当我想获取整数值并将其传递给电子邮件时，java应用程序崩溃

Question

我试图从editText向电子邮件传递整数值，但应用程序一直崩溃

public class EditProductActivity extends AppCompatActivity implements LoaderManager.LoaderCallbacks<Cursor> {`

 private EditText mQuantityEditText;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_edit);

    // Initializing all the view variables associated to both product activity "modes".
    mNameEditText = (EditText) findViewById(R.id.ProductNameEditText);
    mSupplierEditText = (EditText) findViewById(R.id.SupplierEditView);
    mPriceEditText = (EditText) findViewById(R.id.PriceEditText);
    mQuantityEditText = (EditText) findViewById(R.id.QuantityEditText);
    mProductImageView = (ImageView) findViewById(R.id.ProductImageView);


    // Set onTouchListeners for all editviews/imageviews
    mNameEditText.setOnTouchListener(mTouchListener);
    mQuantityEditText.setOnTouchListener(mTouchListener);
    mSupplierEditText.setOnTouchListener(mTouchListener);
    mPriceEditText.setOnTouchListener(mTouchListener);
    mProductImageView.setOnTouchListener(mTouchListener);
  // If data is passed by intent, then display the current product in questions information\
    // Also known as "Edit mode"
    if (getIntent().getData() != null) {
        int i =Integer.parseInt(mQuantityEditText.getText().toString());
        Log.i("i===", String.valueOf(i));
        // Defining all the variables required for just the editing process
        mQuantityTextView = (TextView) findViewById(R.id.displayQuantity);
        mSaleButton = (Button) findViewById(R.id.SaleButton);
        mIncrementButton = (ImageButton) findViewById(R.id.IncrementButton);
        mDecrementButton = (ImageButton) findViewById(R.id.DecrementButton);
        mOrderButton = (ImageButton) findViewById(R.id.OrderButton);
// Adding additional onTouchListeners to the newly tracked variables:
        mSaleButton.setOnTouchListener(mTouchListener);
        mIncrementButton.setOnTouchListener(mTouchListener);
        mDecrementButton.setOnTouchListener(mTouchListener);

        // Since we are in editmode, can hide the quantity editText and replace it with the
        // quantity controller view layout.
        mQuantityEditText.setVisibility(View.GONE);
        findViewById(R.id.QantityLayout).setVisibility(View.VISIBLE);

        mCurrentProductUri = getIntent().getData();
        setTitle(getString(R.string.edit_product));

        // Handle the various quantity alteration options
        mSaleButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                alterQuantity(-1);
            }
        });
        mIncrementButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                alterQuantity(1);
            }
        });
        mDecrementButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                alterQuantity(-1);
            }
        });

//下面，我试图从编辑文本中获取整数值，但当我按“订单”按钮将其发送到电子邮件时，应用程序崩溃

        // Handle the order button request
        mOrderButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

//这里我再试一次：

 public void onClick(View v) {
                int i =Integer.parseInt(mQuantityEditText.getText().toString());
                Intent emailIntent = new Intent(Intent.ACTION_SENDTO);
                emailIntent.setData(Uri.parse("mailto:" + mSupplierEditText.getText().toString()));
                emailIntent.putExtra(Intent.EXTRA_SUBJECT, "Product Order");
                emailIntent.putExtra(Intent.EXTRA_TEXT, "I would like to order "+String.valueOf(i));
                try {
                    startActivity(Intent.createChooser(emailIntent, "Send email using..."));
                } catch (安卓.content.ActivityNotFoundException ex) {
                    Toast.makeText(EditProductActivity.this, "No email clients installed.", Toast.LENGTH_SHORT).show();
                }
            }
        });

LOGCAT错误

06-16 05:02:29.790 4135-4135/com.example.mohammedragab.productinventoryapp E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.mohammedragab.productinventoryapp, PID: 4135 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.mohammedragab.productinventoryapp/com.example.mohammedragab.productinventoryapp.EditProductActivity}: java.lang.NumberFormatException: For input string: "" at 安卓.app.ActivityThread.performLaunchActivity(ActivityThread.java:2665) at 安卓.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726) at 安卓.app.ActivityThread.-wrap12(ActivityThread.java) at 安卓.app.ActivityThread$H.handleMessage(ActivityThread.java:1477) at 安卓.os.Handler.dispatchMessage(Handler.java:102) at 安卓.os.Looper.loop(Looper.java:154) at 安卓.app.ActivityThread.main(ActivityThread.java:6119) at java.lang.reflect.Method.invoke(Native Method) at com.安卓.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886) at com.安卓.internal.os.ZygoteInit.main(ZygoteInit.java:776) Caused by: java.lang.NumberFormatException: For input string: "" at java.lang.Integer.parseInt(Integer.java:533) at java.lang.Integer.parseInt(Integer.java:556) at com.example.mohammedragab.productinventoryapp.EditProductActivity.onCreate(EditProductActivity.java:104) at 安卓.app.Activity.performCreate(Activity.java:6679) at 安卓.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118) at 安卓.app.ActivityThread.performLaunchActivity(ActivityThread.java:2618) at 安卓.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)  at 安卓.app.ActivityThread.-wrap12(ActivityThread.java)  at 安卓.app.ActivityThread$H.handleMessage(ActivityThread.java:1477)  at 安卓.os.Handler.dispatchMessage(Handler.java:102)  at 安卓.os.Looper.loop(Looper.java:154)  at 安卓.app.ActivityThread.main(ActivityThread.java:6119)  at java.lang.reflect.Method.invoke(Native Method)  at com.安卓.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)  at com.安卓.internal.os.ZygoteInit.main(ZygoteInit.java:776)

Answer 1

您的应用程序正在崩溃，因为inputField是空字符串，如错误日志所示：

java.lang.NumberFormatException: For input string: ""

这是因为onCreate()——它实例化了TextInput字段，这意味着当您尝试getText()时，它将是空的。这就解释了NumberFormatException被提出的原因

int i =Integer.parseInt(mQuantityEditText.getText().toString());

要修复它：

从onCreate()中删除这一行，因为同一行已经存在于onClick()事件处理程序中

int i =Integer.parseInt(mQuantityEditText.getText().toString());

以下是单击处理程序的工作代码：

mOrderButton.setOnClickListener(new View.OnClickListener() {
     @Override
     public void onClick(View v) {
        String textFromInput = mQuantityEditText.getText().toString();
        String supplierText  = mSupplierEditText.getText().toString();
        if(!textFromInput.isEmpty() && !supplierText.isEmpty()){
            int i =Integer.parseInt(textFromInput);
            Intent emailIntent = new Intent(Intent.ACTION_SENDTO);
            emailIntent.setData(Uri.parse("mailto:" + supplierText));
            emailIntent.putExtra(Intent.EXTRA_SUBJECT, "Product Order");
            emailIntent.putExtra(Intent.EXTRA_TEXT, "I would like to order "+String.valueOf(i));
            try {
                 startActivity(Intent.createChooser(emailIntent, "Send email using..."));
            } catch (android.content.ActivityNotFoundException ex) {
                Toast.makeText(EditProductActivity.this, "No email clients installed.", Toast.LENGTH_SHORT).show();
            }
        }else{
            //The textfield is empty, do something about it...
        }
     }
});