我正在尝试一个在线教程，用于从图库或相机在 ImageView 中加载图像。图库部分工作正常，但相机部分强制关闭。从 onactvitiyresult 检索到的数据显示为空。
代码:
package com.example.cameragallerypro;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;
public class MainActivity extends Activity {
Uri selectedImageUri;
String selectedPath;
ImageView preview;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button b = (Button) findViewById(R.id.bGallery);
Button bCam= (Button) findViewById(R.id.bCamera);
preview = (ImageView) findViewById(R.id.preview);
bCam.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(cameraIntent, 100);
}
});
b.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
openGallery(10);
}
});
}
public void openGallery(int req_code){
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent,"Select file to upload "), req_code);
}
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK) {
if(data.getData() != null){
selectedImageUri = data.getData();
}else{
Log.d("selectedPath1 : ","Came here its null !");
Toast.makeText(getApplicationContext(), "failed to get Image!", 500).show();
}
if (requestCode == 100 && resultCode == RESULT_OK) {
Bitmap photo = (Bitmap) data.getExtras().get("data");
selectedPath = getPath(selectedImageUri);
preview.setImageURI(selectedImageUri);
Log.d("selectedPath1 : " ,selectedPath);
}
if (requestCode == 10)
{
selectedPath = getPath(selectedImageUri);
preview.setImageURI(selectedImageUri);
Log.d("selectedPath1 : " ,selectedPath);
}
}
}
public String getPath(Uri uri) {
String[] projection = { MediaStore.Images.Media.DATA };
Cursor cursor = managedQuery(uri, projection, null, null, null);
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
}
}
日志猫:
09-17 10:09:30.132: E/AndroidRuntime(7300): FATAL EXCEPTION: main
09-17 10:09:30.132: E/AndroidRuntime(7300): java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=100, result=-1, data=Intent { act=inline-data (has extras) }} to activity {com.example.cameragallerypro/com.example.cameragallerypro.MainActivity}: java.lang.NullPointerException
09-17 10:09:30.132: E/AndroidRuntime(7300): at android.app.ActivityThread.deliverResults(ActivityThread.java:2536)
09-17 10:09:30.132: E/AndroidRuntime(7300): at android.app.ActivityThread.handleSendResult(ActivityThread.java:2578)
09-17 10:09:30.132: E/AndroidRuntime(7300): at android.app.ActivityThread.access$2000(ActivityThread.java:117)
09-17 10:09:30.132: E/AndroidRuntime(7300): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:965)
09-17 10:09:30.132: E/AndroidRuntime(7300): at android.os.Handler.dispatchMessage(Handler.java:99)
09-17 10:09:30.132: E/AndroidRuntime(7300): at android.os.Looper.loop(Looper.java:130)
09-17 10:09:30.132: E/AndroidRuntime(7300): at android.app.ActivityThread.main(ActivityThread.java:3689)
09-17 10:09:30.132: E/AndroidRuntime(7300): at java.lang.reflect.Method.invokeNative(Native Method)
09-17 10:09:30.132: E/AndroidRuntime(7300): at java.lang.reflect.Method.invoke(Method.java:507)
09-17 10:09:30.132: E/AndroidRuntime(7300): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:842)
09-17 10:09:30.132: E/AndroidRuntime(7300): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
09-17 10:09:30.132: E/AndroidRuntime(7300): at dalvik.system.NativeStart.main(Native Method)
09-17 10:09:30.132: E/AndroidRuntime(7300): Caused by: java.lang.NullPointerException
09-17 10:09:30.132: E/AndroidRuntime(7300): at android.content.ContentResolver.acquireProvider(ContentResolver.java:743)
09-17 10:09:30.132: E/AndroidRuntime(7300): at android.content.ContentResolver.query(ContentResolver.java:256)
09-17 10:09:30.132: E/AndroidRuntime(7300): at android.app.Activity.managedQuery(Activity.java:1550)
09-17 10:09:30.132: E/AndroidRuntime(7300): at com.example.cameragallerypro.MainActivity.getPath(MainActivity.java:104)
09-17 10:09:30.132: E/AndroidRuntime(7300): at com.example.cameragallerypro.MainActivity.onActivityResult(MainActivity.java:79)
09-17 10:09:30.132: E/AndroidRuntime(7300): at android.app.Activity.dispatchActivityResult(Activity.java:3908)
09-17 10:09:30.132: E/AndroidRuntime(7300): at android.app.ActivityThread.deliverResults(ActivityThread.java:2532)
09-17 10:09:30.132: E/AndroidRuntime(7300): ... 11 more
如何修改代码以使相机部分正常工作？
最佳答案
bCam.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
from_camera();
}
});
b.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
from_gallery();
}
});
public void from_camera() {
Intent cameraIntent = new Intent(
android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(cameraIntent, 111);
}
public void from_gallery() {
Intent intent = new Intent(Intent.ACTION_PICK,
android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(intent, 222);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
if (resultCode == RESULT_OK && requestCode == 111) {
Bitmap photo = (Bitmap) data.getExtras().get("data");
preview.setImageBitmap(photo);
} else if (resultCode == RESULT_OK && requestCode == 222) {
Uri selectedImage = data.getData();
String[] filePathColumn = { MediaStore.Images.Media.DATA };
Cursor cursor = getContentResolver().query(selectedImage,
filePathColumn, null, null, null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
String picturePath = cursor.getString(columnIndex);
cursor.close();
preview.setImageBitmap(BitmapFactory.decodeFile(picturePath));
super.onActivityResult(requestCode, resultCode, data);
}
关于java - 尝试从 Android 中的图库或相机获取图像，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/25882479/