您好我正在使用Android启动器来显示计算器活动。它显示布局很好，但当你点击任何我需要帮助的按钮时我什么也没做什么我已经尝试了所有的东西，我感到很沮丧！任何帮助都会很棒！
Calculator.java：
package com.dva.schooltoolshome;
import java.text.DecimalFormat;
import android.annotation.SuppressLint;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.Menu;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
public class Calculator extends FragmentActivity implements OnClickListener {
private TextView calculatorDisplay;
private static final String DIGITS = "0123456789.";
private Boolean userIsInTheMiddleOfTypingANumber = false;
DecimalFormat df = new DecimalFormat("@###########");
CalculatorBrain brain;
@SuppressLint("NewApi")
@Override
protected void onCreate(Bundle savedInstanceState) {
// hide the window title.
requestWindowFeature(Window.FEATURE_NO_TITLE);
// hide the status bar and other OS-level chrome
getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_calculator);
brain = new CalculatorBrain();
calculatorDisplay = (TextView) findViewById(R.id.textView1);
df.setMinimumFractionDigits(0);
df.setMinimumIntegerDigits(1);
df.setMaximumIntegerDigits(8);
findViewById(R.id.button0).setOnClickListener(this);
findViewById(R.id.button1).setOnClickListener(this);
findViewById(R.id.button2).setOnClickListener(this);
findViewById(R.id.button3).setOnClickListener(this);
findViewById(R.id.button4).setOnClickListener(this);
findViewById(R.id.button5).setOnClickListener(this);
findViewById(R.id.button6).setOnClickListener(this);
findViewById(R.id.button7).setOnClickListener(this);
findViewById(R.id.button8).setOnClickListener(this);
findViewById(R.id.button9).setOnClickListener(this);
findViewById(R.id.buttonAdd).setOnClickListener(this);
findViewById(R.id.buttonSubtract).setOnClickListener(this);
findViewById(R.id.buttonMultiply).setOnClickListener(this);
findViewById(R.id.buttonDivide).setOnClickListener(this);
findViewById(R.id.buttonToggleSign).setOnClickListener(this);
findViewById(R.id.buttonDecimalPoint).setOnClickListener(this);
findViewById(R.id.buttonEquals).setOnClickListener(this);
findViewById(R.id.buttonClear).setOnClickListener(this);
findViewById(R.id.buttonClearMemory).setOnClickListener(this);
findViewById(R.id.buttonAddToMemory).setOnClickListener(this);
findViewById(R.id.buttonSubtractFromMemory).setOnClickListener(this);
findViewById(R.id.buttonRecallMemory).setOnClickListener(this);
// The following buttons only exist in layout-land (Landscape mode) and require extra attention.
// The messier option is to place the buttons in the regular layout too and set android:visibility="invisible".
if (findViewById(R.id.buttonSquareRoot) != null) {
findViewById(R.id.buttonSquareRoot).setOnClickListener(this);
}
if (findViewById(R.id.buttonInvert) != null) {
findViewById(R.id.buttonInvert).setOnClickListener(this);
}
if (findViewById(R.id.buttonCos) != null) {
findViewById(R.id.buttonCos).setOnClickListener(this);
}
if (findViewById(R.id.buttonSin) != null) {
findViewById(R.id.buttonSin).setOnClickListener(this);
}
// Another way to hide the window title and actionbar, but only in newer sdk's
// if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
// ActionBar actionBar = getActionBar();
// actionBar.setDisplayShowHomeEnabled(false);
// actionBar.setDisplayShowTitleEnabled(false);
// actionBar.hide();
// }
}
// @Override
public void onClick(View view) {
String buttonPressed = ((Button) view).getText().toString();
// String digits = "0123456789.";
if (DIGITS.contains(buttonPressed)) {
// digit was pressed
if (userIsInTheMiddleOfTypingANumber) {
calculatorDisplay.append(buttonPressed);
} else {
calculatorDisplay.setText(buttonPressed);
userIsInTheMiddleOfTypingANumber = true;
}
} else {
// operation was pressed
if (userIsInTheMiddleOfTypingANumber) {
brain.setOperand(Double.parseDouble(calculatorDisplay.getText().toString()));
userIsInTheMiddleOfTypingANumber = false;
}
brain.performOperation(buttonPressed);
calculatorDisplay.setText(df.format(brain.getResult()));
}
}
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
// Save variables on screen orientation change
outState.putDouble("OPERAND", brain.getResult());
outState.putDouble("MEMORY", brain.getMemory());
}
@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
// Restore variables on screen orientation change
brain.setOperand(savedInstanceState.getDouble("OPERAND"));
brain.setMemory(savedInstanceState.getDouble("MEMORY"));
calculatorDisplay.setText(df.format(brain.getResult()));
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.home, menu);
return true;
}
}
CalculatorBrain.java：
package com.dva.schooltoolshome;
public class CalculatorBrain {
// 3 + 6 = 9
// 3 & 6 are called the operand.
// The + is called the operator.
