如图, 我的代码很简单就是两个数相加,然后再textview中显示,但是在textview01.setText(editText01+editText02);中会有这样的错误。。The operator + is undefined for the argument type(s) android.widget.EditText, android.widget.EditText
请问这是怎么回事?
请问这是怎么回事?
解决方案 »
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那两个是EditText的对象
你应该写editText01.getText()+editText02.getText()
import android.R.string;
import android.app.Activity;
import android.os.Bundle;
import android.text.Editable;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;public class Andzuoye2Activity extends Activity {
int shu1;
int shu2;
TextView textview01;
EditText editText01;
EditText editText02;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button bn=(Button)findViewById(R.id.button01); editText01=(EditText)findViewById(R.id.edittext01);
editText02=(EditText)findViewById(R.id.edittext02);
textview01=(TextView)findViewById(R.id.textview1);
shu1=Integer.parseInt(editText01.getText().toString());
shu2=Integer.parseInt(editText01.getText().toString());
bn.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
//textview01.setText(shu1+shu2);
textview01.setText(String.valueOf(shu1+shu2));
}
});
}
}这样还不行。。
package com.lyx;
import android.R.integer;
import android.R.string;
import android.app.Activity;
import android.os.Bundle;
import android.text.Editable;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class Andzuoye2Activity extends Activity {
int shu1;
int shu2;
TextView textview01;
EditText editText01;
EditText editText02;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button bn=(Button)findViewById(R.id.button01);
editText01=(EditText)findViewById(R.id.edittext01);
editText02=(EditText)findViewById(R.id.edittext02);
textview01=(TextView)findViewById(R.id.textview1);
shu1=Integer.parseInt(editText01.getText().toString());
shu2=Integer.parseInt(editText01.getText().toString()); bn.setOnClickListener(new OnClickListener()
{ public void onClick(View v)
{
//textview01.setText(shu1+shu2); textview01.setText(String.valueOf(shu1+shu2));
}
});
}
}
有错误
import android.R.integer;
import android.R.string;
import android.app.Activity;
import android.os.Bundle;
import android.text.Editable;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class Andzuoye2Activity extends Activity {
int shu1;
int shu2;
TextView textview01;
EditText editText01;
EditText editText02;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button bn=(Button)findViewById(R.id.button01);
editText01=(EditText)findViewById(R.id.edittext01);
editText02=(EditText)findViewById(R.id.edittext02);
textview01=(TextView)findViewById(R.id.textview1);
shu1=Integer.parseInt(editText01.getText().toString());
shu2=Integer.parseInt(editText01.getText().toString()); bn.setOnClickListener(new OnClickListener()
{ public void onClick(View v)
{
//textview01.setText(shu1+shu2); textview01.setText(String.valueOf(shu1+shu2));
}
});
}
}有错误
int shu2;初始值都设为0
把出错信息贴出来。logcat那一行出错信息
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" > <EditText
android:id="@+id/edittext01"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<TextView
android:id="@+id/textview1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="乘以"
/>
<EditText
android:id="@+id/edittext02"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<Button
android:id="@+id/button01"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="计算"
/></LinearLayout>
setContentView(R.layout.main);
Button bn = (Button) findViewById(R.id.button01); editText01 = (EditText) findViewById(R.id.edittext01);
editText02 = (EditText) findViewById(R.id.edittext02);
textview01 = (TextView) findViewById(R.id.textview1); bn.setOnClickListener(new OnClickListener() { public void onClick(View v) { // textview01.setText(shu1+shu2); textview01.setText(editText01.getText().toString().trim()
+ editText02.getText().toString().trim());
}
});
.toString().trim())
* Integer.valueOf(editText02.getText().toString()
.trim()));
.trim());
int num2 = Integer.valueOf(editText02.getText().toString()
.trim()); textview01.setText(String.valueOf(num1 * num2));
android:text="0"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
shu1=Integer.parseInt(editText01.getText().toString());
shu2=Integer.parseInt(editText01.getText().toString());
写到点击事件里去
package com.lyx;import android.R.integer;
import android.R.string;
import android.app.Activity;
import android.os.Bundle;
import android.text.Editable;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;public class Andzuoye2Activity extends Activity {
int shu1;
int shu2;
TextView textview01;
EditText editText01;
EditText editText02;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button bn=(Button)findViewById(R.id.button01); editText01=(EditText)findViewById(R.id.edittext01);
editText02=(EditText)findViewById(R.id.edittext02);
textview01=(TextView)findViewById(R.id.textview1);
//shu1=Integer.parseInt(editText01.getText().toString().trim());
//shu2=Integer.parseInt(editText01.getText().toString().trim());
//shu1=Integer.valueOf(editText01.getText().toString().trim());
//shu2=Integer.valueOf(editText01.getText().toString().trim());
bn.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
//textview01.setText(shu1+shu2);
//textview01.setText(String.valueOf(shu1+shu2));
//textview01.setText(shu1+shu2);
textview01.setText(Integer.valueOf(editText01.getText().toString().trim())*Integer.valueOf(editText02.getText().toString().trim()));
}
});
}
}
shu2=Integer.parseInt(editText01.getText().toString());写到事件里
2、 shu1=Integer.parseInt(editText01.getText().toString());
shu2=Integer.parseInt(editText01.getText().toString());改为shu2=Integer.parseInt(editText02.getText().toString());
3、shu1+shu2改为shu1*shu2
我现在的代码。。还是出错,有些已经注释 了
package com.lyx;import android.R.integer;
import android.R.string;
import android.app.Activity;
import android.os.Bundle;
import android.text.Editable;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;public class Andzuoye2Activity extends Activity {
int shu1;
int shu2;
TextView textview01;
EditText editText01;
EditText editText02;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button bn=(Button)findViewById(R.id.button01); editText01=(EditText)findViewById(R.id.edittext01);
editText02=(EditText)findViewById(R.id.edittext02);
textview01=(TextView)findViewById(R.id.textview1);
//shu1=Integer.parseInt(editText01.getText().toString().trim());
//shu2=Integer.parseInt(editText01.getText().toString().trim());
//shu1=Integer.valueOf(editText01.getText().toString().trim());
//shu2=Integer.valueOf(editText01.getText().toString().trim());
bn.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
//textview01.setText(shu1+shu2);
//textview01.setText(String.valueOf(shu1+shu2));
//textview01.setText(shu1+shu2);
textview01.setText(Integer.valueOf(editText01.getText().toString().trim())*Integer.valueOf(editText02.getText().toString().trim()));
}
});
}
}
textview01.setText(String.valueOf(Integer.parseInt(editText01.getText())+Integer.parseInt(editText02.getText())));少转换一次
有Integer.parseInt()方法转换成整型,然后为什么要用String.valueOf???又转换成字符串??是不是textview只能接受字符串?? 还有trim()方法是什么意思??
,
int a = Integer.parseInt(editText01.getText());
int b = Integer.parseInt(editText02.getText());
textview01.setText(a+b);
把这三句写在onClick方法内
当时我是这样想的,我把它放在外面,能传进onClick方法内。为什么不能传进来?