检查编辑文本中的空值

Question

当我要检查我创建的edittext中的空值时出现错误。 变成我的源代码错误

btnSave.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String code = etCode.getText().toString();
                String name = etName.getText().toString();
                float price = Float.parseFloat(etPrice.getText().toString());
                int qty = Integer.parseInt(etQty.getText().toString());
                if(code.length() != 0 && name.length() != 0 && price.length() != 0 && qty.length() != 0){
                 myDB.addData(code, name, price, qty);
                    etCode.setText("");
                    etName.setText("");
                    etPrice.setText("");
                    etQty.setText("");
                }else{
                    Toast.makeText(MainActivity.this,"You must put something in the text field!",Toast.LENGTH_LONG).show();
                }
                }

        });

如何解决我的问题？

Answer 1

尝试使用

TextUtils.isEmpty(editText.getText().toString());

通常，您永远不会在文本字段中出现null，但请在上面的行中检查它是否为空。 因此“”和null都将为您返回true

Answer 2

我相信您的错误java.lang.NumberFormatException: Invalid float: ""

那是因为您试图将空值转换为float 。

您可以按照以下步骤进行。

btnSave.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String code = etCode.getText().toString();
            String name = etName.getText().toString();
            String price = etPrice.getText().toString();
            String qty = etQty.getText().toString();
            if(code.isEmpty() && name.isEmpty() && price.isEmpty() && qty.isEmpty(){
                float price1 = Float.parseFloat(etPrice.getText().toString());
                int qty1 = Integer.parseInt(etQty.getText().toString());
                myDB.addData(code, name, price1, qty1);
                etCode.setText("");
                etName.setText("");
                etPrice.setText("");
                etQty.setText("");
            }else{
                Toast.makeText(MainActivity.this,"You must put something in the text field!",Toast.LENGTH_LONG).show();
            }
        }

    });

Answer 3

使用

if (TextUtils.isEmpty(edittext.getText().toString()) {
    Log.d("ERROR","Edittext is empty");
}

Answer 4

你可以这样检查

if(etCode.getText().toString().trim().equalsIgnoreCase(""))
{
// etCode edittext is empty
}

Answer 5

尝试这个

    /*
     *  for checking String valid or not
     */
    public boolean validateString(String data) {
        return (data != null && !data.isEmpty() && data.length() > 0 && !data.equals("null"));
    }

if(validateString(edittext.getText().toString()){
//Valid String
}

Answer 6

尝试这个：

 btnSave.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { String code = etCode.getText().toString(); String name = etName.getText().toString(); float price = Float.parseFloat(etPrice.getText().toString()); int qty = Integer.parseInt(etQty.getText().toString()); if(code.length() != 0 && name.length() != 0 && price != 0 && qty != 0){ myDB.addData(code, name, price, qty); etCode.setText(""); etName.setText(""); etPrice.setText(""); etQty.setText(""); }else{ Toast.makeText(MainActivity.this,"You must put something in the text field!",Toast.LENGTH_LONG).show(); } } }); 

Answer 7

您可以这样尝试：

btnSave.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
            String code = etCode.getText().toString();
            String name = etName.getText().toString();
            String priceStr = etPrice.getText().toString();
            String qtyStr = etQty.getText().toString();
            float price;
            int qty;
            if(code.length()==0) {
                Toast.makeText(MainActivity.this,"Your code is empty!",Toast.LENGTH_LONG).show();
            }
            if(name.length()==0) {
                Toast.makeText(MainActivity.this,"Your name is empty!",Toast.LENGTH_LONG).show();
            }
            if(priceStr.length()==0) {
                Toast.makeText(MainActivity.this,"Your price is empty!",Toast.LENGTH_LONG).show();
            }else {
                try {
                    price = Float.parseFloat(priceStr);
                }catch (Exception e) {
                    Toast.makeText(MainActivity.this,"Your price is not valid!",Toast.LENGTH_LONG).show();
                }
            }
            if(qtyStr.length()==0) {
                Toast.makeText(MainActivity.this,"Your qty is empty!",Toast.LENGTH_LONG).show();
            }else {
                try {
                    qty = Integer.parseInt(qtyStr);
                }catch (Exception e) {
                    Toast.makeText(MainActivity.this,"Your qty is not valid!",Toast.LENGTH_LONG).show();
                }
            }
                myDB.addData(code, name, price, qty);
                etCode.setText("");
                etName.setText("");
                etPrice.setText("");
                etQty.setText("");
            }

        });