使用自定义对话框接受用户输入,然后使用getter
方法将这些值传递给另一个活动。
但是,当我值传递给该字符串值输出到一个方法CSV
文件shipName
,analystName
等的值显示为这样的文件在空的," "
虽然我已经在对话框中输入的值。
我在调试菜单的表情窗口看着字符串值调试的问题,shipName
和analystName
而值表达式窗口从不更新。
我从中得知输入被传递的方法i不正确。
有谁知道为什么输出的值是空的?
这是使用的对话框类:
package ie.gmi.computing;
import android.annotation.SuppressLint;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.renderscript.Sampler;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MyMessageDialog {
private Context context;
private EditText shipText, scientistNameText , scientistEmailText , volumeText , colourText ;
private String shipString, scientistNameString , scientistEmailString , volumeString , colourString ;
public AlertDialog displayMessage(Context context, String title, String message){
AlertDialog.Builder builder = new AlertDialog.Builder(context);
builder.setTitle(title);
builder.setMessage(message);
LayoutInflater inflater = LayoutInflater.from(context);
final View v = inflater.inflate(R.layout.custom_view, null);
builder.setView(v);
shipText = (EditText)v.findViewById(R.id.shipNameEditText);
scientistNameText = (EditText)v.findViewById(R.id.scientistEditText);
scientistEmailText = (EditText)v.findViewById(R.id.emailEditText);
volumeText = (EditText)v.findViewById(R.id.volumeEditText);
colourText = (EditText)v.findViewById(R.id.colourEditText);
builder.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
});
builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
AlertDialog dialog= builder.create();
dialog.show();
Button tb = dialog.getButton(DialogInterface.BUTTON_POSITIVE);
tb.setOnClickListener(new CustomListener(dialog));
return dialog;
}
//getter/setters to allow access to string values
//in SearchResult class
public EditText getShipText() {
return shipText;
}
public void setShipText(EditText shipText) {
this.shipText = shipText;
}
public EditText getScientistNameText() {
return scientistNameText;
}
public void setScientistNameText(EditText scientistNameText) {
this.scientistNameText = scientistNameText;
}
public EditText getScientistEmailText() {
return scientistEmailText;
}
public void setScientistEmailText(EditText scientistEmailText) {
this.scientistEmailText = scientistEmailText;
}
public String getShipString() {
return shipString;
}
public void setShipString(String shipString) {
this.shipString = shipString;
}
public String getScientistNameString() {
return scientistNameString;
}
public void setScientistNameString(String scientistNameString) {
this.scientistNameString = scientistNameString;
}
public String getScientistEmailString() {
return scientistEmailString;
}
public void setScientistEmailString(String scientistEmailString) {
this.scientistEmailString = scientistEmailString;
}
public String getVolumeString() {
return volumeString;
}
public void setVolumeString(String volumeString) {
this.volumeString = volumeString;
}
public String getColourString() {
return colourString;
}
public void setColourString(String colourString) {
this.colourString = colourString;
}
public EditText getVolumeText() {
return volumeText;
}
public void setVolumeText(EditText volumeText) {
this.volumeText = volumeText;
}
public EditText getColourText() {
return colourText;
}
public void setColourText(EditText colourText) {
this.colourText = colourText;
}
@SuppressLint("NewApi")
class CustomListener implements View.OnClickListener {
private final Dialog dialog;
public CustomListener(Dialog dialog) {
this.dialog = dialog;
}
@SuppressLint("NewApi")
@Override
public void onClick(View v) {
if(shipText.getText().toString().isEmpty() && !shipText.getText().toString().equals(null)){
shipText.setError("The Field is required");
}else if(scientistNameText.getText().toString().isEmpty() && !scientistNameText.getText().toString().equals(null)){
scientistNameText.setError("The Field is required");
}else if(scientistEmailText.getText().toString().isEmpty() && !scientistEmailText.getText().toString().equals(null)){
scientistEmailText.setError("The Field is required");
}else if(volumeText.getText().toString().isEmpty() && !volumeText.getText().toString().equals(null)){
volumeText.setError("The Field is required");
}else if(colourText.getText().toString().isEmpty() && !colourText.getText().toString().equals(null)){
colourText.setError("The Field is required");
}else{
shipText.setError(null);
scientistNameText.setError(null);
scientistEmailText.setError(null);
volumeText.setError(null);
colourText.setError(null);
shipString = shipText.getText().toString();
scientistNameString = scientistNameText.getText().toString();
scientistEmailString = scientistEmailText.getText().toString();
volumeString = volumeText.getText().toString();
colourString = colourText.getText().toString();
Toast.makeText(dialog.getContext(), "The Values you get from : " +
"\n Ship name value: " + shipText.getText().toString() +
"\n Scientist name value: " + scientistNameText.getText().toString() +
"\n email value: " + scientistEmailText.getText().toString() +
"\n sample volume value: " + volumeText.getText().toString() +
"\n sample colour value: " + colourText.getText().toString() , Toast.LENGTH_SHORT).show();
dialog.dismiss();
}
}
}
}
当我选择设置按钮时,这就是我检索SearchResult类中的值的方式:
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_settings:
MyMessageDialog dialog =new MyMessageDialog();
dialog.displayMessage(SearchResult.this, "Sample Info", "Required");
// store / use the values here
shipName = dialog.getShipString();
analystName = dialog.getScientistNameString();
analystEmail = dialog.getScientistEmailString();
sampleVolume = dialog.getVolumeString();
sampleColour = dialog.getColourString();
longitudeValue = String.valueOf(lng);
latitudeValue = String.valueOf(lat);
sampleMaterial = message;
return true;
default:
return super.onOptionsItemSelected(item);
}
}
您显示的对话框是异步的;也就是说,在onOptionsItemSelected()
中的代码执行不会在调用后暂停dialog.displayMessage()
,因此getter会返回这些字段的初始值,在所有情况下均为null。在的onClick()
方法中设置了这些字段之后,您应该创建一个由Activity实现的接口以接收回调CustomListener
,然后更新Activity的变量。
在对话框类中,我们创建一个接口。例如:
public class MyMessageDialog {
public interface DialogCallback {
public void onValuesSet();
}
...
}
确保保存对上下文的引用:
public AlertDialog displayMessage(Context context, String title, String message){
this.context = context;
...
}
在onClick()
方法的最后,设置字段的值之后:
((DialogCallback) context).onValuesSet();
Activity需要实现我们创建的接口,对话框应该是类成员,并且字段将在接口的回调方法中设置:
public class SearchResult extends Activity
implements MyMessageDialog.DialogCallback {
...
MyMessageDialog dialog;
@Override
public void onValuesSet()
{
shipName = dialog.getShipString();
analystName = dialog.getScientistNameString();
...
}
...
}
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