// 9 is the result of the operation.
private double operand = 0;
private double waitingOperand = 0;
private String waitingOperator = "";
private double calculatorMemory = 0;
public void setOperand(double operand) {
this.operand = operand;
}
public double getResult() {
return operand;
}
// used on screen orientation change
public void setMemory(double calculatorMemory) {
this.calculatorMemory = calculatorMemory;
}
// used on screen orientation change
public double getMemory() {
return calculatorMemory;
}
public String toString() {
return Double.toString(operand);
}
protected double performOperation(String operator) {
/*
* If you are using Java 7, then you can use switch in place of if statements
*
* switch (operator) {
* case "MC":
* calculatorMemory = 0;
* break;
* case "M+":
* calculatorMemory = calculatorMemory + operand;
* break;
* }
*/
if (operator.equals("MC")) {
calculatorMemory = 0;
} else if (operator.equals("M+")) {
calculatorMemory = calculatorMemory + operand;
} else if (operator.equals("M-")) {
calculatorMemory = calculatorMemory - operand;
} else if (operator.equals("MR")) {
operand = calculatorMemory;
} else if (operator.equals("C")) {
operand = 0;
waitingOperator = "";
waitingOperand = 0;
calculatorMemory = 0;
} else if (operator.equals("Sqrt")) {
operand = Math.sqrt(operand);
} else if (operator.equals("1/x")) {
if (operand != 0) {
operand = 1 / operand;
}
} else if (operator.equals("+/-")) {
operand = -operand;
} else if (operator.equals("sin")) {
operand = Math.sin(operand);
} else if (operator.equals("cos")) {
operand = Math.cos(operand);
} else {
performWaitingOperation();
waitingOperator = operator;
waitingOperand = operand;
}
return operand;
}
protected void performWaitingOperation() {
if (waitingOperator.equals("+")) {
operand = waitingOperand + operand;
} else if (waitingOperator.equals("*")) {
operand = waitingOperand * operand;
} else if (waitingOperator.equals("-")) {
operand = waitingOperand - operand;
} else if (waitingOperator.equals("/")) {
if (operand != 0) {
operand = waitingOperand / operand;
}
}
}
}
activity_calculator.xml：
<RelativeLayout xmlns:tools="http://schemas.android.com/tools"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/bg" >
<LinearLayout
android:id="@+id/linearLayout1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true" >
<TextView
android:id="@+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="right"
android:maxLines="1"
android:paddingLeft="10dp"
android:paddingRight="10dp"
android:text="0"
android:textAppearance="?android:attr/textAppearanceLarge"
android:textSize="40sp" />
</LinearLayout>
<LinearLayout
android:id="@+id/linearLayout2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/linearLayout1" >
<Button
android:id="@+id/buttonAddToMemory"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="M+" />
<Button
android:id="@+id/buttonSubtractFromMemory"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="M-" />
<Button
android:id="@+id/buttonRecallMemory"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="MR" />
</LinearLayout>
<LinearLayout
android:id="@+id/linearLayout3"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/linearLayout2" >
<Button
android:id="@+id/buttonClear"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="C" />
<Button
android:id="@+id/buttonToggleSign"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="+/-" />
<Button
android:id="@+id/buttonDivide"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="/" />
<Button
android:id="@+id/buttonMultiply"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="*" />
</LinearLayout>
<LinearLayout
android:id="@+id/linearLayout4"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/linearLayout3" >
<Button
android:id="@+id/button7"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="@string/button7" />
<Button
android:id="@+id/button8"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="@string/button8" />
<Button
android:id="@+id/button9"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="@string/button9" />
<Button
android:id="@+id/buttonSubtract"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="-" />
</LinearLayout>
<LinearLayout
android:id="@+id/linearLayout5"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/linearLayout4" >
<Button
android:id="@+id/button4"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="@string/button4" />
<Button
android:id="@+id/button5"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="@string/button5" />
<Button
android:id="@+id/button6"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="@string/button6" />
<Button
android:id="@+id/buttonAdd"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="+" />
</LinearLayout>
<LinearLayout
android:id="@+id/linearLayout6"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/linearLayout5"
android:baselineAligned="false" >
<LinearLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight=".75"
android:orientation="vertical" >
<LinearLayout
android:id="@+id/linearLayout7"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<Button
android:id="@+id/button1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".33"
android:text="@string/button1" />
<Button
android:id="@+id/button2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".33"
android:text="@string/button2" />
<Button
android:id="@+id/button3"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".34"
android:text="@string/button3" />
</LinearLayout>
<LinearLayout
android:id="@+id/linearLayout8"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<Button
android:id="@+id/button0"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".66"
android:text="@string/button0" />
<Button
android:id="@+id/buttonDecimalPoint"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".34"
android:text="." />
</LinearLayout>
</LinearLayout>
<Button
android:id="@+id/buttonEquals"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight=".25"
android:text="=" />
</LinearLayout>
<ImageButton
android:id="@+id/apps"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/wbrowser"
android:background="@drawable/appdrawer"
android:src="@drawable/appdrawer" />
<ImageButton
android:id="@+id/wbrowser"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:src="@drawable/browser" />
<ImageButton
android:id="@+id/ImageButton01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignTop="@+id/wbrowser"
android:background="@drawable/appdrawer"
android:src="@drawable/appdrawer" />
<Button
android:id="@+id/tools"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/ImageButton01"
android:layout_centerHorizontal="true"
android:text="Tools" />
<Button
android:id="@+id/buttonClearMemory"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_above="@+id/ImageButton01"
android:layout_alignLeft="@+id/tools"
android:layout_marginBottom="163dp"
android:layout_weight=".25"
android:text="MC" />
</RelativeLayout>
我还是Android开发的新手，所以请不要判断
问候
Rapsong11
答案 0 :(得分：0)
首先在每个按钮的OnClick（View v）函数中使用switch语句。 像这样。
public void onClick(View v)
{
case R.Id.button1
// the functionality code goes here
break;
case R.id.button2
break;
}