实现思维路径：
以进入相机拍照的思维路线为例子：
1.进入app
2.判断之前是否保存头像，如果有就显示历史图像 (下面代码中在getOldAvatar();方法中执行这个逻辑)
3.点击更换图像的Button或者布局，启动对话框(下面代码中在dialogueBox();方法执行这个逻辑)
4.系统版本判断授权方式(静态还是动态授权)，判断之前是否已经授权 （setPermissions(Permissions_CAMERA_KEY);这个方法执行授权逻辑）
5.如果是首次授权，就执行首次授权完成后马上运行的回调方法 onRequestPermissionsResult
5.判断完成不管是否是首次授权还是之前就是授权过了都要执行enterCamera();方法启动相机并且发送携带数据的请求
6.启动相机完成后，并且拍照完成退出相机，都要运行Intent返回数据请求回调方法onActivityResult。将传入的数据传入到cropPhoto(data.getData());方法里去执行图片剪裁。
7.在cropPhoto方法里将携带数据跳转到裁剪界面中裁剪图片，裁剪完成后又要回到onActivityResult回调方法里，执行裁剪完的数据回调工作。
8.在onActivityResult回调方法里，裁剪完的图片将运行setPicToView 方法保存图片。保存的图片将在下次启动activity时作为历史头像调用。
package com.example.lenovo.mydemoapp;
import android.app.Activity;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.os.StrictMode;
import android.provider.MediaStore;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;
import android.Manifest;
import com.example.lenovo.mydemoapp.myAppCompatActivity.MyAppCompatAcitivity;
import com.example.lenovo.mydemoapp.myLayout.TitleLayout;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class PersonalDataModification extends AppCompatActivity{
private static final String TAG = "PDM";
private TitleLayout mTitleLayout;
private TextView mTitleText;
private LinearLayout mPersonalDataModification_Avatar,mDialog_CameraButton,mDialog_GalleryButton;
private ImageView mPersonalDataModification_imageView_Avatar;
//得到外部存储根目录路径
private String mAvatarPath = Environment.getExternalStorageDirectory() + "/myAvatar/";
private String mAvatarName = "Avatar.jpg";
private Bitmap mBitmap;
/*
进入相册，相机，照片裁剪的key组
*/
private static final int ENTER_GALLERY = 1;
private static final int ENTER_CAMERA = 2;
private static final int ENTER_CROP_PHOTO = 3;
//需要在进入相机拍照或者相册选择图像中做区分。所以写了一个KEY来处理不同的Button
private static final int Permissions_GALLERY_KEY = 1;
private static final int Permissions_CAMERA_KEY = 2;
//需要的权限 注意请不要将数组写成 private String mPermissions[] = {"Manifest.permission.WRITE_EXTERNAL_STORAGE"};
//这样加了引号的是错误的
private String mPermissions[] = {Manifest.permission.WRITE_EXTERNAL_STORAGE,
Manifest.permission.READ_EXTERNAL_STORAGE,
Manifest.permission.CAMERA};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder();
StrictMode.setVmPolicy(builder.build());
builder.detectFileUriExposure();
setContentView(R.layout.activity_personal_data_modification);
// 设置标题栏
setTitle();
//显示历史头像
getOldAvatar();
// 添加对话框
dialogueBox();
}
/*
对话框
*/
public void dialogueBox(){
mPersonalDataModification_Avatar = (LinearLayout)findViewById(R.id.PersonalDataModification_Avatar);
mPersonalDataModification_Avatar.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//添加对话框
AlertDialog.Builder builder = new AlertDialog.Builder(PersonalDataModification.this);
//创建对话框 注意一定要这样写 在下面的dialog才能执行dismiss();方法
final AlertDialog dialog = builder.create();
View view = LayoutInflater.from(getBaseContext()).inflate(R.layout.dialog_layout,null,false);
//导入视图
dialog.setView(view);
mDialog_CameraButton = (LinearLayout)view.findViewById(R.id.PersonalDataModification_Dialog_CameraButton);
