无法截取布局的截图

时间:2014-05-05 19:08:46

标签: java android android-layout

我试图在我的应用中截取一个布局的屏幕截图。但是当我按下屏幕截图按钮时,App会崩溃。

日志:

05-05 23:17:29.000: E/AndroidRuntime(21992): FATAL EXCEPTION: main
05-05 23:17:29.000: E/AndroidRuntime(21992): java.lang.NullPointerException
05-05 23:17:29.000: E/AndroidRuntime(21992):    at android.graphics.Bitmap.createBitmap(Bitmap.java:526)
05-05 23:17:29.000: E/AndroidRuntime(21992):    at com.tiktak.babyalbum.Helper$8.onClick(Helper.java:298)
05-05 23:17:29.000: E/AndroidRuntime(21992):    at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:185)
05-05 23:17:29.000: E/AndroidRuntime(21992):    at android.os.Handler.dispatchMessage(Handler.java:99)
05-05 23:17:29.000: E/AndroidRuntime(21992):    at android.os.Looper.loop(Looper.java:137)
05-05 23:17:29.000: E/AndroidRuntime(21992):    at android.app.ActivityThread.main(ActivityThread.java:5306)
05-05 23:17:29.000: E/AndroidRuntime(21992):    at java.lang.reflect.Method.invokeNative(Native Method)
05-05 23:17:29.000: E/AndroidRuntime(21992):    at java.lang.reflect.Method.invoke(Method.java:511)
05-05 23:17:29.000: E/AndroidRuntime(21992):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
05-05 23:17:29.000: E/AndroidRuntime(21992):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
05-05 23:17:29.000: E/AndroidRuntime(21992):    at dalvik.system.NativeStart.main(Native Method)

我使用Helper类来获得更干净的代码,这就是Helper Code Arround Line 298:

                View u = act.findViewById(id);
                u.setDrawingCacheEnabled(true);                                                
                LinearLayout z = (LinearLayout) act.findViewById(id);
                int totalHeight = z.getHeight();
                int totalWidth = z.getWidth();
                u.layout(0, 0, totalWidth, totalHeight);    
                u.buildDrawingCache(true);
298-->          Bitmap b = Bitmap.createBitmap(u.getDrawingCache()); 
                u.setDrawingCacheEnabled(false);
                String filePath = Environment.getExternalStorageDirectory()
                        + File.separator + st1;
                File myPath = new File(filePath);
                FileOutputStream fos = null;

这是一种奇怪的情况,因为如果我在高级手机(如三星s4)上进行测试就会崩溃,但是如果我在低级手机上测试它(就像HTC野火版那样)它可以正常工作细

任何想法?

编辑:根据Goran评论,我检查了以这种方式返回null的内容:

                View u = act.findViewById(id);               
                LinearLayout z = (LinearLayout) act.findViewById(id);
                u.setDrawingCacheEnabled(true);
                int totalHeight = z.getHeight();
                int totalWidth = z.getWidth();
                u.layout(0, 0, totalWidth, totalHeight);    
                u.buildDrawingCache(true);
                if (u.getDrawingCache() == null) {
                    Toast.makeText(act.getApplicationContext(), "DrawingCache is Null",
                            Toast.LENGTH_LONG).show();
                } else {
                    Bitmap b = Bitmap.createBitmap(u.getDrawingCache()); 
                    u.setDrawingCacheEnabled(false);
                    String filePath = Environment.getExternalStorageDirectory()
                            + File.separator + st1;
                    File myPath = new File(filePath);

并且在Wildfire S中,它有效,但在s4中我得到了#34; DrawingCatch为空"烤面包。

那么如何防止变为空?

1 个答案:

答案 0 :(得分:0)

感谢this回答我通过使用此代码解决了我的问题:

CustomView view = (CustomView) findViewById(R.id.customViewId);
Bitmap bitmap = Bitmap.createBitmap(view.getMeasuredWidth(), 
view.getMeasuredHeight(), Bitmap.Config.ARGB_8888); 
Canvas bitmapHolder = new Canvas(bitmap); 
view.draw(bitmapHolder);