英文:
How to use a value from one method to other?
问题
于是我在Android Studio中正在开发一个bmi计算器活动。然后我遇到了一个问题，我从类中为两个不同的TextView获取了两个方法内的变量值。这本不应该成为问题，但一旦我在应用程序中切换到另一个TextView，第一个TextView就会发送一个零值，这就是问题所在。有人知道如何修复吗？谢谢！
在onCreate中给出值的两个方法：
inheight.setOnKeyListener(new View.OnKeyListener() {
@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
height = Double.parseDouble(inheight.getText().toString());
if (KeyEvent.KEYCODE_DEL == keyCode) {
if (inheight.getText().length() != 0)
inheight.setText(inheight.getText().subSequence(0, inheight.getText().length() - 1));
}
return true;
}
});
inweight.setOnKeyListener(new View.OnKeyListener() {
@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
weight = Integer.parseInt(inweight.getText().toString());
if (KeyEvent.KEYCODE_DEL == keyCode) {
if (inweight.getText().length() != 0)
inweight.setText(inweight.getText().subSequence(0, inweight.getText().length() - 1));
}
return true;
}
});
以及我尝试计算的Calculate方法：
public void calculate() {
if (height != 0 && weight != 0) {
// 进行计算
} else {
Toast.makeText(this, "错误：值不能为零！", Toast.LENGTH_LONG).show();
}
}
因此，当我运行它时，总是显示弹出消息 :(。请帮忙！
英文:
So i was developing a bmi calculator activity in android studio. And i ran into a problem where i got a value of two variable inside from two methods for different TextView which was defined in the class. That shouldn't be problem but once i switch to another TextView in app. The first one sends a zero value, which is the problem, Anyone knows how to fix it? Thanks !
The two methods in onCreate which give value:
inheight.setOnKeyListener(new View.OnKeyListener() {
@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
height = Double.parseDouble(inheight.getText().toString());
if(KeyEvent.KEYCODE_DEL== keyCode)
{
if(inheight.getText().length() != 0)
inheight.setText(inheight.getText().subSequence(0,inheight.getText().length()-1));
}
return true;
}
});
inweight.setOnKeyListener(new View.OnKeyListener() {
@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
weight = Integer.parseInt(inweight.getText().toString());
if(KeyEvent.KEYCODE_DEL == keyCode)
{
if(inweight.getText().length() != 0)
inweight.setText(inweight.getText().subSequence(0,inweight.getText().length()-1));
}
return true;
}
});
And the Calculate method where i try to calulate
public void calculate()
{
if(height!=0 && weight !=0)
{
// do this
}
else
{
Toast.makeText(this, "Error: Values Cannot Be Zero!", Toast.LENGTH_LONG).show();
}
So when i run it always shows the toast message :(. Please Help!
答案1
得分: 0
如安卓文档中所述，View.OnKeyListener仅对硬件键盘有效，而软件输入方法（例如安卓使用的方法）无需触发此监听器的义务。
因此，与其使用View.OnKeyListener来获取您的值，我建议尝试不同的方法（例如，在按下按钮后获取值，实现View.OnClickListener）。
另外，您确定仅第一个TextView给您零值，还是两个TextView都是？
英文:
As stated in the android documentation, View.OnKeyListener is useful only for hardware keyboards , and a software input method (like the one android uses), has no obligation to trigger this listener.
So instead of using View.OnKeyListener to get your values i would try a different approach (i.e getting the values after pressing a button, implementing View.OnClickListener )
Also are you sure that only the first TextView gives you the zero value, or both ?
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