http://www.itechcode.com/2012/03/18/create-calculator-in-android-programming/
我使用他的源代码，但它似乎与我用过的“初级水平”编程非常不同，即创建新项目，修改布局，在main.java中引用等。
我正在尝试使用他的源代码并修改/创建新操作，并可能添加一项活动。如果没有不同的布局，我通常会知道如何做大部分的事情。谢谢！
package com.pragmatouch.calculator;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.util.Iterator;
import java.util.Stack;
import android.app.Activity;
import android.os.Bundle;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.TextView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.GridView;
import android.view.View;
import android.view.View.OnClickListener;
public class main extends Activity {
GridView mKeypadGrid;
TextView userInputText;
TextView memoryStatText;
Stack<String> mInputStack;
Stack<String> mOperationStack;
KeypadAdapter mKeypadAdapter;
TextView mStackText;
boolean resetInput = false;
boolean hasFinalResult = false;
String mDecimalSeperator;
double memoryValue = Double.NaN;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
DecimalFormat currencyFormatter = (DecimalFormat) NumberFormat
.getInstance();
char decimalSeperator = currencyFormatter.getDecimalFormatSymbols()
.getDecimalSeparator();
mDecimalSeperator = Character.toString(decimalSeperator);
setContentView(R.layout.main);
// Create the stack
mInputStack = new Stack<String>();
mOperationStack = new Stack<String>();
// Get reference to the keypad button GridView
mKeypadGrid = (GridView) findViewById(R.id.grdButtons);
// Get reference to the user input TextView
userInputText = (TextView) findViewById(R.id.txtInput);
userInputText.setText("0");
memoryStatText = (TextView) findViewById(R.id.txtMemory);
memoryStatText.setText("");
mStackText = (TextView) findViewById(R.id.txtStack);
// Create Keypad Adapter
mKeypadAdapter = new KeypadAdapter(this);
// Set adapter of the keypad grid
mKeypadGrid.setAdapter(mKeypadAdapter);
// Set button click listener of the keypad adapter
mKeypadAdapter.setOnButtonClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Button btn = (Button) v;
// Get the KeypadButton value which is used to identify the
// keypad button from the Button's tag
KeypadButton keypadButton = (KeypadButton) btn.getTag();
// Process keypad button
ProcessKeypadInput(keypadButton);
}
});
mKeypadGrid.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v,
int position, long id) {
}
});
}
private void ProcessKeypadInput(KeypadButton keypadButton) {
//Toast.makeText(this, keypadButton.getText(), Toast.LENGTH_SHORT).show();
String text = keypadButton.getText().toString();
String currentInput = userInputText.getText().toString();
int currentInputLen = currentInput.length();
String evalResult = null;
double userInputValue = Double.NaN;
switch (keypadButton) {
case BACKSPACE: // Handle backspace
// If has operand skip backspace
if (resetInput)
return;
int endIndex = currentInputLen - 1;
// There is one character at input so reset input to 0
if (endIndex < 1) {
userInputText.setText("0");
}
// Trim last character of the input text
else {
userInputText.setText(currentInput.subSequence(0, endIndex));
}
break;
case SIGN: // Handle -/+ sign
// input has text and is different than initial value 0
if (currentInputLen > 0 && currentInput != "0") {
// Already has (-) sign. Remove that sign
if (currentInput.charAt(0) == '-') {
userInputText.setText(currentInput.subSequence(1,
currentInputLen));
}
// Prepend (-) sign
else {
userInputText.setText("-" + currentInput.toString());
}
}
break;
case CE: // Handle clear input
userInputText.setText("0");
break;
case C: // Handle clear input and stack
userInputText.setText("0");
clearStacks();
break;
case DECIMAL_SEP: // Handle decimal seperator
if (hasFinalResult || resetInput) {
userInputText.setText("0" + mDecimalSeperator);
hasFinalResult = false;
resetInput = false;
} else if (currentInput.contains("."))
return;
else
userInputText.append(mDecimalSeperator);
break;
case DIV:
case PLUS:
case MINUS:
case MULTIPLY:
if (resetInput) {
mInputStack.pop();
mOperationStack.pop();
} else {
if (currentInput.charAt(0) == '-') {
mInputStack.add("(" + currentInput + ")");
} else {
mInputStack.add(currentInput);
}
mOperationStack.add(currentInput);
}
mInputStack.add(text);
mOperationStack.add(text);
dumpInputStack();
evalResult = evaluateResult(false);
if (evalResult != null)
userInputText.setText(evalResult);
resetInput = true;
break;
case CALCULATE:
if (mOperationStack.size() == 0)
break;
mOperationStack.add(currentInput);
evalResult = evaluateResult(true);
if (evalResult != null) {
clearStacks();
userInputText.setText(evalResult);
resetInput = false;
hasFinalResult = true;
}
break;
case M_ADD: // Add user input value to memory buffer
userInputValue = tryParseUserInput();
if (Double.isNaN(userInputValue))
return;
if (Double.isNaN(memoryValue))
memoryValue = 0;
memoryValue += userInputValue;
displayMemoryStat();
hasFinalResult = true;
break;
case M_REMOVE: // Subtract user input value to memory buffer
userInputValue = tryParseUserInput();
if (Double.isNaN(userInputValue))
return;
if (Double.isNaN(memoryValue))
memoryValue = 0;
memoryValue -= userInputValue;
displayMemoryStat();
hasFinalResult = true;
break;
case MC: // Reset memory buffer to 0
memoryValue = Double.NaN;
displayMemoryStat();
break;
case MR: // Read memoryBuffer value
if (Double.isNaN(memoryValue))
return;
userInputText.setText(doubleToString(memoryValue));
displayMemoryStat();
break;
case MS: // Set memoryBuffer value to user input
userInputValue = tryParseUserInput();
if (Double.isNaN(userInputValue))
return;
memoryValue = userInputValue;
displayMemoryStat();
hasFinalResult = true;
break;
case PRGM:
break;
default:
if (Character.isDigit(text.charAt(0))) {
if (currentInput.equals("0") || resetInput || hasFinalResult) {
userInputText.setText(text);
resetInput = false;
hasFinalResult = false;
} else {
userInputText.append(text);
resetInput = false;
}
}
break;
}
}
private void clearStacks() {
mInputStack.clear();
mOperationStack.clear();
mStackText.setText("");
}
private void dumpInputStack() {
Iterator<String> it = mInputStack.iterator();
StringBuilder sb = new StringBuilder();
while (it.hasNext()) {
CharSequence iValue = it.next();
sb.append(iValue);
}
mStackText.setText(sb.toString());
}
private String evaluateResult(boolean requestedByUser) {
if ((!requestedByUser && mOperationStack.size() != 4)
|| (requestedByUser && mOperationStack.size() != 3))
return null;
String left = mOperationStack.get(0);
String operator = mOperationStack.get(1);
String right = mOperationStack.get(2);
String tmp = null;
if (!requestedByUser)
tmp = mOperationStack.get(3);
double leftVal = Double.parseDouble(left.toString());
double rightVal = Double.parseDouble(right.toString());
double result = Double.NaN;
if (operator.equals(KeypadButton.DIV.getText())) {
result = leftVal / rightVal;
} else if (operator.equals(KeypadButton.MULTIPLY.getText())) {
result = leftVal * rightVal;
