现在我已将文件推送到设备上了 当i Log.i（“imagePath”，imagePath）时，方法findPath becuz没有错误;当我选择那个图像并且我认为它是关于（text.setText（msg）;和image.setImageBitmap（imageData）;和当我删除text.setText（msg）和image.setImageBitmap（imageData）时，它返回路径图像;这不是错误。请检查一下＆amp;＆amp;检查我的布局
这是我在mainActivity中的代码
package com.example.gallerymagazine;
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.graphics.BitmapFactory;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
public class MainActivity extends Activity {
private static final int browse_image = 1;
private TextView text;
private Button browse;
private ImageView image;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TextView text = (TextView) findViewById(R.id.text);
ImageView image = (ImageView) findViewById(R.id.image);
Button browse = (Button) findViewById(R.id.browse_image_button);
browse.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent();
intent.setAction(Intent.ACTION_GET_CONTENT);
intent.setType("image/*");
startActivityForResult(Intent.createChooser(intent, "select app to pick image"),browse_image);
}
});
}
protected void onActivityResult(int requestCode, int resultCode, Intent returnedIntent){
super.onActivityResult(requestCode, resultCode, returnedIntent);
switch (requestCode){
case browse_image:
if(resultCode == RESULT_OK){
// เมือคลิกที่รูป ข้อมูลจะถูกส่งผ่านพารามิเตอร์ returnedIntent โดยมีผลลัพธ์เป็น URI(ฝช้ในการหาไฟล์พาด)
Uri imageUri = returnedIntent.getData();
String msg = "URL::"+imageUri+"\n";
// นำURI หาpath
String imagePath = findPath(imageUri);
msg += "Path::"+imagePath;
text.setText(msg);
// นำpath ไปดึงรูปมาแสดง
Bitmap imageData = BitmapFactory.decodeFile(imagePath);
image.setImageBitmap(imageData);
}
}
}
// method find path
private String findPath(Uri imageUri) {
// TODO Auto-generated method stub
String imagePath;
String[] columns = {MediaStore.Images.Media.DATA};
Cursor cursor = getContentResolver().query(imageUri, columns, null, null, null);
//จาก Gallery
if(cursor != null){
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
imagePath = cursor.getString(columnIndex);
}else{
imagePath = imageUri.getPath();
}
return imagePath;
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
这是我选择图像时的运行时错误
08-26 17:58:17.423: E/AndroidRuntime(11560): FATAL EXCEPTION: main
08-26 17:58:17.423: E/AndroidRuntime(11560): java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=-1, data=Intent { dat=content://media/external/images/media/12 }} to activity {com.example.gallerymagazine/com.example.gallerymagazine.MainActivity}: java.lang.NullPointerException
08-26 17:58:17.423: E/AndroidRuntime(11560): at android.app.ActivityThread.deliverResults(ActivityThread.java:3319)
08-26 17:58:17.423: E/AndroidRuntime(11560): at android.app.ActivityThread.handleSendResult(ActivityThread.java:3362)
08-26 17:58:17.423: E/AndroidRuntime(11560): at android.app.ActivityThread.access$1100(ActivityThread.java:141)
08-26 17:58:17.423: E/AndroidRuntime(11560): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1282)
08-26 17:58:17.423: E/AndroidRuntime(11560): at android.os.Handler.dispatchMessage(Handler.java:99)
08-26 17:58:17.423: E/AndroidRuntime(11560): at android.os.Looper.loop(Looper.java:137)
08-26 17:58:17.423: E/AndroidRuntime(11560): at android.app.ActivityThread.main(ActivityThread.java:5041)
08-26 17:58:17.423: E/AndroidRuntime(11560): at java.lang.reflect.Method.invokeNative(Native Method)
08-26 17:58:17.423: E/AndroidRuntime(11560): at java.lang.reflect.Method.invoke(Method.java:511)
08-26 17:58:17.423: E/AndroidRuntime(11560): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
08-26 17:58:17.423: E/AndroidRuntime(11560): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
08-26 17:58:17.423: E/AndroidRuntime(11560): at dalvik.system.NativeStart.main(Native Method)
08-26 17:58:17.423: E/AndroidRuntime(11560): Caused by: java.lang.NullPointerException
08-26 17:58:17.423: E/AndroidRuntime(11560): at com.example.gallerymagazine.MainActivity.onActivityResult(MainActivity.java:57)
08-26 17:58:17.423: E/AndroidRuntime(11560): at android.app.Activity.dispatchActivityResult(Activity.java:5293)
08-26 17:58:17.423: E/AndroidRuntime(11560): at android.app.ActivityThread.deliverResults(ActivityThread.java:3315)
08-26 17:58:17.423: E/AndroidRuntime(11560): ... 11 more
08-26 17:58:24.303: I/Process(11560): Sending signal. PID: 11560 SIG: 9
这是我的布局
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<Button
android:id="@+id/browse_image_button"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Browse Image"/>
<TextView
android:id="@+id/text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="16dp"
android:gravity="center"
/>
<ImageView
android:id="@+id/image"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:layout_gravity="center"
android:layout_marginTop="16dp"
android:scaleType="centerInside"
/>
请检查＆amp;谢谢
答案 0 :(得分：0)
试试这个：
protected void onActivityResult(int requestCode, int resultCode, Intent returnedIntent){
super.onActivityResult(requestCode, resultCode, returnedIntent);
switch (requestCode){
case browse_image:
if(resultCode != RESULT_CANCELED){
if(resultCode == RESULT_OK){
// เมือคลิกที่รูป ข้อมูลจะถูกส่งผ่านพารามิเตอร์ returnedIntent โดยมีผลลัพธ์เป็น URI(ฝช้ในการหาไฟล์พาด)
Uri imageUri = returnedIntent.getData();
String msg = "URL::"+imageUri+"\n";
// นำURI หาpath
String imagePath = findPath(imageUri);
msg += "Path::"+imagePath;
text.setText(msg);
// นำpath ไปดึงรูปมาแสดง
Bitmap imageData = BitmapFactory.decodeFile(imagePath);
image.setImageBitmap(imageData);
}
} else {
Log.e("Error", "error happened");
}
}
}
我将解释我做了什么，如果有效
<强>更新
更改Uri imageUri = returnedIntent.getData();
到Uri imageUri = data.getData();
答案 1 :(得分：0)
在你的onCreate方法中改变它：
TextView text = (TextView) findViewById(R.id.text);
ImageView image = (ImageView) findViewById(R.id.image);
Button browse = (Button) findViewById(R.id.browse_image_button);
到此：
text = (TextView) findViewById(R.id.text);
image = (ImageView) findViewById(R.id.image);
browse = (Button) findViewById(R.id.browse_image_button);
原因是当你这样做时
TextView text = (TextView) findViewById(R.id.text);
您正在定义一个其他方法无法访问的局部变量。所以当你尝试引用它时，你会得到一个空指针异常。
通过 user2045570
回答