Android 实例讲解添加本地图片和调用系统拍照图片

今天药忘吃喽~ 2022-08-13 03:30 265阅读 0赞

在项目的开发过程我们离不开图片，而有时候需要调用本地的图片，有时候需要调用拍照图片。同时实现拍照的方法有两种，一种是调用系统拍照功能，另一种是自定义拍照功能。而本博文目前只讲解第一种方法，第二种方法后期在加以讲解。

添加本地图片和调用系统拍照图片主要是通过调用acitivity跳转startActivityForResult(Intent intent, int requestCode)方法和activity返回结果onActivityResult(int requestCode, int resultCode, Intent data)方法来实现的。具体实现代码如下：

一.添加本地图片

Intent intent = new Intent();
    	/* 开启Pictures画面Type设定为image */
    	intent.setType(IMAGE_TYPE);
    	/* 使用Intent.ACTION_GET_CONTENT这个Action */
    	intent.setAction(Intent.ACTION_GET_CONTENT);
    	/* 取得相片后返回本画面 */
    	startActivityForResult(intent, LOCAL_IMAGE_CODE);</span>

Uri uri = data.getData();
    	url = uri.toString().substring(uri.toString().indexOf("///") + 2);
    	if (url.contains(".jpg") && url.contains(".png")) {
    	Toast.makeText(this, "请选择图片", Toast.LENGTH_SHORT).show();
    		return;
    	}
    	bitmap = HelpUtil.getBitmapByUrl(url);

二.调用系统拍照图片

String fileName = "IMG_" + curFormatDateStr + ".png";
    	Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    	intent.putExtra(MediaStore.EXTRA_OUTPUT,Uri.fromFile(new File(rootUrl, fileName)));
    	intent.putExtra("fileName", fileName);
    	startActivityForResult(intent, CAMERA_IMAGE_CODE);

url = rootUrl + "/" + "IMG_" + curFormatDateStr + ".png";
    	bitmap = HelpUtil.getBitmapByUrl(url);
    	showImageIv.setImageBitmap(HelpUtil.createRotateBitmap(bitmap));

注意：由于拍照所得图片放在ImageView中自动逆时针旋转了90度，当显示的实现需要顺时针旋转90度，达到正常显示水平，方法如下

/**
    	 * bitmap旋转90度
    	 * 
    	 * @param bitmap
    	 * @return
    	 */
    	public static Bitmap createRotateBitmap(Bitmap bitmap) {
    		if (bitmap != null) {
    			Matrix m = new Matrix();
    			try {
    				m.setRotate(90, bitmap.getWidth() / 2, bitmap.getHeight() / 2);// 90就是我们需要选择的90度
    				Bitmap bmp2 = Bitmap.createBitmap(bitmap, 0, 0,
    						bitmap.getWidth(), bitmap.getHeight(), m, true);
    				bitmap.recycle();
    				bitmap = bmp2;
    			} catch (Exception ex) {
    				System.out.print("创建图片失败！" + ex);
    			}
    		}
    		return bitmap;
    	}

三.实例给出整个效果的详细代码

1.效果图

![Center][]![Center 1][]

2.布局文件activity\_main.xml

3.主类文件MainActivity.java

package com.example.insertimagedemo;
    
    import java.io.File;
    import java.util.Calendar;
    
    import android.app.Activity;
    import android.content.Intent;
    import android.graphics.Bitmap;
    import android.net.Uri;
    import android.os.Bundle;
    import android.os.Environment;
    import android.provider.MediaStore;
    import android.util.Log;
    import android.view.View;
    import android.view.View.OnClickListener;
    import android.widget.Button;
    import android.widget.ImageView;
    import android.widget.TextView;
    import android.widget.Toast;
    
    public class MainActivity extends Activity implements OnClickListener {
    
    	private static final int LOCAL_IMAGE_CODE = 1;
    	private static final int CAMERA_IMAGE_CODE = 2;
    	private static final String IMAGE_TYPE = "image/*";
    	private String rootUrl = null;
    	private String curFormatDateStr = null;
    
    	private Button localImgBtn, cameraImgBtn;
    	private TextView showUrlTv;
    	private ImageView showImageIv;
    