mDialog_GalleryButton = (LinearLayout)view.findViewById(R.id.PersonalDataModification_Dialog_GalleryButton);
//相机
mDialog_CameraButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//设置权限
setPermissions(Permissions_CAMERA_KEY);
//关闭对话框
dialog.dismiss();
}
});
//相册
mDialog_GalleryButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
setPermissions(Permissions_GALLERY_KEY);
dialog.dismiss();
}
});
//创建并且显示
dialog.show();
}
});
}
public void setPermissions(int mPermissions_KEY){
/*
要添加List原因是想判断数组里如果有个别已经授权的权限，就不需要再添加到List中。添加到List中的权限后续将转成数组去申请权限
*/
List<String> permissionsList = new ArrayList<>();
//判断系统版本
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
for (int i = 0; i < mPermissions.length; i++) {
//判断一个权限是否已经允许授权，如果没有授权就会将单个未授权的权限添加到List里面
if (ContextCompat.checkSelfPermission(this.getApplicationContext(), mPermissions[i]) != PackageManager.PERMISSION_GRANTED) {
permissionsList.add(mPermissions[i]);
}
}
//判断List不是空的，如果有内容就运行获取权限
if (!permissionsList.isEmpty()) {
String [] permissions = permissionsList.toArray(new String[permissionsList.size()]);
for (int j=0;j<permissions.length;j++){
Log.e(TAG,permissions[j]);
}
Log.e(TAG,"需要授权的权限有："+permissions.length+"条");
//执行授权的代码。此处执行后会弹窗授权
ActivityCompat.requestPermissions(this, permissions, mPermissions_KEY);
} else { //如果是空的说明全部权限都已经授权了，就不授权了,直接执行进入相机或者图库
switch (mPermissions_KEY) {
case Permissions_CAMERA_KEY:
enterCamera();
break;
case Permissions_GALLERY_KEY:
enterGallery();
break;
default:
break;
}
}
}else {
Toast.makeText(getBaseContext(), "6.0以下的版本无需授权", Toast.LENGTH_SHORT).show();
Log.e(TAG,"6.0以下的版本无需授权");
switch (mPermissions_KEY) {
case Permissions_CAMERA_KEY:
enterCamera();
break;
case Permissions_GALLERY_KEY:
enterGallery();
break;
default:
break;
}
}
}
/*
授权完成后马上会运行的回调方法，此处写入首次授权完成后，要运行的内容
*/
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode == Permissions_CAMERA_KEY) {
if (grantResults.length > 0) { //安全写法，如果小于0，肯定会出错了
for (int i = 0; i < grantResults.length; i++) {
if (grantResults[i] == PackageManager.PERMISSION_GRANTED) {
Log.e(TAG, "全部权限都成功授权进入相机");
enterCamera();
} else {
finish();
Toast.makeText(getBaseContext(), "授权失败", Toast.LENGTH_SHORT).show();
Log.e(TAG, "相机授权失败");
}
}
}
} else if (requestCode == Permissions_GALLERY_KEY) {
if (requestCode == Permissions_GALLERY_KEY) {
if (grantResults.length > 0) {
for (int i = 0; i < grantResults.length; i++) {
if (grantResults[i] == PackageManager.PERMISSION_GRANTED) {
Log.e(TAG, "全部权限都成功授权进入相册");
enterGallery();
} else {
finish();
Toast.makeText(getBaseContext(), "授权失败", Toast.LENGTH_SHORT).show();
Log.e(TAG, "相册授权失败");
}
}
}
}
}
}
/*
点击后进入相机
*/
public void enterCamera(){
//MediaStore 多媒体存储 ACTION行动 IMAGE 图片 CAPTURW捕获
Intent intentGallery = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
/* 多媒体存储，额外制造 从文件里获取路径(获取外部存储目录 图片名称head.jpg)
将图片设置名称并且保存到外部存储空间里
*/
intentGallery.putExtra(MediaStore.EXTRA_OUTPUT,
Uri.fromFile(new File(Environment.getExternalStorageDirectory(), mAvatarName)));
//跳转页面启动相册，携带数据请求码
startActivityForResult(intentGallery,ENTER_CAMERA);
}
/*
点击后进入相册
*/
public void enterGallery(){
Intent intentCamera = new Intent(Intent.ACTION_PICK,null);
