参考注释郭霖老师的Android相机程序
16lz
2021-12-04
注释详细
1~main
package luyou.woyi.com.cameratest;import android.annotation.TargetApi;import android.content.ContentUris;import android.content.Intent;import android.database.Cursor;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.net.Uri;import android.os.Build;import android.os.Environment;import android.provider.DocumentsContract;import android.provider.MediaStore;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.ImageView;import android.widget.Toast;import java.io.File;import java.io.FileNotFoundException;import java.io.IOException;public class MainActivity extends AppCompatActivity { public static final int TAKE_PHOTO = 1; public static final int CROP_PHOTO = 2; public static final int CHOOSE_PHOTO = 3; private Button takephoto; private Button choosephoto; private ImageView picture; private Uri imageUri; @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); choosephoto = (Button) findViewById(R.id.choose_photo); /* * 实现监听器 * */ takephoto.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { /* * 创建File对象，实现拍照图片的存储 * */ File outputImage = new File(Environment.getExternalStorageDirectory(), "output_image.jpg"); /* * 初始化图片 * */ try { if (outputImage.exists()) { outputImage.delete(); } outputImage.createNewFile(); } catch (IOException e) { e.printStackTrace(); } /* * 将File对象转成Uri对象 * */ imageUri = Uri.fromFile(outputImage); /* * 构建隐式Intent，指定图片输出地址 * */ Intent intent = new Intent("android.media.action.IMAGE_CAPTURE"); intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri); /* * 启动相机，并向下一个活动传递参数 * */ startActivityForResult(intent, TAKE_PHOTO); } }); choosephoto.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent intent = new Intent("android.intent.action.GET_CONTENT"); intent.setType("image/*"); /* * 打开相册 * */ startActivityForResult(intent, CHOOSE_PHOTO); } }); } @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { switch (requestCode) { /* * 拍照成功返回结果，跳转到裁剪 * */ 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); /* * 启动剪裁程序 * */ startActivityForResult(intent, CROP_PHOTO); } break; /* * 裁剪结束，将.jpg解析成Bitmap显示出来 * */ case CROP_PHOTO: if (resultCode == RESULT_OK) { try { Bitmap bitmap = BitmapFactory.decodeStream( getContentResolver().openInputStream(imageUri)); picture.setImageBitmap(bitmap); //显示剪裁后的图片 } catch (FileNotFoundException e) { e.printStackTrace(); } } break; /* * 判断版本，选择处理图片方式 * */ case CHOOSE_PHOTO: if (resultCode == RESULT_OK) { if (Build.VERSION.SDK_INT >= 19) { /* * 4.4及以上版本 * */ handleImageOnKitKat(data); } else { /* * 4.4以下版本 * */ handleImageBeforeKitKat(data); } } break; default: break; } } /* * 4.4以上版本需要封装Uri * */ @TargetApi(19) private void handleImageOnKitKat(Intent data) { String imagePath = null; /* * 获取路径 * */ Uri uri = data.getData(); /* *Document类型Uri对document id处理 * */ if (DocumentsContract.isDocumentUri(this, uri)) { String docId = DocumentsContract.getDocumentId(uri); /* * 与Uri中Authority部分比较,media格式需进一步解析 * */ if ("com.android.providers.media.documents".equals( uri.getAuthority())) { String id = docId.split(":")[1]; String selection = MediaStore.Images.Media._ID + "=" + id; /* * 传入getImagePath获得真实路径 * */ imagePath = getImagePath( MediaStore.Images.Media.EXTERNAL_CONTENT_URI, selection); } else if ("com.android.providers.downloads.documents".equals( uri.getAuthority())) { /* * downloads格式获得路径 * */ Uri contentUri = ContentUris.withAppendedId( Uri.parse("content://downloads/public_downloads"), Long.valueOf(docId)); imagePath = getImagePath(contentUri, null); } } else if ("content".equalsIgnoreCase(uri.getScheme())) { /* * 普通处理 * */ imagePath = getImagePath(uri, null); } /* * 图片显示 * */ displayImage(imagePath); } /* * 4.4以下版本返回图片真实Uri，直接处理 * */ private void handleImageBeforeKitKat(Intent data) { Uri uri = data.getData(); String imagePath = getImagePath(uri, null); displayImage(imagePath); } /* * 获取图片路径 * */ private String getImagePath(Uri uri, String selection) { String path = null; Cursor cursor = getContentResolver().query(uri, null, selection, null, null); if (cursor != null) { /* * 定位第一行返回指定列名称 * */ if (cursor.moveToFirst()) { path = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA)); } /* * 释放资源 * */ cursor.close(); } return path; } /* * 打印图片 * */ private void displayImage(String imagePath) { if (imagePath != null) { /* * 将照片解析为Bitmap形式展现 * */ Bitmap bitmap = BitmapFactory.decodeFile(imagePath); picture.setImageBitmap(bitmap); } else { Toast.makeText(this, "failed to get image", Toast.LENGTH_SHORT).show(); } }}2~activity_layout.xml
<?xml version="1.0" encoding="utf-8"?> 没找到老师的源码地址，手打手打，若有不当还请指教
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