    	@Override
    	protected void onCreate(Bundle savedInstanceState) {
    		super.onCreate(savedInstanceState);
    		setContentView(R.layout.activity_main);
    		findById();
    		initData();
    	}
    
    	/**
    	 * 初始化view
    	 */
    	private void findById() {
    		localImgBtn = (Button) this.findViewById(R.id.id_local_img_btn);
    		cameraImgBtn = (Button) this.findViewById(R.id.id_camera_img_btn);
    		showUrlTv = (TextView) this.findViewById(R.id.id_show_url_tv);
    		showImageIv = (ImageView) this.findViewById(R.id.id_image_iv);
    
    		localImgBtn.setOnClickListener(this);
    		cameraImgBtn.setOnClickListener(this);
    	}
    
    	/**
    	 * 初始化相关data
    	 */
    	private void initData() {
    		rootUrl = Environment.getExternalStorageDirectory().getPath();
    	}
    
    	@Override
    	public void onClick(View v) {
    		switch (v.getId()) {
    		case R.id.id_local_img_btn:
    			processLocal();
    			break;
    		case R.id.id_camera_img_btn:
    			processCamera();
    			break;
    		}
    	}
    
    	/**
    	 * 处理本地图片btn事件
    	 */
    	private void processLocal() {
    		Intent intent = new Intent();
    		/* 开启Pictures画面Type设定为image */
    		intent.setType(IMAGE_TYPE);
    		/* 使用Intent.ACTION_GET_CONTENT这个Action */
    		intent.setAction(Intent.ACTION_GET_CONTENT);
    		/* 取得相片后返回本画面 */
    		startActivityForResult(intent, LOCAL_IMAGE_CODE);
    	}
    
    	/**
    	 * 处理camera图片btn事件
    	 */
    	private void processCamera() {
    		curFormatDateStr = HelpUtil.getDateFormatString(Calendar.getInstance()
    				.getTime());
    		String fileName = "IMG_" + curFormatDateStr + ".png";
    		Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    		intent.putExtra(MediaStore.EXTRA_OUTPUT,
    				Uri.fromFile(new File(rootUrl, fileName)));
    		intent.putExtra("fileName", fileName);
    		startActivityForResult(intent, CAMERA_IMAGE_CODE);
    	}
    
    	/**
    	 * 处理Activity跳转后返回事件
    	 */
    	@Override
    	public void onActivityResult(int requestCode, int resultCode, Intent data) {
    		if (resultCode == RESULT_OK) {
    			String url = "";
    			Bitmap bitmap = null;
    			if (requestCode == LOCAL_IMAGE_CODE) {
    				Uri uri = data.getData();
    				url = uri.toString().substring(
    						uri.toString().indexOf("///") + 2);
    				Log.e("uri", uri.toString());
    				if (url.contains(".jpg") && url.contains(".png")) {
    					Toast.makeText(this, "请选择图片", Toast.LENGTH_SHORT).show();
    					return;
    				}
    				bitmap = HelpUtil.getBitmapByUrl(url);
    				showImageIv.setImageBitmap(HelpUtil.getBitmapByUrl(url));
    
    				/**
    				 * 获取bitmap另一种方法
    				 * 
    				 * ContentResolver cr = this.getContentResolver(); bitmap =
    				 * HelpUtil.getBitmapByUri(uri, cr);
    				 */
    
    			} else if (requestCode == CAMERA_IMAGE_CODE) {
    				url = rootUrl + "/" + "IMG_" + curFormatDateStr + ".png";
    				bitmap = HelpUtil.getBitmapByUrl(url);
    				showImageIv.setImageBitmap(HelpUtil.createRotateBitmap(bitmap));
    
