ImageView 实现从手机相册中获取照片，并可以进行裁剪或者适屏展示

此例子是根据观看了老罗视频整理的，贴上代码，方便大家学习

 

 activity_main.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
     >

    <Button
        android:id="@+id/select"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="选择图片" />
    <Button
        android:id="@+id/cut"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="显示裁剪之后的图片" />
    <ImageView 
        android:id="@+id/image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

</LinearLayout>

 

 

main.java:

package com.example.imageview_cut;

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

public class MainActivity extends Activity implements OnClickListener{
 private Button select,cut;
 private ImageView imageView;
 private static  final int image_select=1;
 private static final int image_cut=2;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  select=(Button) findViewById(R.id.select);
  cut=(Button) findViewById(R.id.cut);
  imageView=(ImageView) findViewById(R.id.image);
  select.setOnClickListener(this);
  cut.setOnClickListener(this);
 }

 @Override
 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
  // TODO Auto-generated method stub
  super.onActivityResult(requestCode, resultCode, data);
  if (resultCode==RESULT_OK) {
   //处理图片按照手机的屏幕大小显示
   if (requestCode==image_select) {
    Uri uri=data.getData();//获得图片的路径
    int dw=getWindowManager().getDefaultDisplay().getWidth();
    int dh=getWindowManager().getDefaultDisplay().getHeight()/2;
    try {
     BitmapFactory.Options options=new BitmapFactory.Options();
     options.inJustDecodeBounds=true;//允许查询图片不是按照像素分配给内存
     Bitmap bmpBitmap=BitmapFactory.decodeStream(getContentResolver().openInputStream(uri),null,options);
     //对图片的宽度和高度对应手机屏幕进行匹配
     int hRatio=(int)Math.ceil(options.outHeight/(float)dh);
     //大于1，表示图片的高宽度大于手机屏幕的高宽度,
     int wRatio=(int)Math.ceil(options.outWidth/(float)dw);
     //缩放到1/radio的尺寸
     if (hRatio>1||wRatio>1) {
      if (hRatio>wRatio) {
       options.inSampleSize=hRatio;
      }else {
       options.inSampleSize=wRatio;
      }
     }
     options.inJustDecodeBounds=false;
     //对图片进行适屏
     bmpBitmap=BitmapFactory.decodeStream(getContentResolver().openInputStream(uri), null, options);
     imageView.setImageBitmap(bmpBitmap);
    } catch (Exception e) {
     // TODO: handle exception
    }
      
    
   }else if (requestCode==image_cut) {
    Bitmap bit=data.getParcelableExtra("data");
    imageView.setImageBitmap(bit);
   }   
  }
 }
 public void onClick(View v) {
  switch (v.getId()) {
  case R.id.select:
   //如何提取手机的图片，并且进行选择图片的功能
   Intent intent=new Intent(Intent.ACTION_PICK, 
         android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
   startActivityForResult(intent, image_select);
   break;

  case R.id.cut:
   Intent intent2=getImageClipIntent();
   startActivityForResult(intent2, image_cut);
   break;
  }
  
 }

 private Intent getImageClipIntent() {
  Intent intent =new Intent(Intent.ACTION_GET_CONTENT, null);
  //实现对图片的裁剪，必须要设置图片的属性和大小
  intent.setType("image/*");
  intent.putExtra("crop", "true");//滑动选中图片区域
  intent.putExtra("aspectX", 1);//表示剪切框的比例 1：
  intent.putExtra("aspectY", 1);
  intent.putExtra("outputX", 80);//指定输出图片的大小
  intent.putExtra("outputY", 80);
  intent.putExtra("return-data", true);
  
  return intent;
 }

 

}