android 裁剪图片大小 控制图片尺寸

用BitmapFactory获取适合屏幕大小的图片 和自带的图片裁剪工具

package com.lin.image; 

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView; 

public class ImageScaleActivity extends Activity  implements View.OnClickListener{
    /** Called when the activity is first created. */
    private Button selectImageBtn;
    private Button cutImageBtn;
    private ImageView imageView;
    private static final int  IMAGE_SELECT=1;
    private static final int  IMAGE_CUT=2;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main); 

        selectImageBtn=(Button)findViewById(R.id.selectImageBtn);
        cutImageBtn=(Button)findViewById(R.id.catImageBtn);
        imageView=(ImageView)findViewById(R.id.imageView); 

        cutImageBtn.setOnClickListener(this);
        selectImageBtn.setOnClickListener(this); 

    } 

    @Override
    public void onClick(View v) { 

<span style="white-space:pre">        </span>//截取适合屏幕大小的图片
        if(v==selectImageBtn){
        Intent intent=new Intent(Intent.ACTION_PICK,
                android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
            startActivityForResult(intent, IMAGE_SELECT);
        }//一般用于头像等需要设置指定大小
        else if(v==cutImageBtn){
            Intent intent=getImageClipIntent();
            startActivityForResult(intent, IMAGE_CUT);
        }
    } 

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
        // TODO Auto-generated method stub
        if(resultCode==RESULT_OK){
            if(requestCode==IMAGE_SELECT){
            Uri imageFileUri =intent.getData();
            int dw=getWindowManager().getDefaultDisplay().getWidth();
            int dh=getWindowManager().getDefaultDisplay().getHeight()/2;
            //已屏幕宽 和一般的高作为图片显示的最大尺寸
            try{
                BitmapFactory.Options factory=new BitmapFactory.Options();
                factory.inJustDecodeBounds=true; //当为true时  允许查询图片不为 图片像素分配内存
                Bitmap bmp=BitmapFactory.decodeStream(getContentResolver()
                        .openInputStream(imageFileUri),null,factory);
                int hRatio=(int)Math.ceil(factory.outHeight/(float)dh); //图片是高度的几倍
                int wRatio=(int)Math.ceil(factory.outWidth/(float)dw); //图片是宽度的几倍
                System.out.println("hRatio:"+hRatio+"  wRatio:"+wRatio);
                //缩小到  1/ratio的尺寸和 1/ratio^2的像素
                if(hRatio>1||wRatio>1){
                    if(hRatio>wRatio){
                        factory.inSampleSize=hRatio;
                    }
                    else
                        factory.inSampleSize=wRatio;
                }
                factory.inJustDecodeBounds=false;
                 bmp=BitmapFactory.decodeStream(getContentResolver()
                        .openInputStream(imageFileUri),null,factory);
                 imageView.setImageBitmap(bmp);
            }catch(Exception ex){ 

            }
            }
            else if(requestCode==IMAGE_CUT){
                Bitmap bmp=intent.getParcelableExtra("data");
                imageView.setImageBitmap(bmp);
            }
        } 

    }
        /**
         * 获取剪切后的图片
         */
        public static Intent getImageClipIntent() { 

            Intent intent = new Intent(Intent.ACTION_GET_CONTENT, null);
            intent.setType("image/*");
            intent.putExtra("crop", "true");
            intent.putExtra("aspectX", 1);//裁剪框比例
            intent.putExtra("aspectY", 1);
            intent.putExtra("outputX", 80);//输出图片大小
            intent.putExtra("outputY", 80);
            intent.putExtra("return-data", true);
            return intent;
        } 

}

摘自 dikeboy1234的专栏