调取系统相机、并将图片展示在ImageView上

package com.ting.textcover;

import java.io.File;

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.os.Environment;
import android.os.SystemClock;
import android.provider.MediaStore;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;

/**
 *   调取系统相机、并将图片展示在ImageView上
 * @author siva
 *
 */
public class MainActivity extends Activity {

	
	private Button btn ;
	private ImageView image;
	private String pathName;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        btn = (Button) findViewById(R.id.btn);
        image = (ImageView) findViewById(R.id.iamgeView);
        pathName = Environment.getExternalStorageDirectory()+"/image.jpg";
        btn.setOnClickListener(btnlistener);
        
    }
    private OnClickListener btnlistener = new OnClickListener() {
		
		@Override
		public void onClick(View arg0) {
			// TODO Auto-generated method stub
			Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
			//用户设置一个临时保存文件的地址,每次都会被替换掉
			Uri newFileUri = Uri.fromFile(new File(pathName));
			intent.putExtra(MediaStore.EXTRA_OUTPUT, newFileUri);
			startActivityForResult(intent, 1);
		}
	};
	@Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
		// TODO Auto-generated method stub
    
		if (resultCode==RESULT_OK) {
			switch (requestCode) {
			case 1:
				BitmapFactory.Options options = new BitmapFactory.Options();
				options.inJustDecodeBounds = true;  //这时候decode的bitmap为null,只是宽高放到其中
				Bitmap bitmap = BitmapFactory.decodeFile(pathName,options);
				options.inJustDecodeBounds = false;
				//因为是等比例缩放、因此只设置一个即可
				int be = options.outHeight/300;
				if(be<=0){
					be=1;
				}
				options.inSampleSize = be;  //缩放比例
				//重新读入图片，此时的bitmap不是null值；若此处出现null ，查看pathname是否有问题
				bitmap = BitmapFactory.decodeFile(pathName,options);
				int withd = bitmap.getWidth();
				int height = bitmap.getHeight();
				System.out.println(withd+"===="+height);
				image.setImageBitmap(bitmap);
				// 将图片保存在SD卡上
				break;
			default:
				break;
			}
		}
	
	}
		
	
	
    
}