Android调用系统图库获取图片
我不学习没人要 人气:01、开发工具与关键技术：Eclipse、AndroidStudio
2、撰写时间：2020年05月28日
在做移动开发相信很多人都会用到调用系统的图库获取图片吧，那么今天我跟大家讲讲如何调用系统的图库获取图片呢！由于本次的内容有点多，所以，分几个步骤吧！废话就不多说啦！避免浪费大家的时间，回归正题。请看代码
第一步：在build.gradle的文件下确保安卓版本是6.0以上（targetSdkVersion 23 以上）
defaultConfig {
targetSdkVersion 29
}第二步：在manifests文件清单中添加权限
<!--允许程序设置内置sd卡的写权限--> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> <!--允许程序读写手机状态和身份--> <uses-permission android:name="android.permission.READ_PHONE_STATE" /> <!--注意：这个的包名后面的单词一定要小写，否则会报错--> <provider android:name="androidx.core.content.FileProvider" android:authorities="项目包名.fileprovider" android:exported="false" android:grantUriPermissions="true"> //这个一定要设置为true,否则不可以使用 <meta-data android:name="android.support.FILE_PROVIDER_PATHS" android:resource="@xml/file_paths" /> </provider>
第三步：在res的目录下的xml中添加file_paths.xml文件(这个是固定写法)
<?xml version="1.0" encoding="utf-8"?> <resources> <paths> <root-path name="root" path="." /> <cache-path name="image_cache" path="." /> </paths> </resources>
第四步：创建工具类
1、调用图库的MPermissionUtils 工具类
package com.example.hote.util;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.Build;
import android.provider.Settings;
import android.util.Log;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AlertDialog;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import androidx.fragment.app.Fragment;
import java.util.ArrayList;
import java.util.List;
/**
*
* <p>
* 6.0 运行时权限处理工具类。
*/
public class MPermissionUtils {
private static String TAG=MPermissionUtils.class.getSimpleName();
private static int mRequestCode = -1;
public static void requestPermissionsResult(Activity activity, int requestCode
, String[] permission, OnPermissionListener callback) {
requestPermissions(activity, requestCode, permission, callback);
}
public static void requestPermissionsResult(android.app.Fragment fragment, int requestCode
, String[] permission, OnPermissionListener callback) {
requestPermissions(fragment, requestCode, permission, callback);
}
public static void requestPermissionsResult(Fragment fragment, int requestCode
, String[] permission, OnPermissionListener callback) {
requestPermissions(fragment, requestCode, permission, callback);
}
/**
* 请求权限结果，对应onRequestPermissionsResult()方法。
*/
public static void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
if (requestCode == mRequestCode) {
if (verifyPermissions(grantResults)) {
if (mOnPermissionListener != null)
mOnPermissionListener.onPermissionGranted();
} else {
if (mOnPermissionListener != null)
mOnPermissionListener.onPermissionDenied();
}
//调试打印授权情况
Log.d(TAG,"-----------------------------权限授权信息------------------------------------");
for(int i=0,len=permissions.length;i<len;i++){
String strText="未知情况";
switch (grantResults[i]){
case 0:
strText="授权";
break;
case 1:
strText="被拒绝";
break;
}
Log.d(TAG,"权限："+permissions[i]+" 的授权情况为: "+strText);
}
Log.d(TAG,"-----------------------------------------------------------------------------");
}
}
/**
* 是否彻底拒绝了某项权限
*/
public static boolean hasAlwaysDeniedPermission(@NonNull Context context, @NonNull String... deniedPermissions) {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) return false;
boolean rationale;
for (String permission : deniedPermissions) {
rationale = ActivityCompat.shouldShowRequestPermissionRationale((Activity) getContext(context), permission);
if (!rationale) return true;
}
return false;
}
/**
* 显示提示对话框
*/
public static void showTipsDialog(final Context context) {
new AlertDialog.Builder(context)
.setTitle("提示信息")
.setMessage("当前应用缺少必要权限，该功能暂时无法使用。如若需要，请单击【确定】按钮前往设置中心进行权限授权。")
.setNegativeButton("取消", null)
.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
startAppSettings(context);
}
}).show();
}
//=============私有方法===================================
/**
* 请求权限处理
*
* @param object activity or fragment
* @param requestCode 请求码
* @param permissions 需要请求的权限
* @param callback 结果回调
*/
@TargetApi(Build.VERSION_CODES.M)
private static void requestPermissions(Object object, int requestCode
, String[] permissions, OnPermissionListener callback) {
checkCallingObjectSuitability(object);
mOnPermissionListener = callback;
if (checkPermissions(getContext(object), permissions)) {
if (mOnPermissionListener != null)
mOnPermissionListener.onPermissionGranted();
} else {
List<String> deniedPermissions = getDeniedPermissions(getContext(object), permissions);
int len = deniedPermissions.size();
if (len > 0) {
mRequestCode = requestCode;
String[] strDeniedPermissions = deniedPermissions.toArray(new String[len]);
if (object instanceof Activity) {
((Activity) object).requestPermissions(strDeniedPermissions, requestCode);
} else if (object instanceof Fragment) {
((Fragment) object).requestPermissions(strDeniedPermissions, requestCode);
} else if (object instanceof android.app.Fragment) {
((android.app.Fragment) object).requestPermissions(strDeniedPermissions, requestCode);
}
}
}
}
/**
* 获取上下文
*/
private static Context getContext(Object object) {
Context context;
