Java 如何在edittext-ContextChanged的情况下显示AlertDialog
我有一个Java 如何在edittext-ContextChanged的情况下显示AlertDialog,java,android,android-alertdialog,textwatcher,Java,Android,Android Alertdialog,Textwatcher,我有一个活动，有几个编辑文本。如果用户单击“Cancel”按钮，并且这些editText中没有任何更改，则应用程序应转到上一个活动，但如果这些editText中有更改，则我希望用户看到警报对话框： Save changes you made? NO YES 我已经为这些editText设置了TextWatcher，例如： //let's set up a textwatcher so if the state of any of the edittexts has chang
活动编辑文本CanceleditTexteditText警报对话框Save changes you made?
NO YES
editTextTextWatcher //let's set up a textwatcher so if the state of any of the edittexts has changed.
//if it has changed and user clicks 'CANCEL', we'll ask first, '
//You've made changes here. Sure you want to cancel?'
TextWatcher edittw = new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
@Override
public void afterTextChanged(Editable s) {
Toast.makeText(EditContact.this, "change detected", Toast.LENGTH_SHORT).show();
}
};
categoryname.addTextChangedListener(edittw);
namename.addTextChangedListener(edittw);
phonename.addTextChangedListener(edittw);
addressname.addTextChangedListener(edittw);
commentname.addTextChangedListener(edittw);
警报对话框取消编辑文本编辑文本AlerDialogprivate void cancelButton() {
cancel.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
//add a dialogue box
AlertDialog.Builder builder = new AlertDialog.Builder(view.getContext());
builder.setMessage("Save changes you made?").setPositiveButton("Yes", dialogClickListener)
.setNegativeButton("No", dialogClickListener).show();
}
});
}
//Are you sure you want to cancel? dialogue
DialogInterface.OnClickListener dialogClickListener = new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
switch (which){
case DialogInterface.BUTTON_POSITIVE:
//Yes button clicked
pDialog = new ProgressDialog(EditContact.this);
// Showing progress dialog for the review being saved
pDialog.setMessage("Saving...");
pDialog.show();
//post the review_id in the current activity to EditContact.php and
StringRequest stringRequest = new StringRequest(Request.Method.POST, EditContact_URL,
new Response.Listener<String>() {
@Override
public void onResponse(String response) {
//hide the dialogue saying 'Saving...' when page is saved
pDialog.dismiss();
Toast.makeText(EditContact.this, response, Toast.LENGTH_LONG).show();
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(EditContact.this, "problem here", Toast.LENGTH_LONG).show();
}
}) {
@Override
protected Map<String, String> getParams() {
Map<String, String> params = new HashMap<String, String>();
//we are posting review_id into our EditContact.php file,
//the second value, review_id,
// is the value we get from Android.
// When we see this in our php, $_POST["review_id"],
//put in the value from Android
params.put("review_id", review_id);
return params;
}
};
AppController.getInstance().addToRequestQueue(stringRequest);
//when cancelled, back to the PopulistoListView class
Intent j = new Intent(EditContact.this,PopulistoListView.class);
startActivity(j);
break;
case DialogInterface.BUTTON_NEGATIVE:
//close the activity
finish();
}
}
};
private void cancelButton（）{
cancel.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图）{
//添加一个对话框
AlertDialog.Builder=新建AlertDialog.Builder（view.getContext（））；
setMessage（“保存所做的更改？”）。setPositiveButton（“是”，对话框ClickListener）
.setNegativeButton（“否”，对话框ClickListener）.show（）；
}
});
}
//你确定要取消吗？对话
DialogInterface.OnClickListener dialogClickListener=新建DialogInterface.OnClickListener（）{
@凌驾
public void onClick（DialogInterface dialog，int which）{
开关（哪个）{
case DialogInterface.BUTTON_阳性：
//单击“是”按钮
pDialog=newprogressdialog（EditContact.this）；
//显示正在保存的审阅的进度对话框
pDialog.setMessage（“保存…”）；
pDialog.show（）；
//将当前活动中的review_id发布到EditContact.php并
StringRequest StringRequest=新的StringRequest（Request.Method.POST，EditContact\u URL，
新的Response.Listener（）{
@凌驾
公共void onResponse（字符串响应）{
//保存页面时隐藏“正在保存…”对话框
pDialog.disclose（）；
Toast.makeText（EditContact.this，response，Toast.LENGTH_LONG.show（）；
}
},
新的Response.ErrorListener（）{
@凌驾
公共无效onErrorResponse（截击错误）{
Toast.makeText（EditContact.this，“这里有问题”，Toast.LENGTH_LONG.show（）；
}
}) {
@凌驾
受保护的映射getParams（）{
Map params=新的HashMap（）；
//我们正在将review_id发布到EditContact.php文件中，
//第二个值，review_id，
//是我们从Android获得的价值。
//当我们在php中看到这一点时，$\u POST[“review\u id”]，
//输入来自Android的值
参数put（“审查id”，审查id）；
返回参数；
}
};
AppController.getInstance（）.addToRequestQueue（stringRequest）；
//取消后，返回到PopulatoListView类
Intent j=新的Intent（EditContact.this，PopulistoListView.class）；
星触觉（j）；
打破
案例对话框界面按钮\否：
//关闭活动
完成（）；
}
}
};
我在互联网上搜索了一些教程或帖子，其中有“TextWatcher”和“AlertDialog”之类的短语，但我没有找到任何可以帮助我实现目标的内容。尝试添加AlertDialog，如下图所示，您可以将对话框放在AfterChange方法中：
TextWatcher edittw=new TextWatcher（）{
@凌驾
更改前文本之前的公共void（字符序列s、int start、int count、int after）{
}
@凌驾
public void onTextChanged（字符序列、int start、int before、int count）{
}
@凌驾
公共无效后文本已更改（可编辑）{
Toast.makeText（EditContact.this，“检测到更改”，Toast.LENGTH_SHORT.show（）；
AlertDialog.Builder；
if（Build.VERSION.SDK\u INT>=Build.VERSION\u code.LOLLIPOP）{
builder=newalertdialog.builder（getApplicationContext（），android.R.style.Theme\u Material\u Dialog\u Alert）；
}否则{
builder=新建AlertDialog.builder（getApplicationContext（））；
}
builder.setTitle（“删除条目”）
.setMessage（“确实要删除此条目吗？”）
.setPositiveButton（android.R.string.yes，新的DialogInterface.OnClickListener（）{
public void onClick（DialogInterface dialog，int which）{
//你想要是吗
}
})
.setNegativeButton（android.R.string.no，新的DialogInterface.OnClickListener（）{
public void onClick（DialogInterface dialog，int which）{
//你不想要吗
}
})
.setIcon（android.R
//onCancel Clicked
if(somethingChanged)//compare old values with new values
showDialog();
else
onBackPressed();
boolean isDirty;
TextWatcher edittw = new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
@Override
public void afterTextChanged(Editable s) {
Toast.makeText(EditContact.this, "change detected", Toast.LENGTH_SHORT).show();
isDirty = true;
}
};
categoryname.addTextChangedListener(edittw);
namename.addTextChangedListener(edittw);
phonename.addTextChangedListener(edittw);
addressname.addTextChangedListener(edittw);
commentname.addTextChangedListener(edittw);
private void cancelButton() {
cancel.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(isDirty) {
//add a dialogue box
AlertDialog.Builder builder = new AlertDialog.Builder(view.getContext());
builder.setMessage("Save changes you made?").setPositiveButton("Yes", dialogClickListener)
.setNegativeButton("No", dialogClickListener).show();
}
else {
// this will finish the current activity and the last activity will be popped from the stack.
finish();
}
}
});
}
@Override
onClick(View v) {
if(!(categoryname.getText().toString().isEmpty() && namename.getText().toString().isEmpty() && phonename.getText().toString().isEmpty() && addressname.getText().toString().isEmpty() && commentname.getText().toString().isEmpty())) {
// show your dialog
}
else {
// normal cancel
}
private void cancelButton() {
cancel.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(changed){
AlertDialog.Builder builder = new AlertDialog.Builder(view.getContext());
builder.setMessage("Save changes you made?").setPositiveButton("Yes", dialogClickListener)
.setNegativeButton("No", dialogClickListener).show();
}else {
Log.v(TAG,"nothing changed ");
}
}
});
}