这个函数对我有用

private void checkForm() {
    EditText[] allFields = {
        field1_txt,
        field2_txt,
        field3_txt,
        field4_txt
    };
    
    List < EditText > ErrorFields = new ArrayList < EditText > (); 

    for (EditText edit: allFields) {
        if (TextUtils.isEmpty(edit.getText())) {

            // EditText was empty
            ErrorFields.add(edit); //add empty Edittext only in this ArayList
            
            for (int i = 0; i < ErrorFields.size(); i++) {
                EditText currentField = ErrorFields.get(i);
                currentField.setError("this field required");
                currentField.requestFocus();
            }
        }
    }
}

使用TextUtils。isEmpty(“文本”);对于单行代码

我想做一些类似的事情。但是从edit text中获取文本值并像(str=="")那样进行比较对我来说并不管用。所以更好的选择是:

EditText eText = (EditText) findViewById(R.id.etext);

if (etext.getText().length() == 0)
{//do what you want }

效果很好。

试试这个吧: 它在Kotlin

//button from xml
button.setOnClickListener{                                         
    val new=addText.text.toString()//addText is an EditText
    if(new=isNotEmpty())
    {
         //do something
    }
    else{
        new.setError("Enter some msg")
        //or
        Toast.makeText(applicationContext, "Enter some message ", Toast.LENGTH_SHORT).show()
    }
}

谢谢你！

我使用这个方法，使用trim()来避免空格:

EditText myEditText = (EditText) findViewById(R.id.editUsername);
if ("".equals(myEditText.getText().toString().trim()) {
    Toast.makeText(this, "You did not enter a value!", Toast.LENGTH_LONG).show();
    return;
}

一个例子，如果你有几个EditText´

if (("".equals(edtUser.getText().toString().trim()) || "".equals(edtPassword.getText().toString().trim()))){
        Toast.makeText(this, "a value is missing!", Toast.LENGTH_LONG).show();
        return;
}

我使用TextUtils来做这个:

if (TextUtils.isEmpty(UsernameInfo.getText())) {
    validationError = true;
    validationErrorMessage.append(getResources().getString(R.string.error_blank_username));
}