我正在使用android studio为Android编写计算器应用程序。我想用4个按钮输入值和功能。然而，我目前正在做的方式是从按钮上写的文本输入。所以对于我的按钮1/2/3，按下1/2/3会传递给textView。
以下是我的MainActivity：
package com.example.myfirstapp;
import android.media.MediaPlayer;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.MediaController;
import android.widget.TextView;
public class MainActivity extends ActionBarActivity {
private int[] operatorButtons = {R.id.operators};
private int[] numericButtons = {R.id.onetwothree, R.id.fourfivesix, R.id.seveneightninezero};
private boolean lastNumeric, stateError;
private TextView txtScreen;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Find the TextView
this.txtScreen = (TextView) findViewById(R.id.txtScreen);
// Find and set OnClickListener to numeric buttons
setNumericOnClickListener();
// Find and set OnClickListener to operator buttons, equal button and decimal point button
setOperatorOnClickListener();
}
private void setNumericOnClickListener() {
// Create a common OnClickListener
View.OnClickListener listener = new View.OnClickListener() {
@Override
public void onClick(View v) {
// Just append/set the text of clicked button
Button button = (Button) v;
if (stateError) {
// If current state is Error, replace the error message
txtScreen.setText(button.getText());
stateError = false;
} else {
// If not, already there is a valid expression so append to it
txtScreen.append(button.getText());
}
// Set the flag
lastNumeric = true;
}
};
// Assign the listener to all the numeric buttons
for (int id : numericButtons) {
findViewById(id).setOnClickListener(listener);
}
}
private void setOperatorOnClickListener() {
// Create a common OnClickListener for operators
View.OnClickListener listener = new View.OnClickListener() {
@Override
public void onClick(View v) {
// If the current state is Error do not append the operator
// If the last input is number only, append the operator
if (lastNumeric && !stateError) {
Button button = (Button) v;
txtScreen.append(button.getText());
lastNumeric = false;
}
}
};
// Assign the listener to all the operator buttons
for (int id : operatorButtons) {
findViewById(id).setOnClickListener(listener);
}
// Equal button
/*findViewById(R.id.btnEqual).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
onEqual();
}
});*/
}
}
和我的activity_main：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/txtScreen"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:gravity="right|center_vertical"
android:maxLength="16"
android:padding="10dp"
android:textAppearance="?android:attr/textAppearanceLarge"
android:textSize="30sp"
android:typeface="serif" />
<!--<Button-->
<!--android:id="@+id/equal1"-->
<!--android:layout_width="match_parent"-->
<!--android:layout_height="100dp"-->
<!--android:text="="-->
<!--/>-->
<Button
android:id="@+id/equal2"
android:layout_width="match_parent"
android:layout_height="100dp"
android:text="="
android:layout_alignParentBottom="true"
/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="@id/txtScreen"
android:orientation="vertical"
android:layout_above="@id/equal2">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1">
<Button
android:id="@+id/onetwothree"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:text="1/2/3"/>
<Button
android:id="@+id/fourfivesix"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:text="4/5/6"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1">
<Button
android:id="@+id/seveneightninezero"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:text="7/8/9/0"/>
<Button
android:id="@+id/operators"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:text="+-*/"/>
</LinearLayout>
</LinearLayout>
</RelativeLayout>
例如，我可以从第一个按钮获得1,2或3的输入吗？所以在1按下你得到1，2按下给2等。
非常感谢任何关于如何向前推进的建议/想法。
亲切的问候， 本
答案 0 :(得分：1)
您可以使用计时器或延迟变量来检测单击，双击或三击。这个post可能是有意义的。如果时间间隔不是一个因素，您可以只跟踪上次按下的按钮，如果再次按下相同的按钮，则相应地更新文本。
如果您按照方法1进行操作，则按钮onetwothree的点击监听器的代码可能是这样的（我在setNumericOnClickListener()中注释了setOperatorOnClickListener()和mainActivity; { {1}}并添加了以下内容：
onCreate完成MainActivity：
Button onetwothree = (Button) findViewById(R.id.onetwothree);
onetwothree.setOnTouchListener(new View.OnTouchListener() {
Handler handler = new Handler();
int numberOfTaps = 0;
long lastTapTimeMs = 0;
long touchDownMs = 0;
@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touchDownMs = System.currentTimeMillis();
break;
case MotionEvent.ACTION_UP:
handler.removeCallbacksAndMessages(null);
if ((System.currentTimeMillis() - touchDownMs) > ViewConfiguration.getTapTimeout()) {
//it was not a tap
numberOfTaps = 0;
lastTapTimeMs = 0;
break;
}
if (numberOfTaps > 0
&& (System.currentTimeMillis() - lastTapTimeMs) < ViewConfiguration.getDoubleTapTimeout()) {
numberOfTaps += 1;
} else {
numberOfTaps = 1;
}
lastTapTimeMs = System.currentTimeMillis();
if (numberOfTaps == 1) {
handler.postDelayed(new Runnable() {
@Override
public void run() {
if (txtScreen.getText().toString() == "") {
txtScreen.setText("1");
} else txtScreen.append("1");
}
}, ViewConfiguration.getDoubleTapTimeout());
}else if (numberOfTaps == 2) {
handler.postDelayed(new Runnable() {
@Override
public void run() {
if (txtScreen.getText().toString() == "") {
txtScreen.setText("2");
} else txtScreen.append("2");
}
}, ViewConfiguration.getDoubleTapTimeout());
} else if (numberOfTaps == 3) {
if (txtScreen.getText().toString() == "") {
txtScreen.setText("3");
} else txtScreen.append("3");
}
}
return true;
}
});
答案 1 :(得分：0)
您可以在执行某些操作时获取所有数字
(Button) plusBtn = (Button) findViewById(R.id.plusBtn);
plusBtn.setOnClickListener(new OnClickListener(){
@Override
public voidonClick(View v){
number1 = Integer.parseInt(txtScreen.getText().toString());
});
number1是全局int。但我不知道它对你有什么帮助，如果这是一个好方法。您可以找到更好的解决方案，只需记住如何将Text从TextView解析为Integer以进行计算。