Question

我有两个名为txtA的文本框，txtB

var count;//which needs to be compared with BValue
var AValue = $("#txtA").val();
var BValue = $("#txtB").val();

 if (AValue  == "") {
            alert("Enter AValue and continue");
        } else if (BValue  == "") {
            alert("Enter To BValue and continue");
        } else if (AValue  > BValue ) {
            alert("AValue should be lesser than To BValue");
        } else if (AValue == "" || BValue == "") {
            alert("Please enter the AValue and BValue to continue");
        } else if (AValue == "0") {
            alert("Invalid AValue");
        } else if (BValue  > count) {
            alert("Invalid BValue");
        } else {
             // do some operations here
        }

所有条件都顺利通过，但BValue > count虽然符合条件<{p>}但却触发了我

Answer 1

使用：

if ( AValue == ""){

}

或者

if ( ($("#txtA").val()) == "" ){

}

Answer 2

检查此工作示例。

package com.example.asad.save_photo;

import android.app.Activity;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.net.Uri;
import android.os.Environment;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

import com.google.android.gms.tasks.OnFailureListener;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.firebase.storage.FirebaseStorage;
import com.google.firebase.storage.StorageMetadata;
import com.google.firebase.storage.StorageReference;
import com.google.firebase.storage.UploadTask;

import java.io.ByteArrayOutputStream;
import java.io.File;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        FirebaseStorage storage = FirebaseStorage.getInstance();

        StorageReference storageRef = storage.getReferenceFromUrl("gs://savephoto-a1cc3.appspot.com");

        final StorageReference mountainsRef = storageRef.child("images");

        Button butt = (Button) findViewById(R.id.button);


        butt.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                ImageView imageView = (ImageView) findViewById(R.id.image);
                imageView.setImageResource(R.drawable.back2);
                imageView.setImageResource(R.drawable.back2);

                imageView.setDrawingCacheEnabled(true);
                imageView.buildDrawingCache();
                Bitmap bitmap = imageView.getDrawingCache();

                ByteArrayOutputStream baos = new ByteArrayOutputStream();
                bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);
                byte[] data = baos.toByteArray();

                UploadTask uploadTask = mountainsRef.putBytes(data);
                uploadTask.addOnFailureListener(new OnFailureListener() {
                    @Override
                    public void onFailure(@NonNull Exception exception) {
                        // Handle unsuccessful uploads
                        showToast("unsuccessful");
                    }
                }).addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
                    @Override
                    public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
                        // taskSnapshot.getMetadata() contains file metadata such as size, content-type, and download URL.
                        //Uri downloadUrl = taskSnapshot.getDownloadUrl();
                        showToast("success !!!!!");
                    }
                });


            }
        });

    }

    public void showToast(String s) {
        Toast.makeText(this,s,Toast.LENGTH_SHORT).show();
    }
}

简单如果没有其他工作

2 个答案: