我正在开发一个应用程序，它首先将从相机拍摄的图像 uri 保存在 sqlite3 数据库中，然后将其取回以将其设置为 ImageView 。我在 vm 中遇到了众所周知的内存不足错误。我尝试了在其他各种问题中发现的各种方法，例如: 1)
So you
either need to encourage the imageView to recycle the previous bitmap - possibly with setImageView("") or get the bitmap from the URI and use setImageBitmap(android.graphics.Bitmap) instead; then you can dosetImageBitmap(null) and bitmap.recycle().
2)
((BitmapDrawable)imageView.getDrawable()).getBitmap().recycle();
3)
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
unbindDrawables(findViewById(R.id.showDataViewRoot));
System.gc();
}
奇怪的是，它们都不起作用，而且错误不断出现。主要是因为错误是在第一次尝试显示图像本身时出现的(所以我想没有机会回收)。搜索时我发现了以下链接: http://www.vogella.com/articles/AndroidCamera/article.html#example 从那里得到提示，我做了以下更改:
imageView.setImageBitmap(BitmapFactory.decodeStream(new FileInputStream(path)));
完成我的 ShowData.java 的修改代码(对之前的尝试进行了评论)。 fillImage()中设置图片的代码:
package org.dheeraj.imnci;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import android.app.Activity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.Spinner;
import android.widget.TableLayout;
import android.widget.TableRow;
import android.widget.TextView;
public class ShowData extends Activity {
private Spinner spinnerId;
private DbHelper dbHelper;
private SQLiteDatabase dbReader;
private Cursor cursor;
private ArrayList<String> idList;
private ArrayAdapter<String> adapter;
private String id;
private TableLayout dataTable;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.show_data);
dbHelper = new DbHelper(this);
spinnerId = (Spinner) findViewById(R.id.spinnerData);
dataTable = (TableLayout) findViewById(R.id.tableShowData);
fillSpinner();
}
private void fillData(String id) {
String tableNames[] = { "mother_reg", "anc_02", "anc_03", "anc_04",
"tt1", "tt2", "ttb", "abortions", "po", "pnc", "ifa" };
for (String table : tableNames) {
getDataFromTable(table, id);
}
}
private void getDataFromTable(String table, String id) {
// TODO Auto-generated method stub
getTableTitle(table);
getTableColumns(table, id);
}
private void getTableColumns(String table, String id) {
// TODO Auto-generated method stub
SQLiteDatabase dbReader;
Cursor cursor;
TableRow colRow;
TextView labelView;
TextView valueView;
String label;
String value;
dbReader = dbHelper.getReadableDatabase();
try {
if (table.equals("mother_reg"))
cursor = dbReader.query(table, null, "mid=" + id, null, null,
null, null, null);
else
cursor = dbReader.query(table, null, "ID=" + id, null, null,
null, null, null);
Log.d("getTableColumns", table);
if (cursor.moveToFirst()) {
do {
Log.d("in cursor", "" + cursor.getColumnCount());
for (int i = 0; i < cursor.getColumnCount(); i++) {
label = cursor.getColumnName(i);
value = cursor.getString(i);
labelView = new TextView(this);
valueView = new TextView(this);
colRow = new TableRow(this);
labelView.setText(label);
valueView.setText(value);
colRow.addView(labelView);
colRow.addView(valueView);
dataTable.addView(colRow);
}
} while (cursor.moveToNext());
}
cursor.close();
} finally {
if (dbReader != null)
dbReader.close();
}
}
private void getTableTitle(String table) {
// TODO Auto-generated method stub
TableRow tabRow;
TextView tv;
String title = table.replace('_', ' ').toUpperCase();
tabRow = new TableRow(this);
tv = new TextView(this);
tv.setText(title);
tv.setTextSize(20);
tabRow.addView(tv);
dataTable.addView(tabRow);
}
private void fillImage(String id) {
// TODO Auto-generated method stub
ImageView imageView;
boolean picFound;
SQLiteDatabase dbReader;
Cursor cursor;
String path = null;
imageView = (ImageView) findViewById(R.id.showDataImage);
picFound = false;
dbReader = dbHelper.getReadableDatabase();
try {
String tableName = "pictures";
String[] columns = { "mid", "uri" };
Log.d("id value", "" + id);
cursor = dbReader.query(tableName, columns, "mid=" + id, null,
null, null, null, null);
