Question

如果用户点击一个按钮，我想在每个“空”文本框中设置一个“0”，以避免应用程序中的错误，任何帮助？我不知道该怎么做

package com.doko.most;
 import android.app.Activity;
 import android.os.Bundle;
 import android.widget.EditText;
 import android.widget.TextView;
 import android.widget.Button;
 import android.view.View;
public class doko extends Activity {
private EditText bx1;
private EditText bx2;
private TextView txt3;
private Button btncalcular;
private Button btnreset;
private double variable1 = 0;
private double variable2 = 0;
private double variable3 = 0;
    /** Called when the activity is first created. */

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    initControls();
}
private void initControls()
{
bx1 = (EditText)findViewById(R.id.bx1);
bx2 = (EditText)findViewById(R.id.bx2);
txt3 = (TextView)findViewById(R.id.txt3);
btncalcular = (Button)findViewById(R.id.btncalcular);
btnreset = (Button)findViewById(R.id.btnreset);
btncalcular.setOnClickListener(new Button.OnClickListener() { public void onClick (View v){ calcular(); }});
btnreset.setOnClickListener(new Button.OnClickListener() { public void onClick (View v){ reset(); }});
 }

    private void calcular()
 {
variable1 = Double.parseDouble(bx1.getText().toString());
variable2 = Double.parseDouble(bx2.getText().toString());
variable3 = Math.sqrt(1*2/3600);
txt3.setText(Double.toString(variable3));
    }
  private void reset(){
bx1.setText("");

bx2.setText("");

}
   }

Answer 1

在EditText中设置Hint属性防爆。

并在getText（）

时检查它

使用str.isEmpty（）和str.length来检查用户的inpupt

另一种方式：将EditText的inputType设置为数字并设置输入过滤器离。

InputFilter [] FilterArray = new InputFilter [1];

FilterArray [0] = new InputFilter.LengthFilter（4）;

input.setFilters（FilterArray）;

Answer 2

尝试类似这样的事情，快速而肮脏：

private void calcular() {
    try {
        variable1 = Double.parseDouble(bx1.getText().toString());
    }
    catch(NumberFormatException e) {
        bx1.setText("0");
    }
    try {
        variable2 = Double.parseDouble(bx2.getText().toString());
    }
    catch(NumberFormatException e) {
        bx2.setText("0");
    }
    variable3 = Math.sqrt(1*2/3600);
    txt3.setText(Double.toString(3));
}

Android - 如果TextBox为空，如何在单击“按钮”时添加“0”“”

2 个答案: