android - getClipdata().GetItemCount() 空指针异常

Question

在您将问题标记为重复之前请阅读问题...

所以我正在尝试使用 Intent 从图库中选择多张图片。当我选择多于 1 张图片时，它工作正常，当我只选择 1 张图片时，它会生成此错误。我寻找了每个 NullPointer 异常问题，但没有成功。

FATAL EXCEPTION: main
              Process: com.blackhat.applocker, PID: 1892
              java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=2, result=-1, data=Intent { dat=content://com.android.providers.media.documents/document/image:10227 flg=0x1 }} to activity {com.blackhat.applocker/com.blackhat.applocker.ProtactGallery}: java.lang.NullPointerException: Attempt to invoke virtual method 'int android.content.ClipData.getItemCount()' on a null object reference
                  at android.app.ActivityThread.deliverResults(ActivityThread.java:3839)
                  at android.app.ActivityThread.handleSendResult(ActivityThread.java:3882)
                  at android.app.ActivityThread.access$1300(ActivityThread.java:178)
                  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1519)
                  at android.os.Handler.dispatchMessage(Handler.java:111)
                  at android.os.Looper.loop(Looper.java:194)
                  at android.app.ActivityThread.main(ActivityThread.java:5637)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at java.lang.reflect.Method.invoke(Method.java:372)
                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:960)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
                  at de.robv.android.xposed.XposedBridge.main(XposedBridge.java:114)
               Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int android.content.ClipData.getItemCount()' on a null object reference
                  at com.blackhat.applocker.ProtactGallery.onActivityResult(ProtactGallery.java:63)
                  at android.app.Activity.dispatchActivityResult(Activity.java:6302)
                  at android.app.ActivityThread.deliverResults(ActivityThread.java:3835)

这是我用于 Intent 的代码

Intent intent = new Intent();
            intent.setType("image/*");
            intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);
            intent.setAction(Intent.ACTION_GET_CONTENT);
            startActivityForResult(Intent.createChooser(intent,"Select Picture"), 2);

这是我的图像 ActivityResult 方法内容

if(requestCode == 2){
        if(data.getClipData().getItemCount() == 1){
            Toast.makeText(this, "Only 1", Toast.LENGTH_SHORT).show();
        }else{
            for(int i=0;i<data.getClipData().getItemCount();i++){
                path.add(data.getClipData().getItemAt(i).getUri());
                Log.d("RjList",path.get(i).toString());
                Random rn=new Random();
                if(copyFileFromUri(this,data.getClipData().getItemAt(i).getUri(),String.valueOf(rn.nextInt(500)))){
                    Toast.makeText(this, "Done", Toast.LENGTH_SHORT).show();
                }
            }
        }
    }

它适用于多张图片。

为什么当我只选择 1 张图像时它不起作用？？任何建议都会被应用....

Answer 1

我相信 ClipData 只有在有多个 Uris 要发回时才会返回。当只有一个时，您可以使用 getData 获取它。你可以做这样的事情来处理:

List<Uri> uris = new ArrayList<>();
ClipData cd = data.getClipData();

if ( cd == null ) {  
    Uri uri = data.getData();  
    uris.add(uri);  
} 
else {
    for (int i = 0; i < cd.getItemCount(); i++) {  
        ClipData.Item item = cd.getItemAt(i);  
        Uri uri = item.getUri();  
        uris.add(uri);  
    }  
}