問題描述
在活動之間使用意圖錯誤 (using intents between activities error)
使用我得到的 logcat (who=null) 中的意圖從視頻捕獲活動返回時出現運行時錯誤，並且應用程序在該點崩潰（從視頻捕獲活動返回到主要活動時。我的問題是當我在 Genymotion 模擬器上運行應用程序時不會發生這種情況，但是當我在手機上安裝它時，應用程序停止並顯示消息（不幸的是應用程序已停止工作）我試圖通過使用答案來解決我的代碼中的問題以下鏈接
通過添加語句：
setResult(RESULT_OK, intent2); //addition
它就像我之前提到的那樣工作，但只有當應用程序在模擬器而不是手機上運行時
這是我的代碼：
package com.example.israajaradat.vlc;
import android.content.Intent;
import android.graphics.Color;
import android.media.MediaMetadataRetriever;
import android.net.Uri;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import java.io.File;
public class Activity1 extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_1);}
//‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑
//Button btnReadyToGo= (Button)findViewById(R.id.btnReady);
public void onButtonClick(View view1){ //if button is clicked
//TextView label3=(TextView)findViewById(R.id.lbl3);
//label3.setTextColor(Color.CYAN); //change color
//‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑invoke the video recording built in interface‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑
String CAPTURE_TITLE="MyVideo89.3gp";
// Specified the desired location here
File myfile = new File(Environment.getExternalStorageDirectory() + "/DCIM/", CAPTURE_TITLE);
Uri outputFileUri = Uri.fromFile( myfile );
Intent intent2 = new Intent(android.provider.MediaStore.ACTION_VIDEO_CAPTURE);
setResult(RESULT_OK, intent2); //addition
intent2.putExtra(android.provider.MediaStore.EXTRA_OUTPUT, outputFileUri);
startActivityForResult(intent2, REQUEST_VIDEO_CAPTURED);
//‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑
//‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑
} //end of OnButtonclick funciton
//‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑
// private static final int VIDEO_CAPTURE = 101;
final static int REQUEST_VIDEO_CAPTURED = 1;
// Intent intent1 = new Intent(MediaStore.ACTION_VIDEO_CAPTURE);
// startActivityForResult(intent1, VIDEO_CAPTURE);
//‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑
//‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑after recording finishes‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
Uri uri2=data.getData();
// if (data == null) return;
if(resultCode==RESULT_OK && requestCode==1){
// if (requestCode == REQUEST_VIDEO_CAPTURED) {
// if (resultCode == RESULT_OK) {
// Toast.makeText(this, "Video saved to:\n" + uri2, Toast.LENGTH_LONG).show();
Toast.makeText(this, uri2.getPath() , Toast.LENGTH_LONG).show();
} else if (resultCode == RESULT_CANCELED) {
Toast.makeText(this, "Video recording cancelled.", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(this, "Failed to record video", Toast.LENGTH_LONG).show();
}
//}
//‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑getting video length‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑
/* MediaMetadataRetriever retriever = new MediaMetadataRetriever();
retriever.setDataSource(Environment.getExternalStorageDirectory() + "/DCIM/"+ "MyVideo89.3gp");
String time = retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION);
long timeInmillisec = Long.parseLong( time );
long duration = timeInmillisec / 1000;*/
//‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_activity1, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
這是來自 logcat：
11‑21 07:38:57.317 1737‑1737/com.example.israajaradat.vlc E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.israajaradat.vlc, PID: 1737
java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=0, data=null} to activity {com.example.israajaradat.vlc/com.example.israajaradat.vlc.Activity1}: java.lang.NullPointerException
at android.app.ActivityThread.deliverResults(ActivityThread.java:3351)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:3394)
at android.app.ActivityThread.access$1300(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1244)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5001)
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:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.example.israajaradat.vlc.Activity1.onActivityResult(Activity1.java:65)
at android.app.Activity.dispatchActivityResult(Activity.java:5423)
at android.app.ActivityThread.deliverResults(ActivityThread.java:3347)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:3394)
at android.app.ActivityThread.access$1300(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1244)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5001)
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:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
參考解法
方法 1:
Did you try using The format Intent intent = new Intent(mainactivity.this, new activity.class); Startactivity(intent);
方法 2:
You can try this...
private String videoPath = "";
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if(resultCode==RESULT_OK)
{
Uri vid = data.getData();
videoPath = getRealPathFromURI(vid);
} else if (resultCode == RESULT_CANCELED) {
Toast.makeText(this, "Video recording cancelled.", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(this, "Failed to record video", Toast.LENGTH_LONG).show();
}
}
public String getRealPathFromURI(Uri contentUri) {
String[] proj = { MediaStore.Images.Media.DATA };
Cursor cursor = managedQuery(contentUri, proj, null, null, null);
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
}
(by hj E、aghil mohammed、SRB Bans)