在此知识点上笔者也是花了大量的时间,由于android版本的更新,android4.4和android4.3在OnActivityResult中返回的uri是完全不同的,所以也造成了笔者的学习资料中的demo不能正常运行的情况,也是纠结了大半天。
但是在此博文中也是对其中细节不做介绍了,还是把正确的代码展示给大家把。
主界面:
选择相册中的照片:
选择照片后的裁剪界面:
完成后效果:
MainActivity:
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.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.ImageView; import android.widget.Toast; public class MainActivity extends Activity { public static final int CUT_PICTURE = 1; public static final int SHOW_PICTURE = 2; private Button takePhoto; private Button chooseFromAlbum; 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); chooseFromAlbum = (Button) findViewById(R.id.choose_from_album); 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 //将此图片存储于SD卡的根目录下 File outputImage = new File(Environment.getExternalStorageDirectory(), "output_image.jpg"); try { if (outputImage.exists()) { outputImage.delete(); } outputImage.createNewFile(); } catch (IOException e) { e.printStackTrace(); } //将File对象转换成Uri对象 //Uri表标识着图片的地址 imageUri = Uri.fromFile(outputImage); //隐式调用照相机程序 Intent intent = new Intent("android.media.action.IMAGE_CAPTURE"); //拍下的照片会被输出到output_image.jpg中去 intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri); //此处是使用的startActivityForResult() //因此在拍照完后悔有结果返回到onActivityResult()中去,返回值即为<span style="font-size: 13.3333px; font-family: Arial, Helvetica, sans-serif;">CUT_PICTURE</span> //onActivityResult()中主要是实现图片裁剪 startActivityForResult(intent, CUT_PICTURE); } }); chooseFromAlbum.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { 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(Intent.ACTION_PICK,null); //此处调用了图片选择器 //如果直接写intent.setDataAndType("image/*"); //调用的是系统图库 intent.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, "image/*"); intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri); startActivityForResult(intent, CUT_PICTURE); } }); } @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { switch (requestCode) { case CUT_PICTURE: if (resultCode == RESULT_OK) { //此处启动裁剪程序 Intent intent = new Intent("com.android.camera.action.CROP"); //此处注释掉的部分是针对android 4.4路径修改的一个测试 //有兴趣的读者可以自己调试看看 // String text=data.getData().toString(); // Toast.makeText(MainActivity.this, text, Toast.LENGTH_SHORT).show(); intent.setDataAndType(data.getData(), "image/*"); intent.putExtra("scale", true); intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri); startActivityForResult(intent, SHOW_PICTURE); } break; case SHOW_PICTURE: if (resultCode == RESULT_OK) { try { //将output_image.jpg对象解析成Bitmap对象,然后设置到ImageView中显示出来 Bitmap bitmap = BitmapFactory.decodeStream(getContentResolver() .openInputStream(imageUri)); picture.setImageBitmap(bitmap); } catch (FileNotFoundException e) { e.printStackTrace(); } } break; default: break; } } }
<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="Take Photo" /> <Button android:id="@+id/choose_from_album" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="Choose From Album" /> <ImageView android:id="@+id/picture" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_horizontal" /> </LinearLayout>
<?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="14" android:targetSdkVersion="17" /> <application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name="com.example.choosepictest.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>