} else if (operator.equals(KeypadButton.PLUS.getText())) {
result = leftVal + rightVal;
} else if (operator.equals(KeypadButton.MINUS.getText())) {
result = leftVal - rightVal;
}
String resultStr = doubleToString(result);
if (resultStr == null)
return null;
mOperationStack.clear();
if (!requestedByUser) {
mOperationStack.add(resultStr);
mOperationStack.add(tmp);
}
return resultStr;
}
private String doubleToString(double value) {
if (Double.isNaN(value))
return null;
long longVal = (long) value;
if (longVal == value)
return Long.toString(longVal);
else
return Double.toString(value);
}
private double tryParseUserInput() {
String inputStr = userInputText.getText().toString();
double result = Double.NaN;
try {
result = Double.parseDouble(inputStr);
} catch (NumberFormatException nfe) {
}
return result;
}
private void displayMemoryStat() {
if (Double.isNaN(memoryValue)) {
memoryStatText.setText("");
} else {
memoryStatText.setText("M = " + doubleToString(memoryValue));
}
}
}
ENUM：
package com.pragmatouch.calculator;
public enum KeypadButton {
MC("MC",KeypadButtonCategory.MEMORYBUFFER)
, MR("MR",KeypadButtonCategory.MEMORYBUFFER)
, MS("MS",KeypadButtonCategory.MEMORYBUFFER)
, M_ADD("M+",KeypadButtonCategory.MEMORYBUFFER)
, M_REMOVE("M-",KeypadButtonCategory.MEMORYBUFFER)
, BACKSPACE("<-",KeypadButtonCategory.CLEAR)
, CE("CE",KeypadButtonCategory.CLEAR)
, C("C",KeypadButtonCategory.CLEAR)
, ZERO("0",KeypadButtonCategory.NUMBER)
, ONE("1",KeypadButtonCategory.NUMBER)
, TWO("2",KeypadButtonCategory.NUMBER)
, THREE("3",KeypadButtonCategory.NUMBER)
, FOUR("4",KeypadButtonCategory.NUMBER)
, FIVE("5",KeypadButtonCategory.NUMBER)
, SIX("6",KeypadButtonCategory.NUMBER)
, SEVEN("7",KeypadButtonCategory.NUMBER)
, EIGHT("8",KeypadButtonCategory.NUMBER)
, NINE("9",KeypadButtonCategory.NUMBER)
, PLUS(" + ",KeypadButtonCategory.OPERATOR)
, MINUS(" - ",KeypadButtonCategory.OPERATOR)
, MULTIPLY(" * ",KeypadButtonCategory.OPERATOR)
, DIV(" / ",KeypadButtonCategory.OPERATOR)
, RECIPROC("1/x",KeypadButtonCategory.OTHER)
, DECIMAL_SEP(",",KeypadButtonCategory.OTHER)
, SIGN("±",KeypadButtonCategory.OTHER)
, SQRT("SQRT",KeypadButtonCategory.OTHER)
, PERCENT("%",KeypadButtonCategory.OTHER)
, CALCULATE("=",KeypadButtonCategory.RESULT)
, PRGM("PRGM",KeypadButtonCategory.PRGM)
, DUMMY("",KeypadButtonCategory.DUMMY);
CharSequence mText; // Display Text
KeypadButtonCategory mCategory;
KeypadButton(CharSequence text,KeypadButtonCategory category) {
mText = text;
mCategory = category;
}
public CharSequence getText() {
return mText;
}
}
package com.pragmatouch.calculator;
public enum KeypadButtonCategory {
MEMORYBUFFER
, NUMBER
, OPERATOR
, DUMMY
, CLEAR
, RESULT
, OTHER
, PRGM
}
答案 0 :(得分：1)
我给你一个很好的答案。我最近想在android中创建自己的按钮，但我想以一种简单的方式做到这一点。按照以下步骤操作，几分钟后我就会发布图片。
1）创建一个新的布局。以LinearLayout开头。在其中嵌套FramedLayout和另一个LinearLayout。
2）然后为其添加TextView。这是练习完美的地方。玩弄属性。了解他们的所作所为。如果您有关于如何显示按钮的一般信息，请转到下一步。
3）你要做的是将其作为按钮包含在另一个视图中。您可以使用特定属性使其看起来像一个按钮。
给我几分钟，我会发布一些代码和图片。
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/CBN_LinearLayout"
