前言，版本兼容问题主要是由于4.4以前和4.4以后的Uri的格式不同所造成的错误
1.拍照 和选择图片
①选择图片
intent = new Intent(Intent.ACTION_GET_CONTENT); intent.setType("image/*"); startActivityForResult(intent, GALLERY_REQUEST_CODE);
②拍照
intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); startActivityForResult(intent, CAMERA_REQUEST_CODE);
2.获取系统传来的值
标记符
private static int CAMERA_REQUEST_CODE = 1; private static int GALLERY_REQUEST_CODE = 2; private static int CROP_REQUEST_CODE = 3; @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { if (requestCode == CAMERA_REQUEST_CODE) { if (data == null) { return; } else { //拍照 Bundle extras = data.getExtras(); if (extras != null) { Bitmap bm = extras.getParcelable("data"); Uri uri = saveBitmap(bm); startImageZoom(uri); } } } else if (requestCode == GALLERY_REQUEST_CODE) { if (data == null) {//相册 return; } Uri uri; uri = data.getData(); Uri fileUri = convertUri(uri); startImageZoom(fileUri); } else if (requestCode == CROP_REQUEST_CODE) { if (data == null) { return; }//剪裁后的图片 Bundle extras = data.getExtras(); if (extras == null) { return; } Bitmap bm = extras.getParcelable("data"); ShowImageView(bm); } }
3.图片选取后 根据Url 转成流 并保存
private Uri convertUri(Uri uri) { InputStream is = null; try { is = getContentResolver().openInputStream(uri); Bitmap bitmap = BitmapFactory.decodeStream(is); is.close(); return saveBitmap(bitmap); } catch (FileNotFoundException e) { e.printStackTrace(); return null; } catch (IOException e) { e.printStackTrace(); return null; } }
4.保存图片 记得加权限
private Uri saveBitmap(Bitmap bm) { File tmpDir = new File(Environment.getExternalStorageDirectory() + "/xiaoxin"); if (!tmpDir.exists()) { tmpDir.mkdir(); } File img = new File(tmpDir.getAbsolutePath() + "love.png"); try { FileOutputStream fos = new FileOutputStream(img); bm.compress(Bitmap.CompressFormat.PNG, 85, fos); fos.flush(); fos.close(); Toast.makeText(MainActivity.this, "成功了", Toast.LENGTH_SHORT).show(); return Uri.fromFile(img); } catch (FileNotFoundException e) { Toast.makeText(MainActivity.this, "失敗了", Toast.LENGTH_SHORT).show(); e.printStackTrace(); return null; } catch (IOException e) { e.printStackTrace(); Toast.makeText(MainActivity.this, "失敗了", Toast.LENGTH_SHORT).show(); return null; } }
5.剪裁图片
/** * 剪裁图片 * * @param uri */ private void startImageZoom(Uri uri) { Intent intent = new Intent("com.android.camera.action.CROP"); intent.setDataAndType(uri, "image/*"); intent.putExtra("crop", "true"); intent.putExtra("aspectX", 1); intent.putExtra("aspectY", 1); intent.putExtra("outputX", 150); intent.putExtra("outputY", 150); intent.putExtra("return-data", true); startActivityForResult(intent, CROP_REQUEST_CODE); }
下面我们再来看一个实例：先是代码的部分，部分是从网路上摘录的，自己整理后当做工具类使用
配置文件：布局很简单，一个ImageButton和一个Button，点击都可以实现图像选择的功能，具体的实现根据大家在实际中用的效果而定
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AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.cogent.piccut" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="10" /> <application android:icon="@drawable/ic_launcher" android:label="@string/app_name" > <activity android:label="@string/app_name" android:name=".PicCutActivity" android:screenOrientation="portrait" > <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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Java代码：
package com.cogent.piccut; import java.io.File; import java.text.SimpleDateFormat; import java.util.Date; import android.app.Activity; import android.app.AlertDialog; import android.content.DialogInterface; import android.content.Intent; import android.graphics.Bitmap; import android.graphics.drawable.BitmapDrawable; import android.graphics.drawable.Drawable; 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.ImageButton; public class PicCutActivity extends Activity implements OnClickListener { private ImageButton img_btn; private Button btn; private static final int PHOTO_REQUEST_TAKEPHOTO = 1;// 拍照 private static final int PHOTO_REQUEST_GALLERY = 2;// 从相册中选择 private static final int PHOTO_REQUEST_CUT = 3;// 结果 // 创建一个以当前时间为名称的文件 File tempFile = new File(Environment.getExternalStorageDirectory(),getPhotoFileName()); /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); init(); } //初始化控件 private void init() { img_btn = (ImageButton) findViewById(R.id.img_btn); btn = (Button) findViewById(R.id.btn); //为ImageButton和Button添加监听事件 img_btn.setOnClickListener(this); btn.setOnClickListener(this); } //点击事件 @Override public void onClick(View v) { // TODO Auto-generated method stub switch (v.getId()) { case R.id.img_btn: showDialog(); break; case R.id.btn: showDialog(); break; } } //提示对话框方法 private void showDialog() { new AlertDialog.Builder(this) .setTitle("头像设置") .setPositiveButton("拍照", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub dialog.dismiss(); // 调用系统的拍照功能 Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); // 指定调用相机拍照后照片的储存路径 intent.putExtra(MediaStore.EXTRA_OUTPUT,Uri.fromFile(tempFile)); startActivityForResult(intent, PHOTO_REQUEST_TAKEPHOTO); } }) .setNegativeButton("相册", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub dialog.dismiss(); Intent intent = new Intent(Intent.ACTION_PICK, null); intent.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,"image/*"); startActivityForResult(intent, PHOTO_REQUEST_GALLERY); } }).show(); } @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { // TODO Auto-generated method stub switch (requestCode) { case PHOTO_REQUEST_TAKEPHOTO: startPhotoZoom(Uri.fromFile(tempFile), 150); break; case PHOTO_REQUEST_GALLERY: if (data != null) startPhotoZoom(data.getData(), 150); break; case PHOTO_REQUEST_CUT: if (data != null) setPicToView(data); break; } super.onActivityResult(requestCode, resultCode, data); } private void startPhotoZoom(Uri uri, int size) { Intent intent = new Intent("com.android.camera.action.CROP"); intent.setDataAndType(uri, "image/*"); // crop为true是设置在开启的intent中设置显示的view可以剪裁 intent.putExtra("crop", "true"); // aspectX aspectY 是宽高的比例 intent.putExtra("aspectX", 1); intent.putExtra("aspectY", 1); // outputX,outputY 是剪裁图片的宽高 intent.putExtra("outputX", size); intent.putExtra("outputY", size); intent.putExtra("return-data", true); startActivityForResult(intent, PHOTO_REQUEST_CUT); } //将进行剪裁后的图片显示到UI界面上 private void setPicToView(Intent picdata) { Bundle bundle = picdata.getExtras(); if (bundle != null) { Bitmap photo = bundle.getParcelable("data"); Drawable drawable = new BitmapDrawable(photo); img_btn.setBackgroundDrawable(drawable); } } // 使用系统当前日期加以调整作为照片的名称 private String getPhotoFileName() { Date date = new Date(System.currentTimeMillis()); SimpleDateFormat dateFormat = new SimpleDateFormat("'IMG'_yyyyMMdd_HHmmss"); return dateFormat.format(date) + ".jpg"; } }
心得总结：Androi系统内部自带了图片的剪裁功能，开发是只要调用即可，Intent的很多用法比较实用，但是太多了，需要用到的时候去查询或者平时多看看官方文档，很多代码看着简单但还是要实际自己去写更好些，理解的更深入一些。