【发布时间】:2014-11-04 15:26:43
【问题描述】:
我有一个使用 this 库的示例条形码扫描仪应用程序。
onActivityResult 不会更新 textView 或 editText。
我做了一些搜索,发现这是一个常见问题。
onActivityResult 我得到了我通过的值,我可以记录并敬酒该值,但不适用于 setText() 方法。
编辑:我正在使用片段。
片段 A 是按钮、编辑和文本视图所在的位置,片段 B 是条形码扫描仪,我使用 popBackStack() 返回片段 A(从片段 B 接收数据);
这是我的代码:
package com.gilbert.apptastic.barcodefragment;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.content.Intent;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
public static final int DIALOG_FRAGMENT = 1;
public TextView textView;
public TextView textView2;
public TextView textView3;
public TextView textView4;
public EditText editText;
public Button button;
public String barcode;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
textView = (TextView)rootView.findViewById(R.id.textView);
textView2 = (TextView)rootView.findViewById(R.id.textView2);
textView3 = (TextView)rootView.findViewById(R.id.textView3);
textView4 = (TextView)rootView.findViewById(R.id.textView4);
editText = (EditText)rootView.findViewById(R.id.editText);
button = (Button)rootView.findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
scanBarcode();
}
});
// setText();
return rootView;
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if(requestCode == DIALOG_FRAGMENT && resultCode == Activity.RESULT_OK) {
// System.out.println("ok");
barcode = data.getExtras().getString("barcode");
// edit_barcode.setText(value);
setText();
Toast.makeText(getActivity(), barcode, Toast.LENGTH_SHORT).show();
// System.out.println(barcode);
// edit_barcode.setText(barcode);
}
}
public void setText() {
System.out.println(barcode);
textView.setText(barcode);
textView2.setText(barcode);
textView3.setText(barcode);
textView4.setText(barcode);
editText.setText(barcode);
}
public void scanBarcode(){
Barcode barcode = new Barcode();
barcode.setTargetFragment(PlaceholderFragment.this, DIALOG_FRAGMENT);
FragmentTransaction fragmentTransaction =
getActivity().getFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.container, barcode);
fragmentTransaction.addToBackStack("VIEW");
fragmentTransaction.commit();
}
}
条码类:
package com.gilbert.apptastic.barcodefragment;
import android.app.Activity;
import android.app.Fragment;
import android.content.Intent;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import me.dm7.barcodescanner.zbar.Result;
import me.dm7.barcodescanner.zbar.ZBarScannerView;
public class Barcode extends Fragment implements ZBarScannerView.ResultHandler {
private ZBarScannerView mScannerView;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
mScannerView = new ZBarScannerView(getActivity());
return mScannerView;
}
@Override
public void onResume() {
super.onResume();
mScannerView.setResultHandler(this);
mScannerView.startCamera();
}
@Override
public void handleResult(Result rawResult) {
if(!rawResult.getContents().isEmpty()){
mScannerView.startCamera();
// Toast.makeText(getActivity(),"Success",Toast.LENGTH_SHORT).show();
Intent intent = new Intent();
intent.putExtra("barcode", rawResult.getContents());
getTargetFragment().onActivityResult(getTargetRequestCode(), Activity.RESULT_OK, intent);
getFragmentManager().popBackStack();
}else {
// Toast.makeText(getActivity(),"Fail",Toast.LENGTH_SHORT).show();
getFragmentManager().popBackStack();
mScannerView.startCamera();
}
}
@Override
public void onPause() {
super.onPause();
mScannerView.stopCamera();
}
}
我的布局文件:
<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:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context=".MainActivity$PlaceholderFragment">
<Button
style="?android:attr/buttonStyleSmall"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Scan"
android:id="@+id/button"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true" />
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_above="@+id/button">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Text"
android:id="@+id/textView"
android:layout_gravity="center_horizontal" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Large Text"
android:id="@+id/textView2"
android:layout_gravity="center_horizontal" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:text="Medium Text"
android:id="@+id/textView3"
android:layout_gravity="center_horizontal" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceSmall"
android:text="Small Text"
android:id="@+id/textView4"
android:layout_gravity="center_horizontal" />
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/editText"
android:hint="Barcode"
android:layout_gravity="center_horizontal" />
</LinearLayout>
</RelativeLayout>
【问题讨论】:
-
尝试使用条形码作为字符串创建 toast 并查看字符串是否成功传递
-
@HirakChhatbar 做到了,而且效果很好
-
我已经用可能的解决方案给出了答案。请检查他们是否有帮助
-
我不相信
textView仍然是一个有效的参考。可能您需要再次搜索它。我会试试((TextView) getView().findViewById(R.id.textView)).setText(barcode); -
@njzk2 我得到“java.lang.NullPointerException”我使用它