style="@android:style/Widget.Button"
android:layout_width="match_parent"
android:layout_height="50dp"
android:orientation="vertical" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:id="@+id/CBV_texview1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginRight="10dp"
android:layout_weight="1"
android:gravity="right"
android:text="@string/checkorder"
android:textColor="@color/Black" />
<FrameLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_weight="1" >
<ImageView
android:id="@+id/CBV_imageView1"
android:layout_width="23dp"
android:layout_height="15dp"
android:layout_gravity="center_vertical"
android:contentDescription="@string/redcirclenotify"
android:src="@drawable/rednotify"
android:visibility="visible" />
<TextView
android:id="@+id/CBV_textview2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginLeft="8dp"
android:gravity="left"
android:text="@string/zero"
android:visibility="visible" />
</FrameLayout>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<TextView
android:id="@+id/CBV_textview3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:fadingEdge="horizontal"
android:gravity="center_horizontal"
android:text="@string/blankstring" />
<TextView
android:id="@+id/CBV_textview4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:gravity="center_horizontal"
android:text="@string/blankstring" />
</LinearLayout>
当您将其作为按钮添加到另一个视图时使用：
<include
android:id="@+id/MI_checkorder"
style="android:buttonStyle"
android:layout_width="wrap_content"
android:layout_height="50dp"
android:layout_gravity="bottom"
android:layout_marginTop="5dp"
android:layout_weight="1"
layout="@layout/custombtnview"
android:background="@style/AppTheme"
android:clickable="true"
android:focusable="true" />
这一点的重要部分是将根LinearLayout的样式设置为@android:style/Widget.Button
一旦完成，它将看起来像一个按钮，像按钮一样工作。
以下是最终产品的图片：
Custom Android Button http://i45.tinypic.com/5y9nac.jpg
你问题的另一部分。调整android中标准按钮的大小：
1）几乎所有内容都可以通过XML的使用方式进行控制。这一切都可以在ADK的右侧区域进行控制。这些属性可帮助您控制几乎所有方面。
例如在计算器中......
您连续有4个按钮，因此您想在水平LinearLayout内添加4个按钮。然后，您可以为每个按钮指定权重1，然后将Width设置为FillParent。这将自动调整按钮的大小，使其平均显示在屏幕的宽度上。
我最好自己进行计算或修改现有代码吗？
我永远不会告诉别人重新创建方向盘，但是，如果你不能很好地理解代码以便在他们离开的地方拾取，那么这对你来说可能是一场艰难的挣扎。如果您无法理解提供给您的代码或如何修改代码，那么您最好的选择是将代码实际发布在另一个问题中并且非常具体，并询问我如何更改此特定按钮显示的内容以及单击它的结果将是。这个论坛取决于人们要求问题清晰简洁。如果没有，则问题将在打开时尽快结束。一般化在网站上受到严重谴责。
最后，我要做的是制作自己的科学计算器，但我不想花费额外的时间进行简单的操作。
回答这个问题的最佳方法是查看计算器在GUI或图形布局中的组装方式。尝试更改按钮及其功能。例如，只为学习曲线加上一个减号。
1）寻找, PLUS(" + ",KeypadButtonCategory.OPERATOR)并注意这是一个加号的字符串。将其更改为“T”，看看它是否在应用程序中发生变化。如果是，那么进入代码。在代码中，您会在case CALCULATE:中找到ENUM的=符号，然后在evalResult = evaluateResult(true);内找到if (operator.equals(KeypadButton.DIV.getText())) {
result = leftVal / rightVal;
} else if (operator.equals(KeypadButton.MULTIPLY.getText())) {
result = leftVal * rightVal;
} else if (operator.equals(KeypadButton.PLUS.getText())) {
result = leftVal + rightVal;
} else if (operator.equals(KeypadButton.MINUS.getText())) {
result = leftVal - rightVal;
}
。如果你这样做，你就会到达：
result = leftVal + rightVal;现在您可以将result = leftVal - rightVal;更改为{{1}}，而您刚刚更改了它。所以理解代码需要一些时间，但你必须做一些试验和错误才能理解它。我希望这有助于回答你的问题。