我尝试过堆栈溢出的答案，但没有工作，得到空指针。
我尝试过的事情：
MainActivity.java：
public class MainActivity extends AppCompatActivity {
ImageView ivSelectCardLogo;
Button btnNext;
private static int RESULT_LOAD_IMG = 1;
String imgDecodableString;
Bitmap bmp;
ByteArrayOutputStream stream;
byte[] byteArray;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnNext=(Button)findViewById(R.id.btnNext);
btnNext.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
bmp = BitmapFactory.decodeResource(getResources(), R.drawable.idymlogo);
stream = new ByteArrayOutputStream();
bmp.compress(Bitmap.CompressFormat.PNG, 100, stream);
byteArray = stream.toByteArray();
Intent intent = new Intent(getApplicationContext(), NewActivity.class);
intent.putExtra("picture", byteArray);
startActivity(intent);
}
});
ivSelectCardLogo=(ImageView)findViewById(R.id.ivSelectCardLogo);
ivSelectCardLogo.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
loadImagefromGallery(v);
}
});
}
public void loadImagefromGallery(View view) {
// Create intent to Open Image applications like Gallery, Google Photos
Intent galleryIntent = new Intent(Intent.ACTION_PICK,
android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
// Start the Intent
startActivityForResult(galleryIntent, RESULT_LOAD_IMG);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
try {
// When an Image is picked
if (requestCode == RESULT_LOAD_IMG && resultCode == RESULT_OK
&& null != data) {
// Get the Image from data
Uri selectedImage = data.getData();
String[] filePathColumn = { MediaStore.Images.Media.DATA };
// Get the cursor
Cursor cursor = getContentResolver().query(selectedImage,
filePathColumn, null, null, null);
// Move to first row
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
imgDecodableString = cursor.getString(columnIndex);
cursor.close();
// ivSelectCardLogo=(ImageView)findViewById(R.id.ivSelectCardLogo);
// Set the Image in ImageView after decoding the String
ivSelectCardLogo.setImageBitmap(BitmapFactory
.decodeFile(imgDecodableString));
} else {
Toast.makeText(this, "You haven't picked Image",
Toast.LENGTH_LONG).show();
}
} catch (Exception e) {
Toast.makeText(this, "Something went wrong", Toast.LENGTH_LONG)
.show();
}
}
}
NextActivity：
public class NewActivity extends AppCompatActivity {
ImageView ivCardOneLogo;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_new);
Bundle extras = getIntent().getExtras();
byte[] byteArray = extras.getByteArray("picture");
Bitmap bmp = BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length);
ivCardOneLogo = (ImageView) findViewById(R.id.ivCardOneLogo);
ivCardOneLogo.setImageBitmap(bmp);
}
}
logcat的：
FATAL EXCEPTION: main
Process: com.imagetransfer, PID: 19845
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.imagetransfer/com.imagetransfer.NewActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.imagetransfer.NewActivity.onCreate(NewActivity.java:25)
at android.app.Activity.performCreate(Activity.java:5231)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
我只想将从图库中获取的图像传递到另一个活动，并在下一个活动中在图像视图中设置该图像。简单，但没有适当的演示.. 尝试几乎所有的堆栈问题，但没有一个适合我 .. 建议是热烈欢迎..