是的,我知道有AlertDialog。但我很惊讶地知道在Android中显示对话框有多么困难(好吧,至少不是程序员友好的)。
我曾经是一名。net开发人员,我想知道在android上是否有类似的功能?
if (MessageBox.Show("Sure?", "", MessageBoxButtons.YesNo) == DialogResult.Yes){
// Do something...
}
是的,我知道有AlertDialog。但我很惊讶地知道在Android中显示对话框有多么困难(好吧,至少不是程序员友好的)。
我曾经是一名。net开发人员,我想知道在android上是否有类似的功能?
if (MessageBox.Show("Sure?", "", MessageBoxButtons.YesNo) == DialogResult.Yes){
// Do something...
}
当前回答
Kotlin在Android::
override fun onBackPressed() {
confirmToCancel()
}
private fun confirmToCancel() {
AlertDialog.Builder(this)
.setTitle("Title")
.setMessage("Do you want to cancel?")
.setCancelable(false)
.setPositiveButton("Yes") {
dialog: DialogInterface, _: Int ->
dialog.dismiss()
// for sending data to previous activity use
// setResult(response code, data)
finish()
}
.setNegativeButton("No") {
dialog: DialogInterface, _: Int ->
dialog.dismiss()
}
.show()
}
其他回答
Kotlin在Android::
override fun onBackPressed() {
confirmToCancel()
}
private fun confirmToCancel() {
AlertDialog.Builder(this)
.setTitle("Title")
.setMessage("Do you want to cancel?")
.setCancelable(false)
.setPositiveButton("Yes") {
dialog: DialogInterface, _: Int ->
dialog.dismiss()
// for sending data to previous activity use
// setResult(response code, data)
finish()
}
.setNegativeButton("No") {
dialog: DialogInterface, _: Int ->
dialog.dismiss()
}
.show()
}
这里所有的答案都归结为冗长且不利于读者的代码:这正是提问者试图避免的。对我来说,最简单的方法是在这里使用lambdas:
new AlertDialog.Builder(this)
.setTitle("Are you sure?")
.setMessage("If you go back you will loose any changes.")
.setPositiveButton("Yes", (dialog, which) -> {
doSomething();
dialog.dismiss();
})
.setNegativeButton("No", (dialog, which) -> dialog.dismiss())
.show();
Android中的Lambdas需要retrolambda插件(https://github.com/evant/gradle-retrolambda),但无论如何,它对编写更清晰的代码非常有帮助。
谢谢尼基,你的回答帮助我改善了现有的简单添加我想要的行动如下
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Do this action");
builder.setMessage("do you want confirm this action?");
builder.setPositiveButton("YES", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// Do do my action here
dialog.dismiss();
}
});
builder.setNegativeButton("NO", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// I do not need any action here you might
dialog.dismiss();
}
});
AlertDialog alert = builder.create();
alert.show();
你可以为决策实现一个通用的解决方案,并在另一种情况下使用,而不仅仅是yes/no和自定义警报动画或布局:
像这样的东西;首先创建用于传输数据的类:
public class AlertDecision {
private String question = "";
private String strNegative = "";
private String strPositive = "";
public AlertDecision question(@NonNull String question) {
this.question = question;
return this;
}
public AlertDecision ansPositive(@NonNull String strPositive) {
this.strPositive = strPositive;
return this;
}
public AlertDecision ansNegative(@NonNull String strNegative) {
this.strNegative = strNegative;
return this;
}
public String getQuestion() {
return question;
}
public String getAnswerNegative() {
return strNegative;
}
public String getAnswerPositive() {
return strPositive;
}
}
后的接口,用于返回结果
public interface OnAlertDecisionClickListener {
/**
* Interface definition for a callback to be invoked when a view is clicked.
*
* @param dialog the dialog that was clicked
* @param object The object in the position of the view
*/
void onPositiveDecisionClick(DialogInterface dialog, Object object);
void onNegativeDecisionClick(DialogInterface dialog, Object object);
}
现在你可以很容易地创建一个utils(在这个类中,你可以为警报实现不同的动画或自定义布局):
public class AlertViewUtils {
public static void showAlertDecision(Context context,
@NonNull AlertDecision decision,
final OnAlertDecisionClickListener listener,
final Object object) {
AlertDialog.Builder builder = new AlertDialog.Builder(context);
builder.setMessage(decision.getQuestion());
builder.setPositiveButton(decision.getAnswerPositive(),
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
listener.onPositiveDecisionClick(dialog, object);
}
});
builder.setNegativeButton(decision.getAnswerNegative(),
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
listener.onNegativeDecisionClick(dialog, object);
}
});
android.support.v7.app.AlertDialog dialog = builder.create();
dialog.show();
}
}
最后是活动或片段的召唤;你可以在你的案例或其他任务中使用这个:
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity);
initResources();
}
public void initResources() {
Button doSomething = (Button) findViewById(R.id.btn);
doSomething.setOnClickListener(getDecisionListener());
}
private View.OnClickListener getDecisionListener() {
return new View.OnClickListener() {
@Override
public void onClick(View v) {
AlertDecision decision = new AlertDecision()
.question("question ...")
.ansNegative("negative action...")
.ansPositive("positive action... ");
AlertViewUtils.showAlertDecision(MainActivity.this,
decision, getOnDecisionListener(), v);
}
};
}
private OnAlertDecisionClickListener getOnDecisionListener() {
return new OnAlertDecisionClickListener() {
@Override
public void onPositiveDecisionClick(DialogInterface dialog, Object object) {
//do something like create, show views, etc...
}
@Override
public void onNegativeDecisionClick(DialogInterface dialog, Object object) {
//do something like delete, close session, etc ...
}
};
}
}
芬兰湾的科特林的实现。
你可以像这样创建一个简单的函数:
fun dialogYesOrNo(
activity: Activity,
title: String,
message: String,
listener: DialogInterface.OnClickListener
) {
val builder = AlertDialog.Builder(activity)
builder.setPositiveButton("Yes", DialogInterface.OnClickListener { dialog, id ->
dialog.dismiss()
listener.onClick(dialog, id)
})
builder.setNegativeButton("No", null)
val alert = builder.create()
alert.setTitle(title)
alert.setMessage(message)
alert.show()
}
像这样叫它:
dialogYesOrNo(
this,
"Question",
"Would you like to eat?",
DialogInterface.OnClickListener { dialog, id ->
// do whatever you need to do when user presses "Yes"
}
})