我刚刚开始安装android编程，我想制作一个sorta计算器。
package com.example.gourab.test;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
public void putDigits(View view)
{
TextView display = (TextView) findViewById(R.id.display);
String prev = ((TextView) findViewById(R.id.display)).getText().toString();
int prevint = Integer.parseInt(prev);
switch (view.getId())
{
case R.id.num1:
display.setText(prevint * 10 + 1);
break;
case R.id.num2:
display.setText(prevint * 10 + 2);
break;
}
}
}
我刚刚在交换机中使用了两个用于测试的案例！
这是我的activity_main.xml：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:id="@+id/display"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:maxLines="1"
android:height="30dp"
android:text="0"/>
<Button
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="1"
android:id="@+id/num1"
android:layout_marginTop="150dp"
android:layout_below="@+id/display"
android:layout_toLeftOf="@+id/num2"
android:layout_toStartOf="@+id/num2"
android:layout_marginRight="37dp"
android:layout_marginEnd="37dp"
android:onClick="putDigits" />
<Button
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="2"
android:id="@+id/num2"
android:layout_alignTop="@+id/num1"
android:layout_toLeftOf="@+id/num3"
android:layout_toStartOf="@+id/num3"
android:layout_marginRight="38dp"
android:layout_marginEnd="38dp"
android:textColor="#f00"
android:onClick="putDigits" />
<Button
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="3"
android:id="@+id/num3"
android:layout_alignTop="@+id/num2"
android:layout_alignRight="@+id/display"
android:layout_alignEnd="@+id/display"
android:onClick="putDigits" />
<Button
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="4"
android:id="@+id/num4"
android:layout_marginTop="27dp"
android:layout_below="@+id/num1"
android:layout_alignLeft="@+id/num1"
android:layout_alignStart="@+id/num1"
android:onClick="putDigits" />
<Button
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="5"
android:id="@+id/num5"
android:layout_alignBottom="@+id/num4"
android:layout_toRightOf="@+id/num1"
android:layout_toEndOf="@+id/num1"
android:onClick="putDigits" />
<Button
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="6"
android:id="@+id/num6"
android:layout_alignTop="@+id/num5"
android:layout_alignLeft="@+id/num3"
android:layout_alignStart="@+id/num3"
android:onClick="putDigits" />
<Button
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="7"
android:id="@+id/num7"
android:layout_marginTop="29dp"
android:layout_below="@+id/num4"
android:layout_alignLeft="@+id/num4"
android:layout_alignStart="@+id/num4"
android:onClick="putDigits" />
<Button
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="8"
android:id="@+id/num8"
android:layout_alignTop="@+id/num7"
android:layout_alignLeft="@+id/num5"
android:layout_alignStart="@+id/num5"
android:onClick="putDigits" />
<Button
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="9"
android:id="@+id/num9"
android:layout_alignTop="@+id/num8"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:onClick="putDigits" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="×"
android:id="@+id/multiply"
android:layout_alignTop="@+id/num1"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="÷"
android:id="@+id/divide"
android:layout_alignTop="@+id/num4"
android:layout_alignRight="@+id/multiply"
android:layout_alignEnd="@+id/multiply" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="+"
android:id="@+id/add"
android:layout_alignBottom="@+id/num7"
android:layout_alignRight="@+id/divide"
android:layout_alignEnd="@+id/divide" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="="
android:id="@+id/equal"
android:layout_below="@+id/num8"
android:layout_alignRight="@+id/num9"
android:layout_alignEnd="@+id/num9" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="-"
android:id="@+id/subtract"
android:layout_below="@+id/num7"
android:layout_alignLeft="@+id/add"
android:layout_alignStart="@+id/add" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="0"
android:id="@+id/num0"
android:layout_alignBottom="@+id/equal"
android:layout_alignLeft="@+id/num7"
android:layout_alignStart="@+id/num7" />
</RelativeLayout>
它给了我这个错误 -
09-17 00:14:22.932 1643-1643/com.example.gourab.test E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.gourab.test, PID: 1643
java.lang.IllegalStateException: Could not execute method of the activity
at android.view.View$1.onClick(View.java:4025)
at android.view.View.performClick(View.java:4785)
at android.view.View$PerformClick.run(View.java:19884)
at android.os.Handler.handleCallback(Handler.java:746)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5343)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:905)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:700)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at android.view.View$1.onClick(View.java:4020)
at android.view.View.performClick(View.java:4785)
at android.view.View$PerformClick.run(View.java:19884)
at android.os.Handler.handleCallback(Handler.java:746)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5343)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:905)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:700)
Caused by: android.content.res.Resources$NotFoundException: String resource ID #0x1
at android.content.res.Resources.getText(Resources.java:299)
at android.widget.TextView.setText(TextView.java:4138)
at com.example.gourab.test.MainActivity.putDigits(MainActivity.java:48)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at android.view.View$1.onClick(View.java:4020)
at android.view.View.performClick(View.java:4785)
at android.view.View$PerformClick.run(View.java:19884)
at android.os.Handler.handleCallback(Handler.java:746)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5343)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:905)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:700)
我不知道是什么原因引起的。但任何帮助都会非常感激。
谢谢！