之前已经介绍了如何发布一条文字微博，接下来的两篇文章会介绍如何发送带图片的微博。今天先看如何调用照相或者Gallery来获取我们想要发送图片文件。
第一步，看需要申明的几个值
Java代码
- private String picPath;//文件路径
- private static final int PHOTO_WITH_CAMERA = 1010;// 拍摄照片
- private static final int PHOTO_WITH_DATA = 1020;// 从SD中得到照片
- private static final File PHOTO_DIR = new File(
- Environment.getExternalStorageDirectory() + "/DCIM/Camera");//拍摄照片存储的文件夹路劲
- private File capturefile;//拍摄的照片文件
private String picPath;//文件路径
private static final int PHOTO_WITH_CAMERA = 1010;// 拍摄照片
private static final int PHOTO_WITH_DATA = 1020;// 从SD中得到照片
private static final File PHOTO_DIR = new File(
Environment.getExternalStorageDirectory() + "/DCIM/Camera");//拍摄照片存储的文件夹路劲
private File capturefile;//拍摄的照片文件
第二步，选择获取图片方式的对话框实现
Java代码
- final Context dialogContext = new ContextThemeWrapper(context,
- android.R.style.Theme_Light);
- String[] choices;
- choices = new String[2];
- choices[0] = "相机拍摄"; // 拍照
- choices[1] = "本地相册"; // 从相册中选择
- final ListAdapter adapter = new ArrayAdapter<String>(dialogContext,
- android.R.layout.simple_list_item_1, choices);
- final AlertDialog.Builder builder = new AlertDialog.Builder(
- dialogContext);
- builder.setTitle("添加图片");
- builder.setSingleChoiceItems(adapter, -1,
- new DialogInterface.OnClickListener() {
- public void onClick(DialogInterface dialog, int which) {
- dialog.dismiss();
- switch (which) {
- case 0: {
- String status = Environment
- .getExternalStorageState();
- if (status.equals(Environment.MEDIA_MOUNTED)) {// 判断是否有SD卡
- Intent i = new Intent(
- MediaStore.ACTION_IMAGE_CAPTURE);
- capturefile = new File(PHOTO_DIR,
- getPhotoFileName());
- try {
- capturefile.createNewFile();
- i.putExtra(MediaStore.EXTRA_OUTPUT,
- Uri.fromFile(capturefile));//将拍摄的照片信息存到capturefile中
- } catch (IOException e) {
- // TODO Auto-generated catch block
- e.printStackTrace();
- }
- startActivityForResult(i, PHOTO_WITH_CAMERA);// 用户点击了从照相机获取
- } else {
- showToast("没有SD卡");
- }
- break;
- }
- case 1:// 从相册中去获取
- Intent intent = new Intent();
- intent.setType("image
- intent.setAction(Intent.ACTION_GET_CONTENT);
- startActivityForResult(intent, PHOTO_WITH_DATA);
- break;
- }
- }
- });
- builder.create().show();
- }
final Context dialogContext = new ContextThemeWrapper(context,
android.R.style.Theme_Light);
String[] choices;
choices = new String[2];
choices[0] = "相机拍摄"; // 拍照
choices[1] = "本地相册"; // 从相册中选择
final ListAdapter adapter = new ArrayAdapter<String>(dialogContext,
android.R.layout.simple_list_item_1, choices);
final AlertDialog.Builder builder = new AlertDialog.Builder(
dialogContext);
builder.setTitle("添加图片");
builder.setSingleChoiceItems(adapter, -1,
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
switch (which) {
case 0: {
String status = Environment
.getExternalStorageState();
if (status.equals(Environment.MEDIA_MOUNTED)) {// 判断是否有SD卡
Intent i = new Intent(
MediaStore.ACTION_IMAGE_CAPTURE);
capturefile = new File(PHOTO_DIR,
getPhotoFileName());
try {
capturefile.createNewFile();
i.putExtra(MediaStore.EXTRA_OUTPUT,
Uri.fromFile(capturefile));//将拍摄的照片信息存到capturefile中
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
startActivityForResult(i, PHOTO_WITH_CAMERA);// 用户点击了从照相机获取
} else {
showToast("没有SD卡");
