我正在尝试构建一个简单的计算器应用程序,该应用程序具有:
3EditText
代表 2 个数字和结果。
6 Buttons
+ - * / = 清除。
在 AVD 上运行此应用程序时,它会闪烁“不幸的是应用程序已停止!”
这意味着会遇到某种异常,但我无法理解是什么。
当我检查 Logcat 时,有一些东西"EditText cannot be typecast to String"。
请帮我调试这个异常。
package com.example.calci_ver1;
import android.os.Bundle;
import android.app.Activity;
import android.view.*;
import android.widget.*;
public class MainActivity extends Activity {
Button badd, bsub, bmul, bdiv, beq, bclr;
static EditText et1, et2, et3;
static int i=0, n1, n2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
badd = (Button)findViewById(R.id.button1);
bsub = (Button)findViewById(R.id.button2);
bmul = (Button)findViewById(R.id.button3);
bdiv = (Button)findViewById(R.id.button4);
beq = (Button)findViewById(R.id.button5);
bclr = (Button)findViewById(R.id.button6);
et1 = (EditText)findViewById(R.id.editText1);
et2 = (EditText)findViewById(R.id.editText2);
et3 = (EditText)findViewById(R.id.editText3);
badd.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
i = 1;
}
});
bsub.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
i = 2;
}
});
bmul.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
i = 3;
}
});
bdiv.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
i = 4;
}
});
beq.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
String s1, s2;
s1 = et1.getText().toString();
s2 = et2.getText().toString();
n1 = Integer.parseInt(s1);
n2 = Integer.parseInt(s2);
calculation();
i = 0;
}
});
bclr.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
et1.setText("");
et2.setText("");
et3.setText("");
}
});
}
public static void calculation() {
switch(i)
{
case 1: et3.setText(n1+n2);
break;
case 2: et3.setText(n1-n2);
break;
case 3: et3.setText(n1*n2);
break;
case 4: et3.setText(n1/n2);
break;
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}