Android 裁剪圖片大小 控制圖片尺寸

Android 用BitmapFactory獲取適合屏幕大小的圖片 和自帶的圖片裁剪工具

1. package com.lin.image;  
2.   
3. import android.app.Activity;  
4. import android.content.Intent;  
5. import android.graphics.Bitmap;  
6. import android.graphics.BitmapFactory;  
7. import android.net.Uri;  
8. import android.os.Bundle;  
9. import android.view.View;  
10. import android.widget.Button;  
11. import android.widget.ImageView;  
12.   
13. public class ImageScaleActivity extends Activity  implements View.OnClickListener{  
14.     /** Called when the activity is first created. */  
15.     private Button selectImageBtn;  
16.     private Button cutImageBtn;  
17.     private ImageView imageView;  
18.     private static final int  IMAGE_SELECT=1;  
19.     private static final int  IMAGE_CUT=2;  
20.     @Override  
21.     public void onCreate(Bundle savedInstanceState) {  
22.         super.onCreate(savedInstanceState);  
23.         setContentView(R.layout.main);  
24.           
25.         selectImageBtn=(Button)findViewById(R.id.selectImageBtn);  
26.         cutImageBtn=(Button)findViewById(R.id.catImageBtn);  
27.         imageView=(ImageView)findViewById(R.id.imageView);  
28.           
29.         cutImageBtn.setOnClickListener(this);  
30.         selectImageBtn.setOnClickListener(this);  
31.         
32.     }  
33.   
34.     @Override  
35.     public void onClick(View v) {  

1. //截取適合屏幕大小的圖片   
2.         if(v==selectImageBtn){  
3.         Intent intent=new Intent(Intent.ACTION_PICK,  
4.                 android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);  
5.             startActivityForResult(intent, IMAGE_SELECT);  
6.         }//一般用於頭像等需要設置指定大小   
7.         else if(v==cutImageBtn){  
8.             Intent intent=getImageClipIntent();  
9.             startActivityForResult(intent, IMAGE_CUT);  
10.         }  
11.     }  
12.   
13.     @Override  
14.     protected void onActivityResult(int requestCode, int resultCode, Intent intent) {  
15.         // TODO Auto-generated method stub   
16.         if(resultCode==RESULT_OK){  
17.             if(requestCode==IMAGE_SELECT){  
18.             Uri imageFileUri =intent.getData();  
19.             int dw=getWindowManager().getDefaultDisplay().getWidth();  
20.             int dh=getWindowManager().getDefaultDisplay().getHeight()/2;  
21.             //已屏幕寬 和一般的高作為圖片顯示的最大尺寸   
22.             try{  
23.                 BitmapFactory.Options factory=new BitmapFactory.Options();  
24.                 factory.inJustDecodeBounds=true; //當為true時  允許查詢圖片不為 圖片像素分配內存   
25.                 Bitmap bmp=BitmapFactory.decodeStream(getContentResolver()  
26.                         .openInputStream(imageFileUri),null,factory);  
27.                 int hRatio=(int)Math.ceil(factory.outHeight/(float)dh); //圖片是高度的幾倍   
28.                 int wRatio=(int)Math.ceil(factory.outWidth/(float)dw); //圖片是寬度的幾倍   
29.                 System.out.println("hRatio:"+hRatio+"  wRatio:"+wRatio);  
30.                 //縮小到  1/ratio的尺寸和 1/ratio^2的像素   
31.                 if(hRatio>1||wRatio>1){  
32.                     if(hRatio>wRatio){  
33.                         factory.inSampleSize=hRatio;   
34.                     }  
35.                     else  
36.                         factory.inSampleSize=wRatio;  
37.                 }  
38.                 factory.inJustDecodeBounds=false;  
39.                  bmp=BitmapFactory.decodeStream(getContentResolver()  
40.                         .openInputStream(imageFileUri),null,factory);  
41.                  imageView.setImageBitmap(bmp);  
42.             }catch(Exception ex){  
43.                   
44.             }  
45.             }  
46.             else if(requestCode==IMAGE_CUT){  
47.                 Bitmap bmp=intent.getParcelableExtra("data");  
48.                 imageView.setImageBitmap(bmp);  
49.             }  
50.         }  
51.           
52.     }  
53.         /** 
54.          * 獲取剪切後的圖片 
55.          */  
56.         public static Intent getImageClipIntent() {  
57.   
58.             Intent intent = new Intent(Intent.ACTION_GET_CONTENT, null);  
59.             intent.setType("image/*");  
60.             intent.putExtra("crop", "true");   
61.             intent.putExtra("aspectX", 1);//裁剪框比例   
62.             intent.putExtra("aspectY", 1);  
63.             intent.putExtra("outputX", 80);//輸出圖片大小   
64.             intent.putExtra("outputY", 80);  
65.             intent.putExtra("return-data", true);  
66.             return intent;  
67.         }  
68.       
69.       
70. }