我需要将大视图说（宽度和高度为1280x1760）转换为Bitmap并将图像保存到sdcard.But当我创建大于1280x1400的视图时，我的应用程序抛出一个异常wnen createBitmap（view.getDrawingCache（）被叫。我正在使用10英寸三星标签。 图像像素是否依赖于标签像素 这是我的代码
View view2=LayoutInflater.from(getApplicationContext()).inflate(R.layout.sample, null);
LinearLayout view=new LinearLayout(getApplicationContext());
view.setBackgroundColor(Color.GRAY);
view.setOrientation(LinearLayout.VERTICAL);
view.addView(view2,new LayoutParams(1280,1760));
view.setDrawingCacheEnabled(true);
view.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),
MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());
view.buildDrawingCache(true);
try{
Bitmap bitmap = Bitmap.createBitmap(view.getDrawingCache());
//Bitmap bitmap = Bitmap.createScaledBitmap(view.getDrawingCache(), 1280, 1200, true);
//setContentView(view);
String path = Environment.getExternalStorageDirectory()+"/Pictures";
File image = new File(path, "Image7.jpg");
// Encode the file as a PNG image.
FileOutputStream outStream=null;
outStream = new FileOutputStream(image);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, outStream);
outStream.flush();
outStream.close();
setContentView(view);
} catch (Exception e) {
Toast.makeText(getBaseContext(), e.getMessage(), 10).show();
}
和sample.xml布局是
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ImageView
android:id="@+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/ic_launcher" />
<TextView
android:id="@+id/textView1"
android:layout_width="match_parent"
android:layout_height="300px"
android:text="TextView"
android:background="#ffff00"/>
<Button android:layout_weight="1"
android:id="@+id/button1" android:background="#ff00ff"
android:layout_width="match_parent"
android:layout_height="0dp"
android:text="Button" />
<Button android:layout_weight="1" android:background="#ff0000"
android:id="@+id/button2"
android:layout_width="match_parent"
android:layout_height="0dp"
android:text="Button" />
</LinearLayout>
这是LOGCAT
01-21 14:26:50.381: E/AndroidRuntime(1611): FATAL EXCEPTION: main
01-21 14:26:50.381: E/AndroidRuntime(1611): java.lang.NullPointerException
01-21 14:26:50.381: E/AndroidRuntime(1611): at android.graphics.Bitmap.createBitmap(Bitmap.java:455)
01-21 14:26:50.381: E/AndroidRuntime(1611): at com.hunterlab.essentials.view2image.View2ImageActivity$1.Check(View2ImageActivity.java:196)
01-21 14:26:50.381: E/AndroidRuntime(1611): at com.hunterlab.essentials.view2image.View2ImageActivity$1.onClick(View2ImageActivity.java:79)
01-21 14:26:50.381: E/AndroidRuntime(1611): at android.view.View.performClick(View.java:3110)
01-21 14:26:50.381: E/AndroidRuntime(1611): at android.view.View$PerformClick.run(View.java:11928)
01-21 14:26:50.381: E/AndroidRuntime(1611): at android.os.Handler.handleCallback(Handler.java:587)
01-21 14:26:50.381: E/AndroidRuntime(1611): at android.os.Handler.dispatchMessage(Handler.java:92)
01-21 14:26:50.381: E/AndroidRuntime(1611): at android.os.Looper.loop(Looper.java:132)
01-21 14:26:50.381: E/AndroidRuntime(1611): at android.app.ActivityThread.main(ActivityThread.java:4025)
01-21 14:26:50.381: E/AndroidRuntime(1611): at java.lang.reflect.Method.invokeNative(Native Method)
01-21 14:26:50.381: E/AndroidRuntime(1611): at java.lang.reflect.Method.invoke(Method.java:491)
01-21 14:26:50.381: E/AndroidRuntime(1611): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
01-21 14:26:50.381: E/AndroidRuntime(1611): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
01-21 14:26:50.381: E/AndroidRuntime(1611): at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：0)
尝试以下操作（即使视图已禁用其绘图缓存，也可以使用）：
int width = view.getWidth();
int height = view.getHeight();
Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
view.draw(canvas);
// The view has now drawn to `bitmap`
答案 1 :(得分：0)
嗨，请看一下这段代码。
public static Bitmap new_decode(File f) {
// decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
o.inDither = false; // Disable Dithering mode
o.inPurgeable = true; // Tell to gc that whether it needs free memory,
// the Bitmap can be cleared
o.inInputShareable = true; // Which kind of reference will be used to
// recover the Bitmap data after being
// clear, when it will be used in the future
try {
BitmapFactory.decodeStream(new FileInputStream(f), null, o);
} catch (FileNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
// Find the correct scale value. It should be the power of 2.
final int REQUIRED_SIZE = 300;
int width_tmp = o.outWidth, height_tmp = o.outHeight;
int scale = 1;
while (true) {
if (width_tmp / 1.5 < REQUIRED_SIZE && height_tmp / 1.5 < REQUIRED_SIZE)
break;
width_tmp /= 1.5;
height_tmp /= 1.5;
scale *= 1.5;
}
// decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
// o2.inSampleSize=scale;
o.inDither = false; // Disable Dithering mode
o.inPurgeable = true; // Tell to gc that whether it needs free memory,
// the Bitmap can be cleared
o.inInputShareable = true; // Which kind of reference will be used to
// recover the Bitmap data after being
// clear, when it will be used in the future
// return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
try {
// return BitmapFactory.decodeStream(new FileInputStream(f), null,
// null);
Bitmap bitmap= BitmapFactory.decodeStream(new FileInputStream(f), null, null);
System.out.println(" IW " + width_tmp);
System.out.println("IHH " + height_tmp);
// int iW = width_tmp;
// int iH = height_tmp;
int iW = Talk_Library.screen_width;
int iH = Talk_Library.screen_height;
return Bitmap.createScaledBitmap(bitmap, iW, iH, true);
} catch (OutOfMemoryError e) {
// TODO: handle exception
e.printStackTrace();
// clearCache();
// System.out.println("bitmap creating success");
System.gc();
return null;
// System.runFinalization();
// Runtime.getRuntime().gc();
// System.gc();
// decodeFile(f);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return null;
}
}