } return false; } }); dialog.setMessage("正在加载图片请稍后..."); dialog.setIndeterminate(true); dialog.setCancelable(true); return dialog; } } return null; } public void initZoom() { /* 取得屏幕分辨率大小 */ DisplayMetrics dm = new DisplayMetrics(); getWindowManager().getDefaultDisplay().getMetrics(dm); displayWidth = dm.widthPixels; displayHeight = dm.heightPixels; mImageView = (ImageView) findViewById(R.id.myImageView); mImageView.setImageBitmap(bmp); layoutImage = (LinearLayout) findViewById(R.id.layoutImage); mImageView.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub /** * 在图片上和整个view上同时添加点击监听捕捉屏幕 * 点击事件，来显示放大缩小按钮 * */ zoom.setVisibility(View.VISIBLE); mHandler.removeCallbacks(task); mHandler.postDelayed(task, showTime); } }); layoutImage.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub zoom.setVisibility(View.VISIBLE); mHandler.removeCallbacks(task); mHandler.postDelayed(task, showTime); } }); zoom = (ZoomControls) findViewById(R.id.zoomcontrol); zoom.setIsZoomInEnabled(true); zoom.setIsZoomOutEnabled(true); // 图片放大 zoom.setOnZoomInClickListener(new OnClickListener() { public void onClick(View v) { big(); } }); // 图片减小 zoom.setOnZoomOutClickListener(new OnClickListener() { public void onClick(View v) { small(); } }); zoom.setVisibility(View.VISIBLE); mHandler.postDelayed(task, showTime); } @Override public boolean onTouchEvent(MotionEvent event) { // TODO Auto-generated method stub /** * 在图片上和整个view上同时添加点击监听捕捉屏幕 * 点击事件，来显示放大缩小按钮 * */ zoom.setVisibility(View.VISIBLE); mHandler.removeCallbacks(task); mHandler.postDelayed(task, showTime); return false; } @Override public boolean onKeyDown(int keyCode, KeyEvent event) { // TODO Auto-generated method stub super.onKeyDown(keyCode, event); return true; } /* 图片缩小的method */ private void small() { --zoomNumber; int bmpWidth = bmp.getWidth(); int bmpHeight = bmp.getHeight(); Log.i("","bmpWidth = " + bmpWidth + ", bmpHeight = " + bmpHeight); /* 设置图片缩小的比例 */ double scale = 0.8; /* 计算出这次要缩小的比例 */ scaleWidth = (float) (scaleWidth * scale); scaleHeight = (float) (scaleHeight * scale); /* 产生reSize后的Bitmap对象 */ Matrix matrix = new Matrix(); matrix.postScale(scaleWidth, scaleHeight); Bitmap resizeBmp = Bitmap.createBitmap(bmp, 0, 0, bmpWidth, bmpHeight, matrix, true); mImageView.setImageBitmap(resizeBmp); /* 限制缩小尺寸 */ if ((scaleWidth * scale * bmpWidth < bmpWidth / 4 || scaleHeight * scale * bmpHeight > bmpWidth /4 || scaleWidth * scale * bmpWidth > displayWidth / 5 || scaleHeight * scale * bmpHeight > displayHeight / 5)&&(zoomNumber==-1) ){ zoom.setIsZoomOutEnabled(false); } else { zoom.setIsZoomOutEnabled(true); } zoom.setIsZoomInEnabled(true); System.gc(); } /* 图片放大的method */ private void big() { ++zoomNumber; int bmpWidth = bmp.getWidth(); int bmpHeight = bmp.getHeight(); /* 设置图片放大的比例 */ double scale = 1.25; /* 计算这次要放大的比例 */ scaleWidth = (float) (scaleWidth * scale); scaleHeight = (float) (scaleHeight * scale); /* 产生reSize后的Bitmap对象 */ Matrix matrix = new Matrix(); matrix.postScale(scaleWidth, scaleHeight); Bitmap resizeBmp = Bitmap.createBitmap(bmp, 0, 0, bmpWidth, bmpHeight, matrix, true); mImageView.setImageBitmap(resizeBmp); /* 限制放大尺寸 */ if (scaleWidth * scale * bmpWidth > bmpWidth * 4 || scaleHeight * scale * bmpHeight > bmpWidth * 4 || scaleWidth * scale * bmpWidth > displayWidth * 5 || scaleHeight * scale * bmpHeight > displayHeight * 5) { zoom.setIsZoomInEnabled(false); } else { zoom.setIsZoomInEnabled(true); } zoom.setIsZoomOutEnabled(true); System.gc(); } }布局文件如下：
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android：orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/layout1"
>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/rl"
>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="19"
android:scrollbars="none"
android:fadingEdge="vertical"
android:layout_gravity="center"
android:gravity="center"
>
<HorizontalScrollView
android:layout_height="fill_parent"
android:layout_width="fill_parent"
android:scrollbars="none"
android:layout_gravity="center"
android:gravity="center"
android:id="@+id/hs"
>
<LinearLayout
android：orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/layoutImage"
android:layout_gravity="center"
android:gravity="center"
>
<ImageView
android:layout_gravity="center"
android:gravity="center"
android:id="@+id/myImageView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="19"
android:paddingTop="5dip"
android:paddingBottom="5dip"
/>
</LinearLayout>
</HorizontalScrollView >
</ScrollView>
<ZoomControls android:id="@+id/zoomcontrol"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_alignParentBottom="true"
>
</ZoomControls>
</RelativeLayout>
</FrameLayout>
感谢各位的阅读，以上就是“android新浪微博图片缩放效果怎么实现”的内容了，经过本文的学习后，相信大家对android新浪微博图片缩放效果怎么实现这一问题有了更深刻的体会，具体使用情况还需要大家实践验证。这里是亿速云，小编将为大家推送更多相关知识点的文章，欢迎关注！
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