图片过大处理

灰太狼 2022-08-27 13:41 151阅读 0赞

package com.stu.activity;
    
    import android.app.Activity;
    import android.content.Intent;
    import android.database.Cursor;
    import android.graphics.Bitmap;
    import android.graphics.BitmapFactory;
    import android.media.ThumbnailUtils;
    import android.net.Uri;
    import android.os.Build;
    import android.os.Bundle;
    import android.provider.MediaStore;
    import android.view.View;
    import android.view.View.OnClickListener;
    import android.widget.Button;
    import android.widget.ImageView;
    import android.widget.Toast;
    
    import com.maizi.activity.R;
    
    public class MainActivity extends Activity {
    
    	Button carmBtn;
    	ImageView photo;
    	int PICTURE_GET = 200;
    
    	@Override
    	protected void onCreate(Bundle savedInstanceState) {
    		super.onCreate(savedInstanceState);
    		setContentView(R.layout.main_activity);
    		carmBtn = (Button) findViewById(R.id.bt_carmer);
    		photo = (ImageView) findViewById(R.id.iv_photo);
    
    		carmBtn.setOnClickListener(new OnClickListener() {
    
    			@Override
    			public void onClick(View v) {
    				Intent intent = new Intent();
    				intent.setAction(Intent.ACTION_GET_CONTENT);
    				intent.setType("image/*");
    				startActivityForResult(intent, PICTURE_GET);
    			}
    		});
    
    	}
    
    	@Override
    	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    		super.onActivityResult(requestCode, resultCode, data);
    		if (requestCode == PICTURE_GET && data != null) {
    			Uri uri = data.getData();
    			String imagePath = getAbsoluteImagePath(this, uri);
    			Bitmap bitmap = null;
    			try {
    				BitmapFactory.Options opts = new BitmapFactory.Options();
    				opts.inJustDecodeBounds = true;
    				BitmapFactory.decodeFile(imagePath, opts);
    				opts.inSampleSize = computeSampleSize(opts, -1, 700*780);  
    				opts.inJustDecodeBounds = false;
    				bitmap = BitmapFactory.decodeFile(imagePath, opts);
    				photo.setImageBitmap(bitmap);
    			} catch (OutOfMemoryError e) {// 这个异常是可以捕捉的，习惯性写上去
    				Toast.makeText(MainActivity.this, "图片太大", Toast.LENGTH_SHORT).show();
    				return;
    			}
    		}
    	}
    
    	// 获取图片的路径
    	public static String getAbsoluteImagePath(Activity mContext, Uri uri) {
    		String[] proj = { MediaStore.Images.Media.DATA };
    		Cursor cursor = mContext.managedQuery(uri, proj, null, null, null);
    		int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
    		cursor.moveToFirst();
    		String res = cursor.getString(column_index);
    		try {
    			// 4.0以上的版本会自动关闭 (4.0--14;; 4.0.3--15)
    			if (Integer.parseInt(Build.VERSION.SDK) < 14) {
    				cursor.close();
    			}
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    		return res;
    	}
    
    	
    	
    	/**
    	 * 
    	 * @date   2014-6-8    下午11:31:25   Android源码动态算缩小值
    	 */
    	public static int computeSampleSize(BitmapFactory.Options options,
    		int minSideLength, int maxNumOfPixels) {
    		int initialSize = computeInitialSampleSize(options, minSideLength,maxNumOfPixels);
    		int roundedSize;
    		if (initialSize <= 8) {
    			roundedSize = 1;
    			while (roundedSize < initialSize) {
    				roundedSize <<= 1;
    			}
    		} else {
    			roundedSize = (initialSize + 7) / 8 * 8;
    		}
    		return roundedSize;
    	}
    
    	public static int computeInitialSampleSize(BitmapFactory.Options options,int minSideLength, int maxNumOfPixels) {
    		double w = options.outWidth;
    		double h = options.outHeight;
    		int lowerBound = (maxNumOfPixels == -1) ? 1 : (int) Math.ceil(Math.sqrt(w * h / maxNumOfPixels));
    		int upperBound = (minSideLength == -1) ? 128 : (int) Math.min(Math.floor(w / minSideLength), Math.floor(h / minSideLength));
    		if (upperBound < lowerBound) {
    			return lowerBound;
    		}
    		if ((maxNumOfPixels == -1) && (minSideLength == -1)) {
    			return 1;
    		} else if (minSideLength == -1) {
    			return lowerBound;
    		} else {
    			return upperBound;
    		}
    	}
    
    }