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我有一个列表视图,显示来自我的数据库的不同数据。这很完美。但是我的列表中只能有 3 个项目,因为我在加载完整图像后内存不足。这是我现在正在工作的代码,但是当列表中超过三个列表项时,内存不足。

  String[] from = new String[] { "NAME", "DATE", "WEIGHT", "IMAGE_PATH"};      
  int[] to = new int[] { R.id.name, R.id.date, R.id.weight, R.id.list_image};
  contactAdapter = new SimpleCursorAdapter(
     Mylistview.this, R.layout.list_row, null, from, to);
  setListAdapter(contactAdapter);

我想要做的是将图像缩小到 72x72,然后再将它们加载到列表中。下面是一个没有按我想要的方式工作的代码,但它让你知道我想要什么:)

  list_image = (ImageView) findViewById(R.id.list_image);


  String[] from = new String[] { "NAME", "DATE", "WEIGHT", "IMAGE_PATH"};      
  int[] to = new int[] { R.id.name, R.id.date, R.id.weight};
  contactAdapter = new SimpleCursorAdapter(
     Mylistview.this, R.layout.list_row, null, from, to);
  setListAdapter(contactAdapter); 

 String icon = "IMAGE_PATH"

  Bitmap bmp = BitmapFactory.decodeStream(icon);        
  Bitmap bm = Bitmap.createScaledBitmap(bmp, 72, 72, false);
  list_image.setImageBitmap(bm);

我希望字符串图标从字符串数组中的数据库加载的“IMAGE_PATH”获取图像路径。

有没有办法做到这一点,还是我需要找到其他方法来用图像和小图标填充我的列表视图?也许当我拍照时,我应该将图像保存在两个地方。一张真实的图片和一个图标,并将图标路径放入数据库?

谢谢你

这是执行 Vishva Patel 帮助后的代码和错误代码。

       BitmapScaler scaler = null;
try {
    scaler = new BitmapScaler(new File("IMAGE_PATH"), 72);
} catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}
  list_image.setImageBitmap(scaler.getScaled());

 08-08 22:23:15.973: E/AndroidRuntime(2947): FATAL EXCEPTION: main
 08-08 22:23:15.973: E/AndroidRuntime(2947): java.lang.RuntimeException: Unable to  start activity   ComponentInfo{se.xflash.myapp/se.xflash.myapp.myapp}:     java.lang.RuntimeException: Unable to start activity  ComponentInfo{se.xflash.myapp/se.xflash.myapp.MyNames}:    java.lang.NullPointerException
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at  android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1968)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1993)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at android.app.ActivityThread.access$600(ActivityThread.java:127)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1159)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at android.os.Handler.dispatchMessage(Handler.java:99)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at android.os.Looper.loop(Looper.java:137)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at android.app.ActivityThread.main(ActivityThread.java:4507)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at java.lang.reflect.Method.invokeNative(Native Method)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at java.lang.reflect.Method.invoke(Method.java:511)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:790)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at dalvik.system.NativeStart.main(Native Method)
 08-08 22:23:15.973: E/AndroidRuntime(2947): Caused by: java.lang.RuntimeException: Unable to start activity ComponentInfo{se.xflash.myapp/se.xflash.myapp.MyNames}: java.lang.NullPointerException
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1968)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at android.app.ActivityThread.startActivityNow(ActivityThread.java:1809)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:135)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:347)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:682)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at android.widget.TabHost.setCurrentTab(TabHost.java:346)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at android.widget.TabHost.addTab(TabHost.java:236)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at se.xflash.myapp.myapp.onCreate(myapp.java:45)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at android.app.Activity.performCreate(Activity.java:4465)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1052)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at      android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1932)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    ... 11 more
 08-08 22:23:15.973: E/AndroidRuntime(2947): Caused by: java.lang.NullPointerException
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at se.xflash.myapp.BitmapScaler.<init>(BitmapScaler.java:42)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at se.xflash.myapp.MyNames.onCreate(MyNames.java:56)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at android.app.Activity.performCreate(Activity.java:4465)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1052)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1932)
 08-08 22:23:15.973: E/AndroidRuntime(2947):    ... 21 more
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1 回答 1

1

1.) 最简单的解决方案是使用这篇博文 BitmapScaler.java 中提到的类: http ://zerocredibility.wordpress.com/2011/01/27/android-bitmap-scaling/ ,它运行良好并解决了问题内存异常问题。您所要做的就是提供将图像保存为构造函数的参数的文件以及所需的缩放宽度(在您的情况下为 72)。这是您在特定情况下必须使用的代码:

BitmapScaler scaler = new BitmapScaler(new File("IMAGE_PATH"), 72);
list_image.setImageBitmap(scaler.getScaled());

2.) 是的,其中一种解决方案是在拍照时缩放位图并将其与原始图像一起保存为 icon-yourimagename.jpg(如果您需要拍摄的原始尺寸图像)

3.) 将 bm 分配给 list_image 后使用 bm.recycle() 以确保位图被垃圾收集并释放一些内存。这可能会修复内存错误。

于 2012-08-08T18:45:05.433 回答