我想问一下是否有办法将图像视图图像（图像从图库/摄像头捕获设置）转换为base64字符串？我尝试了多种方法，但我一直得到空指针异常。有没有人有解决这个问题的想法？我将我的base64字符串存储到windows azure中。我试过把这个方法放入。请注意我删除了我的api密钥和initmobileservice方法的网址，所以请理解并提前感谢
ImageView image;
Bitmap bitmap;
String baseUrl = "";
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.addramps);
GetLatLon();
InitMobileService();
pref = getApplicationContext().getSharedPreferences("Account", 0);
getActionBar().setDisplayHomeAsUpEnabled(true);
getActionBar().setHomeButtonEnabled(true);
description = (EditText) findViewById(R.id.tb_Description);
rbStairs = (RadioButton) findViewById(R.id.stairsRadioButton);
rbRamps = (RadioButton) findViewById(R.id.rampssRadioButton);
private void dataSave() {
if (rbStairs.isChecked() || rbRamps.isChecked()) {
//Error Here
Bitmap bitmap=BitmapFactory.decodeResource(getResources(), R.id.stairsRampsPhoto);
ByteArrayOutputStream stream=new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG, 90, stream);
byte[] image=stream.toByteArray();
final String base64 = Base64.encodeToString(image, 0);
final String lon = latlon.get(0), lat = latlon.get(1);
String userType = GetData("userType");
final String id = GetData("id");
if (userType.equals("caretaker")) {
mClient.getTable(careTakersProfile.class).where().field("id")
.eq(id)
.execute(new TableQueryCallback<careTakersProfile>() {
@Override
public void onCompleted(
List<careTakersProfile> result, int arg1,
Exception exception,
ServiceFilterResponse response) {
if (exception == null) {
mClient.getTable(dataAnalysis.class)
.insert(new dataAnalysis(
base64,
description.getText()
.toString(),
lat,
lon,
result.get(0).getNRIC(),
rbStairs.isChecked() ? "Stairs"
: "Ramps"),
new TableOperationCallback<dataAnalysis>() {
@Override
public void onCompleted(
dataAnalysis entity,
Exception exception,
ServiceFilterResponse response) {
if (exception == null) {
}
}
});
}
}
});
}
private void GetLatLon() {
final LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
latlon.add(location.getLongitude() + "");
latlon.add(location.getLatitude() + "");
}
@Override
public void onProviderDisabled(String arg0) {
// TODO Auto-generated method stub
}
@Override
public void onProviderEnabled(String arg0) {
// TODO Auto-generated method stub
}
@Override
public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
// TODO Auto-generated method stub
}
};
LocationManager lm = (LocationManager) getSystemService(getApplicationContext().LOCATION_SERVICE);
lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 5000, 0,
locationListener);
}
private void InitMobileService() {
try {
mClient = new MobileServiceClient(
"",
"", this);
} catch (MalformedURLException e) {
Log.d("ERROR", e.getMessage());
}
}
private void ClearData() {
Editor edit = pref.edit();
edit.clear();
edit.commit();
}
private void AddData(String key, String value) {
Editor edit = pref.edit();
edit.putString(key, value);
edit.commit();
}
private String GetData(String key) {
return pref.getString(key, "");
}
这是我的logcat输出
02-09 10:34:23.230: E/AndroidRuntime(434): FATAL EXCEPTION: main
02-09 10:34:23.230: E/AndroidRuntime(434): Process: com.example.androidjavaproject, PID: 434
02-09 10:34:23.230: E/AndroidRuntime(434): java.lang.NullPointerException
02-09 10:34:23.230: E/AndroidRuntime(434):
at com.example.androidjavaproject.AddrampsActivity.dataSave(AddrampsActivity.java:151)
02-09 10:34:23.230: E/AndroidRuntime(434):
at com.example.androidjavaproject.AddrampsActivity.access$0(AddrampsActivity.java:145)
02-09 10:34:23.230: E/AndroidRuntime(434):
at com.example.androidjavaproject.AddrampsActivity$1.onClick(AddrampsActivity.java:83)
02-09 10:34:23.230: E/AndroidRuntime(434):
at android.view.View.performClick(View.java:4445)
02-09 10:34:23.230: E/AndroidRuntime(434):
at android.view.View$PerformClick.run(View.java:18429)
02-09 10:34:23.230: E/AndroidRuntime(434):
at android.os.Handler.handleCallback(Handler.java:733)
02-09 10:34:23.230: E/AndroidRuntime(434):
at android.os.Handler.dispatchMessage(Handler.java:95)
02-09 10:34:23.230: E/AndroidRuntime(434): at android.os.Looper.loop(Looper.java:136)
02-09 10:34:23.230: E/AndroidRuntime(434):
at android.app.ActivityThread.main(ActivityThread.java:5087)
02-09 10:34:23.230: E/AndroidRuntime(434): at
java.lang.reflect.Method.invokeNative(Native Method)
02-09 10:34:23.230: E/AndroidRuntime(434): at
java.lang.reflect.Method.invoke(Method.java:515)
02-09 10:34:23.230: E/AndroidRuntime(434): at
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:781)
02-09 10:34:23.230: E/AndroidRuntime(434): at
com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
02-09 10:34:23.230: E/AndroidRuntime(434): at dalvik.system.NativeStart.main(Native
Method)
答案 0 :(得分：0)
很可能它没有得到图像可绘制。
替换
Bitmap bitmap=BitmapFactory.decodeResource(getResources(), R.id.stairsRampsPhoto);
与
Bitmap bitmap=BitmapFactory.decodeResource(getResources(), R.drawable.stairsRampsPhoto);
希望它有所帮助。