if (object instanceof Fragment) {
context = ((Fragment) object).getActivity();
} else if (object instanceof android.app.Fragment) {
context = ((android.app.Fragment) object).getActivity();
} else {
context = (Activity) object;
}
return context;
}
/**
* 启动当前应用设置页面
*/
private static void startAppSettings(Context context) {
Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
intent.setData(Uri.parse("package:" + context.getPackageName()));
context.startActivity(intent);
}
/**
* 验证权限是否都已经授权
*/
private static boolean verifyPermissions(int[] grantResults) {
// 如果请求被取消，则结果数组为空
if (grantResults.length <= 0)
return false;
// 循环判断每个权限是否被拒绝
for (int grantResult : grantResults) {
if (grantResult != PackageManager.PERMISSION_GRANTED) {
return false;
}
}
return true;
}
/**
* 获取权限列表中所有需要授权的权限
*
* @param context 上下文
* @param permissions 权限列表
* @return 需要授权的权限列表
*/
private static List<String> getDeniedPermissions(Context context, String... permissions) {
List<String> deniedPermissions = new ArrayList<>();
for (String permission : permissions) {
if (ContextCompat.checkSelfPermission(context, permission) == PackageManager.PERMISSION_DENIED) {
deniedPermissions.add(permission);
}
}
return deniedPermissions;
}
/**
* 检查所传递对象的正确性
*
* @param object 必须为 activity or fragment
*/
private static void checkCallingObjectSuitability(Object object) {
if (object == null) {
throw new NullPointerException("Activity or Fragment should not be null");
}
boolean isActivity = object instanceof Activity;
boolean isSupportFragment = object instanceof Fragment;
boolean isAppFragment = object instanceof android.app.Fragment;
if (!(isActivity || isSupportFragment || isAppFragment)) {
throw new IllegalArgumentException(
"Caller must be an Activity or a Fragment");
}
}
/**
* 检查所有的权限是否已经被授权
*
* @param permissions 权限列表
* @return 所有的权限是否已经被授权
*/
private static boolean checkPermissions(Context context, String... permissions) {
if (isOverMarshmallow()) {
for (String permission : permissions) {
if (ContextCompat.checkSelfPermission(context, permission) == PackageManager.PERMISSION_DENIED) {
return false;
}
}
}
return true;
}
/**
* 判断当前手机API版本是否 >= 6.0
*/
private static boolean isOverMarshmallow() {
return Build.VERSION.SDK_INT >= Build.VERSION_CODES.M;
}
public interface OnPermissionListener {
void onPermissionGranted();
void onPermissionDenied();
}
private static OnPermissionListener mOnPermissionListener;
}2、GetImagePath 的工具类
package com.example.hote.util;
import android.annotation.SuppressLint;
import android.content.ContentUris;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.provider.DocumentsContract;
import android.provider.MediaStore;
public class GetImagePath {
// 4.4以上 content://com.android.providers.media.documents/document/image:3952
// 4.4以下 content://media/external/images/media/3951
@SuppressLint("NewApi")
public static String getPath(final Context context, final Uri uri) {
final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
// DocumentProvider
if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
// ExternalStorageProvider
if (isExternalStorageDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
if ("primary".equalsIgnoreCase(type)) {
return Environment.getExternalStorageDirectory() + "/" + split[1];
}
}
// DownloadsProvider
else if (isDownloadsDocument(uri)) {
final String id = DocumentsContract.getDocumentId(uri);
final Uri contentUri = ContentUris.withAppendedId(
Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
return getDataColumn(context, contentUri, null, null);
}
// MediaProvider
else if (isMediaDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
Uri contentUri = null;
if ("image".equals(type)) {
contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
} else if ("video".equals(type)) {
contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
} else if ("audio".equals(type)) {
contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
}
final String selection = "_id=?";
final String[] selectionArgs = new String[]{
split[1]
};
return getDataColumn(context, contentUri, selection, selectionArgs);
}
}
// MediaStore (and general)
else if ("content".equalsIgnoreCase(uri.getScheme())) {
// Return the remote address
if (isGooglePhotosUri(uri))
return uri.getLastPathSegment();
return getDataColumn(context, uri, null, null);
}
// File
else if ("file".equalsIgnoreCase(uri.getScheme())) {
return uri.getPath();
}
return null;
}
//Android 4.4以下版本自动使用该方法
public static String getDataColumn(Context context, Uri uri, String selection,
String[] selectionArgs) {
Cursor cursor = null;
final String column = "_data";
final String[] projection = {
column
};
try {
cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,
null);
if (cursor != null && cursor.moveToFirst()) {
final int index = cursor.getColumnIndexOrThrow(column);
return cursor.getString(index);
}
} finally {
if (cursor != null)
cursor.close();
}
return null;
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is ExternalStorageProvider.