}
break;
}
case 1:// 从相册中去获取
Intent intent = new Intent();
/* 开启Pictures画面Type设定为image */
intent.setType("image/*");
/* 使用Intent.ACTION_GET_CONTENT这个Action */
intent.setAction(Intent.ACTION_GET_CONTENT);
/* 取得相片后返回本画面 */
startActivityForResult(intent, PHOTO_WITH_DATA);
break;
}
}
});
builder.create().show();
}
Java代码
- private String getPhotoFileName() {
- Date date = new Date(System.currentTimeMillis());
- SimpleDateFormat dateFormat = new SimpleDateFormat(
- "'IMG'_yyyyMMdd_HHmmss");
- return dateFormat.format(date) + ".jpg";
- }
/*
* 通过相机回传图片的文件名
*/
private String getPhotoFileName() {
Date date = new Date(System.currentTimeMillis());
SimpleDateFormat dateFormat = new SimpleDateFormat(
"'IMG'_yyyyMMdd_HHmmss");
return dateFormat.format(date) + ".jpg";
}
再来看OnActivityResult
Java代码
- protected void onActivityResult(int requestCode, int resultCode, Intent data) {
- File file = null;
- Bitmap pic = null;
- if (resultCode == RESULT_OK) {
- switch (requestCode) {
- case PHOTO_WITH_CAMERA://获取拍摄的文件
- picPath = capturefile.getAbsolutePath();
- System.out.println(picPath);
- file = new File(picPath);
- pic = decodeFile(file);
- thumbimage.setImageBitmap(pic);
- System.out.println("++++++相机+++++");
- break;
- case PHOTO_WITH_DATA://获取从图库选择的文件
- Uri uri = data.getData();
- String scheme = uri.getScheme();
- if (scheme.equalsIgnoreCase("file")) {
- picPath = uri.getPath();
- System.out.println(picPath);
- file = new File(picPath);
- pic = decodeFile(file);
- thumbimage.setImageBitmap(pic);
- } else if (scheme.equalsIgnoreCase("content")) {
- Cursor cursor = getContentResolver().query(uri, null, null,
- null, null);
- cursor.moveToFirst();
- picPath = cursor.getString(1);
- file = new File(picPath);
- pic = decodeFile(file);
- thumbimage.setImageBitmap(pic);
- }
- break;
- }
- }
- super.onActivityResult(requestCode, resultCode, data);
- }
/*
* 选择图片的回传处理
*/
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
File file = null;
Bitmap pic = null;
if (resultCode == RESULT_OK) {
switch (requestCode) {
case PHOTO_WITH_CAMERA://获取拍摄的文件
picPath = capturefile.getAbsolutePath();
System.out.println(picPath);
file = new File(picPath);
pic = decodeFile(file);
thumbimage.setImageBitmap(pic);
System.out.println("++++++相机+++++");
break;
case PHOTO_WITH_DATA://获取从图库选择的文件
Uri uri = data.getData();
String scheme = uri.getScheme();
if (scheme.equalsIgnoreCase("file")) {
picPath = uri.getPath();
System.out.println(picPath);
file = new File(picPath);
pic = decodeFile(file);
thumbimage.setImageBitmap(pic);
} else if (scheme.equalsIgnoreCase("content")) {
Cursor cursor = getContentResolver().query(uri, null, null,
null, null);
cursor.moveToFirst();
picPath = cursor.getString(1);
file = new File(picPath);
pic = decodeFile(file);
thumbimage.setImageBitmap(pic);
}
break;
}
}
super.onActivityResult(requestCode, resultCode, data);
}
这里需要注意的是，从Gallery返回的内容，分为了两种情况。在模拟器上，我们可以发现返回的内容模式为"content”而从某些手机的操作例如MIUI，返回的scheme为"file"。同样，在MIUI上返回的照相内容依旧为file，但是可以通过通用方法，将照相的信息写入到我们制定的文件当中。也就是上面代码中的这两句
Java代码
- Intent i = new Intent(
- MediaStore.ACTION_IMAGE_CAPTURE);
- capturefile = new File(PHOTO_DIR,
- getPhotoFileName());
- try {
- capturefile.createNewFile();
