[英]Check if EditText is empty
我正在制作一个数学应用程序。 我有两个数组有两组数字。 我让应用程序从每个数组中选择一个随机数。 该应用程序在TextView
显示两个数字。 它要求用户在EditText
键入添加数字的内容。 然后当用户按下“提交”时,应用程序将告诉用户他们是对还是错。
该应用程序工作,但我有一个主要问题。 如果用户未在EditText
键入任何内容并按“提交”,则app force将关闭。 我已经查看了其他问题,询问如何检查EditText
是否为空。 我尝试了不同的方法,但它仍然无效。
public class MainActivity extends Activity {
Button submitb, startb, idkb;
EditText et;
TextView tv, rig, wron;
int arrone[] = { 24, 54, 78, 96, 48, 65, 32, 45, 95, 13, 41, 55, 33, 22,
71, 5, 22, 17, 13, 29, 63, 72, 14, 81, 7 }; // One Set of Numbers//
int arrtwo[] = { 121, 132, 147, 79, 82, 723, 324, 751, 423, 454, 448,
524, 512, 852, 845, 485, 775, 186, 99 }; // Another set of Numbers//
int random1, random2, add;
int wrong = 0;
int right = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
list();
startb.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int num = (int) (Math.random() * 25);
int mun = (int) (Math.random() * 19);
random1 = arrone[num];
random2 = arrtwo[mun];
String yu = (random1 + " + " + random2 + " =");
tv.setText(yu);
et.setHint("");
idkb.setVisibility(0);
startb.setText("Next Question");
}
});
startb.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int bread2 = 0;
if (bread2 == 0) {
Toast.makeText(getApplicationContext(),
"You didn't answer the question!",
Toast.LENGTH_LONG).show();
}
int swag = random1 + random2;
String bread = et.getText().toString();
bread2 = Integer.parseInt(bread);
if (bread2 == swag) {
startb.setText("Next Question");
tv.setText("Correct");
et.setText("");
et.setHint("Click Next Question");
right++;
rig.setText("Right:" + right);
rig.setTextColor(Color.parseColor("#14df11"));
bread2 = 0;
}
else if (bread2 == 0) {
tv.setText("Wrong, the correct answer is " + swag + ".");
startb.setText("Next Question");
et.setText("");
tv.setHint("Click Next Question");
wrong++;
wron.setText("Wrong:" + wrong);
wron.setTextColor(Color.parseColor("#ff0000"));
bread2 = 0;
}
else {
tv.setText("Wrong, the correct answer is " + swag + ".");
startb.setText("Next Question");
et.setText("");
et.setHint("Click Next Question");
wrong++;
wron.setText("Wrong:" + wrong);
wron.setTextColor(Color.parseColor("#ff0000"));
bread2 = 0;
}
}
});
idkb.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int swag = random1 + random2;
tv.setText("The Correct Answer is " + swag + ".");
et.setText("");
tv.setHint("Click Next Question");
wrong++;
wron.setText("Wrong:" + wrong);
wron.setTextColor(Color.parseColor("#ff0000"));
}
});
}
private void list() {
submitb = (Button) findViewById(R.id.b1);
startb = (Button) findViewById(R.id.b2);
et = (EditText) findViewById(R.id.et1);
tv = (TextView) findViewById(R.id.tv1);
rig = (TextView) findViewById(R.id.rtv);
wron = (TextView) findViewById(R.id.wtv);
idkb = (Button) findViewById(R.id.idk);
}
几点要考虑:
在第二个onClick()中,你有一个条件:
int bread2 = 0; if (bread2 == 0) { //rest of code }
这种情况总是会让人满意,这就是你想要的吗?
您可以使用以下内容检查是否没有输入任何内容:
String bread = et.getText().toString(); // check if there is any text entered by user if (bread.length() > 0) { bread2 = Integer.parseInt(bread); if (bread2 == swag) { startb.setText("Next Question"); //the rest of the code }
不确定我是否正确理解你,但它应该很容易:
et = (EditText) findViewById(R.id.et1);
String bread = et.getText().toString();
if (bread.length() == 0){
// raise error dialogue
} else {
// continue to check the parsed integer
}
这应该都在您的点击监听器中完成。
你需要在et
之前使用findViewById
才能获得它的值。
顺便说一句,你将bread2
值设置为0,并在下一行验证它是否为0,我想这只是一个测试,不是吗?
@Override
public void onClick(View v) {
int bread2 = 0;
if (bread2 == 0) {
Toast.makeText(getApplicationContext(),
"You didn't answer the question!",
Toast.LENGTH_LONG).show();
}
int swag = random1 + random2;
et = findViewById(R.id.yourEditText);
String bread = et.getText().toString();
bread2 = Integer.parseInt(bread);
//...
希望能帮助到你!
我认为检查文本长度是一种很好的做法,例如这个功能可以帮助你...
public boolean isEditTextEmpty(EditText input){
if(input.getText().length() == 0)
return true;
else
return false;
}
if (et.getText().length == 0 || et.gettext == null ){
// do nothing
} else {
// do whatever here
}
这应该没问题
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