Log.d("gotCursor", "foundcursor");
if (cursor.moveToFirst()) {
Log.d("in cursor", "" + cursor.getColumnCount());
path = cursor.getString(cursor.getColumnIndex("uri"));
Log.d("show_data:imagepath", path);
if (path != null)
picFound = true;
// imgUri = Uri.parse(new File(path).toString());
/*
* bmpImage = BitmapFactory.decodeFile(path);
*
*
*
* scaledBmp = Bitmap.createScaledBitmap(bmpImage, 100, 150,
* true); bmpImage.recycle(); bmpImage = null;
*/
}
cursor.close();
} finally {
if (dbReader != null)
dbReader.close();
}
if (!picFound)
imageView.setImageResource(R.drawable.default_user);
else {
// Log.d("inimageview", imgUri.toString());
try {
imageView.setImageBitmap(BitmapFactory.decodeStream(new FileInputStream(path)));
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
// LayoutParams lv = new LayoutParams(200, 300);
// imgRow.setLayoutParams(lv);
}
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
unbindDrawables(findViewById(R.id.showDataViewRoot));
System.gc();
}
private void unbindDrawables(View view) {
if (view.getBackground() != null) {
view.getBackground().setCallback(null);
}
if (view instanceof ViewGroup && !(view instanceof AdapterView)) {
for (int i = 0; i < ((ViewGroup) view).getChildCount(); i++) {
unbindDrawables(((ViewGroup) view).getChildAt(i));
}
((ViewGroup) view).removeAllViews();
}
}
@Override
protected void onPause() {
// TODO Auto-generated method stub
super.onDestroy();
unbindDrawables(findViewById(R.id.showDataViewRoot));
System.gc();
}
void fillSpinner() {
dbReader = dbHelper.getReadableDatabase();
String columns[] = { "mid" };
try {
cursor = dbReader.query("mother_reg", columns, null, null, null,
null, "mid DESC");
if (cursor.moveToFirst()) {
idList = new ArrayList<String>();
do {
idList.add(cursor.getString(cursor.getColumnIndex("mid")));
} while (cursor.moveToNext());
cursor.close();
adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_spinner_item, idList);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinnerId.setAdapter(adapter);
spinnerId
.setOnItemSelectedListener(new OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> arg0,
View arg1, int arg2, long arg3) {
// TODO Auto-generated method stub
id = arg0.getItemAtPosition(arg2).toString();
// dataTable.removeAllViews();
unbindDrawables(dataTable);
fillImage(id);
fillData(id);
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
});
}
} finally {
if (dbReader != null)
dbReader.close();
}
}
}
我不明白它是如何工作的。与在 imageview.setimageuri(Uri.parse(path)) 中直接使用文件或它使用某种缓冲区相比，采用输入流是否会以某种方式减小大小？只是想知道出了什么问题。请告知是否需要有关我的应用程序代码的更多信息。但是这个奇怪的内存问题确实让我感到困惑，我真的对不同线程中提到的这么多方法感到困惑。 有关我的应用程序的更多信息: 目标 api: 1.6 中间 SDK 版本: 4
编辑 1:非常抱歉，但在使用 ShowData 进行了一些试验后，此方法也失败了。以下是 Logcat 的屏幕截图:
现在我真的很困惑。如何在我的 ImageView 中显示相机保存在 SD 卡中的简单图像？非常感谢您提供的任何帮助。
编辑 2:尝试对 fillimage View 方法进行更多更改:
try {
if(((BitmapDrawable)imageView.getDrawable())!=null)
((BitmapDrawable)imageView.getDrawable()).getBitmap().recycle();
imageView.setImageBitmap(BitmapFactory.decodeStream(new FileInputStream(path)));
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
除了出现以下错误外，它目前运行顺利:
我现在很想追根究底。请提供任何指导。对于这么多的编辑，我感到非常抱歉，但我想继续告知任何进一步的进展。
最佳答案
如果您想全屏显示单张图片，请使用 Intent.ACTION_VIEW 启动 Activity :
Intent i = new Intent(Intent.ACTION_VIEW);
i.setDataAndType(uri, "image/jpeg");
startActivity(i);
如果你想显示缩略图然后通过子采样减小这些图像的大小，只需将此选项添加到 BitmapFactory: http://developer.android.com/reference/android/graphics/BitmapFactory.Options.html#inSampleSize
编辑 1:
有好的文档:
http://developer.android.com/training/displaying-bitmaps/load-bitmap.html
编辑 2: 根据你的第二个问题:
Bitmap oldBitmap = ((BitmapDrawable) imageView.getDrawable()).getBitmap();
imageView.setImageDrawable(null); //this should help
oldBitmap.recycle();
imageView.setImageBitmap(newBitmap);
关于android - 在 android 中设置 imageview 位图时的奇怪行为，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/10976402/