    				/**
    				 * 获取bitmap另一种方法
    				 * 
    				 * File picture = new File(url); 
    				 * Uri uri = Uri.fromFile(picture); 
    				 * ContentResolver cr = this.getContentResolver(); 
    				 * bitmap = HelpUtil.getBitmapByUri(uri, cr);
    				 */
    			}
    
    			showUrlTv.setText(url);
    		} else {
    			Toast.makeText(this, "没有添加图片", Toast.LENGTH_SHORT).show();
    		}
    
    	}
    }

4.帮助类文件HelpUtil.java

package com.example.insertimagedemo;
    
    import java.io.FileInputStream;
    import java.io.FileNotFoundException;
    import java.io.IOException;
    import java.text.SimpleDateFormat;
    import java.util.Date;
    
    import android.annotation.SuppressLint;
    import android.content.ContentResolver;
    import android.graphics.Bitmap;
    import android.graphics.BitmapFactory;
    import android.graphics.Matrix;
    import android.net.Uri;
    
    public class HelpUtil {
    	/**
    	 * 根据图片路径获取本地图片的Bitmap
    	 * 
    	 * @param url
    	 * @return
    	 */
    	public static Bitmap getBitmapByUrl(String url) {
    		FileInputStream fis = null;
    		Bitmap bitmap = null;
    		try {
    			fis = new FileInputStream(url);
    			bitmap = BitmapFactory.decodeStream(fis);
    
    		} catch (FileNotFoundException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    			bitmap = null;
    		} finally {
    			if (fis != null) {
    				try {
    					fis.close();
    				} catch (IOException e) {
    					// TODO Auto-generated catch block
    					e.printStackTrace();
    				}
    				fis = null;
    			}
    		}
    
    		return bitmap;
    	}
    
    	/**
    	 * bitmap旋转90度
    	 * 
    	 * @param bitmap
    	 * @return
    	 */
    	public static  Bitmap createRotateBitmap(Bitmap bitmap) {
    		if (bitmap != null) {
    			Matrix m = new Matrix();
    			try {
    				m.setRotate(90, bitmap.getWidth() / 2, bitmap.getHeight() / 2);// 90就是我们需要选择的90度
    				Bitmap bmp2 = Bitmap.createBitmap(bitmap, 0, 0,
    						bitmap.getWidth(), bitmap.getHeight(), m, true);
    				bitmap.recycle();
    				bitmap = bmp2;
    			} catch (Exception ex) {
    				System.out.print("创建图片失败！" + ex);
    			}
    		}
    		return bitmap;
    	}
    	
    	public static Bitmap getBitmapByUri(Uri uri,ContentResolver cr){
    		Bitmap bitmap = null;
    		try {
    			bitmap = BitmapFactory.decodeStream(cr
    					 .openInputStream(uri));
    		} catch (FileNotFoundException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    			bitmap = null;
    		}
    		return bitmap;
    	}
    
    	/**
    	 * 获取格式化日期字符串
    	 * @param date
    	 * @return
    	 */
    	@SuppressLint("SimpleDateFormat")
    	public static String getDateFormatString(Date date) {
    		if (date == null)
    			date = new Date();
    		String formatStr = new String();
    		SimpleDateFormat matter = new SimpleDateFormat("yyyyMMdd_HHmmss");
    		formatStr = matter.format(date);
    		return formatStr;
    	}
    }

以前就是本博文所有内容，谢谢品读。

源码地址：[http://download.csdn.net/detail/a123demi/8027697][http_download.csdn.net_detail_a123demi_8027697]

[Center]: https://img-blog.csdn.net/20141012070312903?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvYTEyM2RlbWk=/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center
[Center 1]: /images/20220810/a399d3f330f64d7e918de61ca7f38563.png
[http_download.csdn.net_detail_a123demi_8027697]: http://download.csdn.net/detail/a123demi/8027697