*/
public static boolean isExternalStorageDocument(Uri uri) {
return "com.android.externalstorage.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is DownloadsProvider.
*/
public static boolean isDownloadsDocument(Uri uri) {
return "com.android.providers.downloads.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is MediaProvider.
*/
public static boolean isMediaDocument(Uri uri) {
return "com.android.providers.media.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is Google Photos.
*/
public static boolean isGooglePhotosUri(Uri uri) {
return "com.google.android.apps.photos.content".equals(uri.getAuthority());
}
}第五步：Activity的代码
public class InfoActivity extends AppCompatActivity
{
private static final int IMAGE_REQUEST_CODE = 100;
private static final int IMAGE_REQUEST_CODE_GE7 = 101;
private static final int CAMERA_REQUEST_CODE = 104;
private static final int REQUEST_EXTERNAL_STORAGE_CODE = 200;
private File mGalleryFile;//存放图库选择是返回的图片
//相册的File对象
mGalleryFile=new File(path,”IMAGE_GALLERY_NAME.jpg”)
//*********核心代码***********
view.findViewById(R.id.tv_d_selectPhoto_pic)
.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//检查权限
String[] strPermissions=new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE //外部存储器写权限
};
MPermissionUtils.requestPermissionsResult(UserFragment.this, REQUEST_EXTERNAL_STORAGE_CODE, strPermissions, new MPermissionUtils.OnPermissionListener() {
//权限通过的回调
@Override
public void onPermissionGranted() {
//访问系统图库
Intent intent=new Intent(Intent.ACTION_GET_CONTENT);
intent.addCategory(Intent.CATEGORY_OPENABLE);//设置打开文件的模式读取
intent.setType("image/*");//告诉系统我要获取图片
if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.N){
//Android7.0及以上
Uri uriForFile= FileProvider.getUriForFile(mActivityContext,
"com.example.hote.fileprovider",mGalleryFile);
intent.putExtra(MediaStore.EXTRA_OUTPUT,uriForFile);
intent.addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
//启动页面，设置请求码
startActivityForResult(intent, IMAGE_REQUEST_CODE_GE7);
}else{
//Android7.0一下
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(mGalleryFile));
startActivityForResult(intent, IMAGE_REQUEST_CODE);
}
dialog.dismiss();//关闭dialog
}
//权限不通过的回调
@Override
public void onPermissionDenied() {
//判断是否有永久拒绝的权限
if (MPermissionUtils.hasAlwaysDeniedPermission(mActivityContext, strPermissions)) {
MPermissionUtils.showTipsDialog(mActivityContext);
} else {
Toast.makeText(mActivityContext, "您拒绝了应用需要的权限，将无法在图库中选择头像。请再试一次，并同意权限。"
, Toast.LENGTH_SHORT).show();
}
}
});
}
});
//权限请求的回调
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
MPermissionUtils.onRequestPermissionsResult(requestCode, permissions, grantResults);
}
//对uri进行获取
@Override
public void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == Activity.RESULT_OK && (data != null || requestCode == CAMERA_REQUEST_CODE)) {
switch (requestCode) {
case IMAGE_REQUEST_CODE://版本<7.0 图库返回
//获取图片的全路径
Uri uri = data.getData();
Log.e("ImagUri", uri.getPath());
//进行图像裁剪
sartPhotoZoom(uri);
break;
case IMAGE_REQUEST_CODE_GE7://版本>= 7.0 图库返回
//获取文件路径
String strPath = GetImagePath.getPath(mActivityContext, data.getData());
if (strPath!=null) {
File imgFile = new File(strPath);
//通过FileProvider创建一个content类型的Uri
Uri dataUri = FileProvider.getUriForFile(mActivityContext, "com.example.hote.fileprovider", imgFile);
Log.e("ImagUri", dataUri.getPath());
//进行图像裁剪
startPhotoZoom(dataUri);
} else {
Toast.makeText(mActivityContext, "选择图片失败", Toast.LENGTH_SHORT).show();
}
break;
case CAMERA_REQUEST_CODE://相机的返回
Uri inputUrl;
if (Build.VERSION.SDK_INT>=Build.VERSION_CODES.N){
//Android7.0及以上
//通过FileProvider创建一个content类型的Uri inputUrl=FileProvider.getUriForFile(mActivityContext,"com.example.hote.fileprovider",mCameraFile);
}else {
//Android7.0以下
inputUrl=Uri.fromFile(mCameraFile);
}
} else {
Toast.makeText(mActivityContext, "操作失败", Toast.LENGTH_SHORT).show();
}
}第六： 运行结果
到这里也算告一段落，现在我们已经拿到图片的uri。剩下的图片裁剪和上传，在这里：Android实现图片裁剪和上传
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