//设置数据和类型 多媒体存储.图片.媒体.外部.内容.URI image/*图片格式
intentCamera.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,"image/*");
startActivityForResult(intentCamera, ENTER_GALLERY);
}
/*
从Intent中返回请求数据的方法，活动退出后运行这个方法
*/
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (requestCode){
/*
相册选中图片后的数据回调
*/
case ENTER_GALLERY:
if(resultCode == RESULT_OK){
cropPhoto(data.getData());
}
break;
/*
拍照完成后的数据回调
*/
case ENTER_CAMERA:
if (resultCode == RESULT_OK) {
File temp = new File(Environment.getExternalStorageDirectory() + "/"+mAvatarName);
cropPhoto(Uri.fromFile(temp));// 裁剪图片 cropPhoto 200行方法
}
break;
/*
裁剪完成后的数据回调
*/
case ENTER_CROP_PHOTO:
if (data.resolveActivity(getPackageManager())!=null) {//判断Intent是否为空
Bundle extras = data.getExtras();
mBitmap = extras.getParcelable("data");
if (mBitmap != null) {
setPicToView(mBitmap);// 保存在SD卡中
mPersonalDataModification_imageView_Avatar.setImageBitmap(mBitmap);// 用ImageButton显示出来
}
}
break;
default:
break;
}
super.onActivityResult(requestCode, resultCode, data);
}
/*
调用系统的裁剪功能，进入裁剪页面
*/
public void cropPhoto(Uri uri){
Intent intent = new Intent("com.android.camera.action.CROP");
intent.setDataAndType(uri,"image/*");
intent.putExtra("crop","ture");
intent.putExtra("aspectX", 1);
intent.putExtra("aspectY", 1);
// outputX outputY 是裁剪图片宽高
intent.putExtra("outputX", 250);
intent.putExtra("outputY", 250);
intent.putExtra("return-data", true);
Log.e(TAG,"头像裁剪");
startActivityForResult(intent, ENTER_CROP_PHOTO);
}
/*
显示默认头像或者历史设置的头像
*/
public void getOldAvatar(){
mPersonalDataModification_imageView_Avatar = (ImageView)findViewById(R.id.PersonalDataModification_imageView_Avatar);
//从文件存储里得到图片
Bitmap bt = BitmapFactory.decodeFile(mAvatarPath+mAvatarName);
//判断不是空头像
if (bt != null){
Drawable drawable = new BitmapDrawable(getResources(),bt);
//重新设置头像图片 注意这里使用的是setImageDrawable，不是setImageResource
mPersonalDataModification_imageView_Avatar.setImageDrawable(drawable);
Log.e(TAG,"使用历史头像");
}else {
//如果没有旧的头像就使用系统默认的
mPersonalDataModification_imageView_Avatar.setImageResource(R.drawable.ic_woman_default);
Log.e(TAG,"使用默认头像");
}
}
/*
保存到sd卡是为了下一次进入apk的时候直接读取图片，
*/
private void setPicToView(Bitmap mBitmap) {
String sdStatus = Environment.getExternalStorageState();
if (!sdStatus.equals(Environment.MEDIA_MOUNTED)) { // 检测sd是否可用
return;
}
try {
File dir = new File(mAvatarPath);
dir.mkdirs();// 创建文件夹
File file = new File(mAvatarPath, mAvatarName);
if (!file.exists()) {
file.createNewFile();
}
FileOutputStream b = new FileOutputStream(file);
mBitmap.compress(Bitmap.CompressFormat.JPEG, 100, b);// 把图片数据写入图片b
b.flush(); //刷新
b.close(); //关闭
}catch(IOException e){
e.printStackTrace();
}
/*
FileOutputStream b = null;
File file = new File(mAvatarPath);
file.mkdirs();// 创建文件夹
String fileName = mAvatarPath + mAvatarName;// 图片名字
try {
b = new FileOutputStream(fileName);
mBitmap.compress(Bitmap.CompressFormat.JPEG, 100, b);// 把图片数据写入图片b
} catch (FileNotFoundException e) {
e.printStackTrace();
} finally {
try {
b.flush(); //刷新
b.close(); //关闭
} catch (IOException e) {
e.printStackTrace();
}
}
*/
}
}