Android图片操作工具类

package com.aliyun.oss.ossdemo;

import android.app.Activity;
import android.app.AlertDialog;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.util.Log;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

/**
* Created by yjs on 2015/12/7 0007.
* 完成显示图片操作
*/
public class ImageDisplayer {

private ImageView imageView;
private int height;
private int width;

public ImageDisplayer(ImageView imageView) {
this.imageView = imageView;
}

public ImageDisplayer(int height, int width) {
this.height = height;
this.width = width;
}

public static byte[] getBytesFromStream(InputStream stream) throws IOException {
{
ByteArrayOutputStream outStream = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len = 0;
while ((len = stream.read(buffer)) != -1) {
outStream.write(buffer, 0, len);
}
outStream.close();
return outStream.toByteArray();
}
}

//计算图片缩放比例
public static int calculateInSampleSize(
BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;

if (height > reqHeight || width > reqWidth) {

final int halfHeight = height / 2;
final int halfWidth = width / 2;

// Calculate the largest inSampleSize value that is a power of 2 and keeps both
// height and width larger than the requested height and width.
while ((halfHeight / inSampleSize) > reqHeight
&& (halfWidth / inSampleSize) > reqWidth) {
inSampleSize *= 2;
}
}

return inSampleSize;
}

//根据ImageView的大小自动缩放图片
public Bitmap autoResizeFromLocalFile(String picturePath) throws IOException {
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(picturePath, options);

// Calculate inSampleSize
int h = height;
int w = width;
if (imageView != null) {
h = imageView.getHeight();
w = imageView.getWidth();
}
options.inSampleSize = calculateInSampleSize(options, w, h);
Log.d("ImageHeight", String.valueOf(options.outHeight));
Log.d("ImageWidth", String.valueOf(options.outWidth));
Log.d("Height", String.valueOf(h));
Log.d("Width",String.valueOf(w));
//options.inSampleSize = 10;

Log.d("SampleSize", String.valueOf(options.inSampleSize));
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
return BitmapFactory.decodeFile(picturePath, options);

}

public Bitmap autoResizeFromBytes(byte[] data) {

// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeByteArray(data, 0, data.length, options);

int h = height;
int w = width;
if (imageView != null) {
h = imageView.getHeight();
w = imageView.getWidth();
}
options.inSampleSize = calculateInSampleSize(options, w, h);

Log.d("ImageHeight", String.valueOf(options.outHeight));
Log.d("ImageWidth", String.valueOf(options.outWidth));
Log.d("Height", String.valueOf(h));
Log.d("Width",String.valueOf(w));
//options.inSampleSize = 10;

Log.d("SampleSize", String.valueOf(options.inSampleSize));
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
return BitmapFactory.decodeByteArray(data, 0, data.length, options);
}

//根据ImageView大小自动缩放图片
public Bitmap autoResizeFromStream(InputStream stream) throws IOException {
byte[] data = getBytesFromStream(stream);
return autoResizeFromBytes(data);
}

public Bitmap autoResizeFromBitmap(Bitmap bm) {
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.outHeight = bm.getHeight();
options.outWidth = bm.getWidth();

int h = height;
int w = width;
if (imageView != null) {
h = imageView.getHeight();
w = imageView.getWidth();
}
int inSampleSize = calculateInSampleSize(options, w, h);
Log.d("ImageHeight", String.valueOf(options.outHeight));
Log.d("ImageWidth", String.valueOf(options.outWidth));
Log.d("Height", String.valueOf(h));
Log.d("Width",String.valueOf(w));
if (inSampleSize == 1) {
return bm;
}
else {
return Bitmap.createScaledBitmap(bm, bm.getWidth() / inSampleSize, bm.getHeight() / inSampleSize, true);
}
}
}