Android 实例讲解添加本地图片和调用系统拍照图片

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

1.

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>

2.

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

1.

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);

2.

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





2.布局文件activity_main.xml

<RelativeLayout 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" >

<LinearLayout
android:id="@+id/id_insert_btns_ll"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:orientation="horizontal" >

<Button
android:id="@+id/id_local_img_btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="插入本地图片" />

<Button
android:id="@+id/id_camera_img_btn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="插入拍照图片" />
</LinearLayout>

<TextView
android:id="@+id/id_show_url_tv"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:layout_alignParentBottom="true"
android:textColor="#FF0000"
android:text="显示图片路径" />

<ImageView
android:id="@+id/id_image_iv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/id_insert_btns_ll"
android:layout_above="@id/id_show_url_tv"
android:layout_centerHorizontal="true"
/>
</RelativeLayout>

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