- i.putExtra(MediaStore.EXTRA_OUTPUT,
- Uri.fromFile(capturefile));//将拍摄的照片信息存到capturefile中
- } catch (IOException e) {
- // TODO Auto-generated catch block
- e.printStackTrace();
- }
Intent i = new Intent(
MediaStore.ACTION_IMAGE_CAPTURE);
capturefile = new File(PHOTO_DIR,
getPhotoFileName());
try {
capturefile.createNewFile();
i.putExtra(MediaStore.EXTRA_OUTPUT,
Uri.fromFile(capturefile));//将拍摄的照片信息存到capturefile中
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
在之前的文章中，我们为发送微博页面设计了一个ImageView用来显示选取的照片。但是我们发现，如果不对返回的照片做处理，那么在第二次选择照片的时候系统会抛出内存溢出的错误。网上对这个问题的解释是，android只为每个程序分配8M的缓存，所以图片不经过压缩就会抛出异常。那么我们把图片压缩之后再显示在ImageView当中，压缩方法如下：
Java代码
- private Bitmap decodeFile(File f) {
- Bitmap b = null;
- try {
- // Decode image size
- BitmapFactory.Options o = new BitmapFactory.Options();
- o.inJustDecodeBounds = true;
- FileInputStream fis = new FileInputStream(f);
- BitmapFactory.decodeStream(fis, null, o);
- fis.close();
- int scale = 1;
- if (o.outHeight > 100 || o.outWidth > 100) {
- scale = (int) Math.pow(
- 2,
- (int) Math.round(Math.log(100 / (double) Math.max(
- o.outHeight, o.outWidth)) / Math.log(0.5)));
- }
- // Decode with inSampleSize
- BitmapFactory.Options o2 = new BitmapFactory.Options();
- o2.inSampleSize = scale;
- fis = new FileInputStream(f);
- b = BitmapFactory.decodeStream(fis, null, o2);
- fis.close();
- } catch (IOException e) {
- e.printStackTrace();
- }
- return b;
- }
/*
* 压缩图片，避免内存不足报错
*/
private Bitmap decodeFile(File f) {
Bitmap b = null;
try {
// Decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
FileInputStream fis = new FileInputStream(f);
BitmapFactory.decodeStream(fis, null, o);
fis.close();
int scale = 1;
if (o.outHeight > 100 || o.outWidth > 100) {
scale = (int) Math.pow(
2,
(int) Math.round(Math.log(100 / (double) Math.max(
o.outHeight, o.outWidth)) / Math.log(0.5)));
}
// Decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
fis = new FileInputStream(f);
b = BitmapFactory.decodeStream(fis, null, o2);
fis.close();
} catch (IOException e) {
e.printStackTrace();
}
return b;
}
至此，我们完成了对图片的选择，下一篇文章会通过新浪指定的方法，实现将图片上传到微博，也就是发送一条带图片的微博。
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Android：SNS客户端开发八：发送带图片的 ... | Android：SNS客户端开发六：发送一条文字 ...
- 2011-12-07 14:42
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- 评论(3)
- 分类:移动开发
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评论
3 楼 codeMoe 2012-03-21 还有个问题，我显示图片时，为什么都是将本来应该竖着显示的图片，变为横着显示，压缩后照片很多锯齿 2 楼 codeMoe 2012-03-21 codeMoe 写道 ntent i = new Intent(
MediaStore.ACTION_IMAGE_CAPTURE);
capturefile = new File(PHOTO_DIR,
getPhotoFileName());
try {
capturefile.createNewFile();
i.putExtra(MediaStore.EXTRA_OUTPUT,
Uri.fromFile(capturefile));//将拍摄的照片信息存到capturefile中
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
请问这段是在什么时候调用
额。。不好意思，是我没仔细看，就在那拍照哪里调用 1 楼 codeMoe 2012-03-21 ntent i = new Intent(
MediaStore.ACTION_IMAGE_CAPTURE);
capturefile = new File(PHOTO_DIR,
getPhotoFileName());
try {
capturefile.createNewFile();
i.putExtra(MediaStore.EXTRA_OUTPUT,
Uri.fromFile(capturefile));//将拍摄的照片信息存到capturefile中
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
请问这段是在什么时候调用
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转自：http://river418.iteye.com/blog/1295836