[英]Android Button not working?
我想創建一個以英尺和英尺為單位輸入的應用程序,以及每英尺的成本,並計算桿的成本。 這是一個非常簡單的應用程序,我完成了大部分工作,但當我點擊計算Button
,代替“結果”時,我的回答應該來了。
現在這里是XML代碼:
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="@string/ft"
android:id="@+id/feet"
android:layout_marginTop="41dp"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<EditText
android:layout_width="100dp"
android:layout_height="wrap_content"
android:id="@+id/feet1"
android:layout_alignBottom="@+id/feet"
android:layout_toRightOf="@+id/feet"
android:inputType="text" />
<EditText
android:layout_width="100dp"
android:layout_height="wrap_content"
android:id="@+id/inches"
android:layout_alignBottom="@+id/feet"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:inputType="text" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="@string/in"
android:id="@+id/Inches"
android:layout_alignBottom="@+id/feet"
android:layout_toLeftOf="@+id/inches"
android:layout_toStartOf="@+id/inches" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="@string/cost"
android:id="@+id/cost"
android:layout_marginTop="60dp"
android:layout_below="@+id/feet"
android:layout_toRightOf="@+id/feet"
android:layout_toEndOf="@+id/feet" />
<EditText
android:layout_width="100dp"
android:layout_height="wrap_content"
android:id="@+id/calcost"
android:layout_alignBottom="@+id/cost"
android:layout_toRightOf="@+id/cost"
android:layout_toEndOf="@+id/cost"
android:inputType="text" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/cal"
android:id="@+id/calculate"
android:layout_below="@+id/cost"
android:layout_centerHorizontal="true"
android:layout_marginTop="73dp" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="@string/ans"
android:id="@+id/result"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="123dp" />
這是Java代碼:
package com.example.baqir.saecost;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RelativeLayout;
import android.widget.TextView;
public class MainActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void add(View v)
{
RelativeLayout rel= (RelativeLayout) findViewById(R.id.rel);
final TextView result= (TextView)findViewById(R.id.result);
EditText et1= (EditText)findViewById(R.id.feet1);
EditText et2= (EditText) findViewById(R.id.inches);
EditText ct= (EditText)findViewById(R.id.calcost);
final double a=Double.parseDouble(String.valueOf(et1.getText()));
final double b=Double.parseDouble(String.valueOf(et2.getText()));
final double c=Double.parseDouble(String.valueOf(ct.getText()));
final Button button = (Button) findViewById(R.id.calculate);
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View g) {
double i;
i=(a+(b/12))*c;
result.setText(i+" Rs");
}
});
}
@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);
}
}
像這樣更改你的代碼:
public void add(View v)
{
RelativeLayout rel= (RelativeLayout) findViewById(R.id.rel);
final TextView result= (TextView)findViewById(R.id.result);
EditText et1= (EditText)findViewById(R.id.feet1);
EditText et2= (EditText) findViewById(R.id.inches);
EditText ct= (EditText)findViewById(R.id.calcost);
final double a=Double.parseDouble(String.valueOf(et1.getText()));
final double b=Double.parseDouble(String.valueOf(et2.getText()));
final double c=Double.parseDouble(String.valueOf(ct.getText()));
final Button button = (Button) findViewById(R.id.calculate);
// button.setOnClickListener(new View.OnClickListener() {
// public void onClick(View g) {
double i;
i=(a+(b/12))*c;
result.setText(i+" Rs");
// }
// });
}
並在您的XML更改中添加onClick
,如下所示:
<Button
android:onClick="add"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/cal"
android:id="@+id/calculate"
android:layout_below="@+id/cost"
android:layout_centerHorizontal="true"
android:layout_marginTop="73dp" />
我知道你的問題只是在你的Button
所在的XML布局中添加這一行
android:onClick="add"
public class MainActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
RelativeLayout rel= (RelativeLayout) findViewById(R.id.rel);
final TextView result= (TextView)findViewById(R.id.result);
EditText et1= (EditText)findViewById(R.id.feet1);
EditText et2= (EditText) findViewById(R.id.inches);
EditText ct= (EditText)findViewById(R.id.calcost);
final double a=Double.parseDouble(String.valueOf(et1.getText()));
final double b=Double.parseDouble(String.valueOf(et2.getText()));
final double c=Double.parseDouble(String.valueOf(ct.getText()));
final Button button = (Button) findViewById(R.id.calculate);
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View g) {
double i;
i=(a+(b/12))*c;
result.setText(i+" Rs");
}
});
}
}
刪除方法並在oncreate方法中編寫代碼。
package com.example.baqir.saecost;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RelativeLayout;
import android.widget.TextView;
public class MainActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
RelativeLayout rel= (RelativeLayout) findViewById(R.id.rel);
final TextView result= (TextView)findViewById(R.id.result);
EditText et1= (EditText)findViewById(R.id.feet1);
EditText et2= (EditText) findViewById(R.id.inches);
EditText ct= (EditText)findViewById(R.id.calcost);
final Button button = (Button) findViewById(R.id.calculate);
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View g) {
double i;
final double a=Double.parseDouble(String.valueOf(et1.getText()));
final double b=Double.parseDouble(String.valueOf(et2.getText()));
final double c=Double.parseDouble(String.valueOf(ct.getText()));
i=(a+(b/12))*c;
result.setText(i+" Rs");
}
});
}
@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);
}
}
只要XML文件沒問題(ID是您實際使用的ID,沒有混淆或任何東西),這應該可以解決您的問題。
在按下按鈕之前你正在從editTexts中獲取值...所以實際上,在你寫了任何東西之后,抓取值的代碼已經被執行了。
在oncreate方法中初始化所有視圖它應該工作
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