android开发中———从相册中选择照片，无法展示的问题

qq_27222947 2016-03-29 10:45:40

android开发中———从相册中选择照片

编译版本API 4.4.2 ，真机系统版本 4.4.4

问题：在真机测试时，从相册中取照片，无法展示。控制台没报错，log中也没找到对应错误。本人新手，求大神帮找出问题

代码如下：

MainActivity.java

package com.example.choosepictest;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;

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.provider.MediaStore;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;

public class MainActivity extends Activity {

public static final int TAKE_PHOTO = 1;

public static final int CROP_PHOTO = 2;

private Button takePhoto;

private ImageView picture;

private Uri imageUri;

private Button chooseFromAlbum;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

takePhoto = (Button) findViewById(R.id.take_photo);
picture = (ImageView) findViewById(R.id.picture);
takePhoto.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// 创建File对象，用于存储拍照后的图片
File outputImage = new File(Environment.getExternalStorageDirectory(), "tempImage.jpg");
try {
if (outputImage.exists()) {
outputImage.delete();
}
outputImage.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
imageUri = Uri.fromFile(outputImage);
Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
startActivityForResult(intent, TAKE_PHOTO); // 启动相机程序
}
});

//从相册中选择照片
chooseFromAlbum = (Button) findViewById(R.id.choose_from_album);
chooseFromAlbum.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// 创建File对象，用于存储选择的照片
File outputImage = new File(Environment.getExternalStorageDirectory(), "output_image.jpg");
try {
if (outputImage.exists()) {
outputImage.delete();
}
outputImage.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
imageUri = Uri.fromFile(outputImage);
Intent intent = new Intent("android.intent.action.GET_CONTENT");
//选择图片
intent.setType("image/*");

intent.putExtra("crop", true);
intent.putExtra("scale", true);
intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
startActivityForResult(intent, CROP_PHOTO);
}
});

}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (requestCode) {
case TAKE_PHOTO:
if (resultCode == RESULT_OK) {
Intent intent = new Intent("com.android.camera.action.CROP");
intent.setDataAndType(imageUri, "image/*");
intent.putExtra("scale", true);
intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
startActivityForResult(intent, CROP_PHOTO); // 启动裁剪程序
}
break;
case CROP_PHOTO:
if (resultCode == RESULT_OK) {
try {
Bitmap bitmap = BitmapFactory.decodeStream (getContentResolver().openInputStream(imageUri));
picture.setImageBitmap(bitmap); // 将裁剪后的照片显示出来
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
break;
default:
break;
}
}

}

activity_main.xml

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

<Button
android:id="@+id/take_photo"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="调用摄像头拍照" />

<Button
android:id="@+id/choose_from_album"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="从相册选择照片" />

<ImageView
android:id="@+id/picture"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal" />

</LinearLayout>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.choosepictest"
android:versionCode="1"
android:versionName="1.0" >

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

<uses-sdk
android:minSdkVersion="15"
android:targetSdkVersion="19" />

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme"
>
<activity
android:name=".MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>

</manifest>

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