安卓课程二十三 ImageView实现适屏和裁剪图片

AndroidManifest.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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" 
    android:orientation="vertical"
    >
    <Button
        android:id="@+id/selectImageBtn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/buttton_seleclocal" />
    
     <Button
         android:id="@+id/cutImageBtn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/buttton_cutImg" />
    <ImageView  android:id="@+id/imageView"
        android:contentDescription="@string/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

</LinearLayout>

 MainActivity.java

package com.example.ImageView2;

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.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;

public class MainActivity extends Activity implements OnClickListener {
	private Button selectImageBtn;
	private Button cutImageBtn;
	
	private ImageView imageView;
	/**
	 * 声明两个静态变量，主要用于意图的返回的标志
	 */
	private static final int IMAGE_SELECT = 1;
	private static final int IMAGE_CUT = 2;
	
	
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		selectImageBtn = (Button) findViewById(R.id.selectImageBtn);
		cutImageBtn = (Button) findViewById(R.id.cutImageBtn);
		
		selectImageBtn.setOnClickListener(this) ;
		cutImageBtn.setOnClickListener(this) ;
	}
 
	

	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
		super.onActivityResult(requestCode, resultCode, data);
		if(resultCode == RESULT_OK){
			//选取图片，按照手机的屏幕大小显示
			if(requestCode== IMAGE_SELECT){
				Uri uri = data.getData();
				//获得屏幕的宽度
				int dw = getWindowManager().getDefaultDisplay().getWidth();
				int dh = getWindowManager().getDefaultDisplay().getHeight()/2;
				try{
					//实现对图片进行裁剪的是一个匿名内部类
					BitmapFactory.Options factory = new BitmapFactory.Options();
					factory.inJustDecodeBounds = true;//设置为true,允许查询图片不是按照像素分配给内存
					//获取图片
					 Bitmap bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(uri), null, factory);
					 //对图片的宽度和高度对应手机的屏幕进行匹配
					 //如果大于1,表示图片高度大小大于手机高度
					 int hRatio = (int) Math.ceil(factory.outHeight/(float)dh);
					//如果大于1,表示图片宽度大小大于手机宽度
					 int wRatio = (int) Math.ceil(factory.outWidth/(float)dw);
					 
					 //缩放到宽度为1/radio的尺寸和1/radio^2像素
					 if(hRatio>1 || wRatio>1) {
						 if(hRatio>wRatio){
							 factory.inSampleSize=hRatio;
						 }else  {
							 factory.inSampleSize=wRatio;
						 }
					 }
					 factory.inJustDecodeBounds = false;
					 //裁剪图片,进行适屏的操作
					 bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(uri), null, factory);
					 imageView.setImageBitmap(bitmap);
				}catch(Exception e){}
			}else 	if(requestCode== IMAGE_CUT){
				//进行裁剪操作
				Bitmap bitmap = data.getParcelableExtra("data");
				imageView.setImageBitmap(bitmap);
				
			}
		}
	}



	public void onClick(View v) {
		switch(v.getId()){
		case R.id.selectImageBtn:
			//声明一个意图，使用android自身带的一个意图说明，提取手机的图片.
			//参数指定提取路径
			Intent intent = new Intent(Intent.ACTION_PICK,
					android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
			startActivityForResult(intent, IMAGE_SELECT);
			break;
		case R.id.cutImageBtn:
			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，必须设置图片的属性和大小
		intent.setType("image/*");//获取任意的图片类型
		intent.putExtra("crop", "true");//滑动选中图片区域
		intent.putExtra("aspectX", 1);//设置剪贴框的比列大小
		intent.putExtra("aspectY", 1);//设置剪贴框的比列大小
		
		intent.putExtra("outputX", 80);//设置输出图片大小
		intent.putExtra("outputY", 80);//设置输出图片大小
		intent.putExtra("return-data", true);//表示有返回值
		return intent;
	}

}

 使用豌豆荚链接，选择图片上传一个图片进行测试