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; 

        } 

     

     

}