如何在 Android 中动态添加按钮？

如何在 Android 中动态添加按钮？

223587 次浏览
小开 
Button myButton = new Button(this);
myButton.setText("Push Me");


LinearLayout ll = (LinearLayout)findViewById(R.id.buttonlayout);
LayoutParams lp = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
ll.addView(myButton, lp);

看看 这个的例子

小开

试试这个:

LinearLayout ll = (LinearLayout)findViewById(R.id.layout);


Button btn = new Button(this);
btn.setText("Manual Add");
btn.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));
ll.addView(btn);
小开

实际上，我向 xml 布局文件中添加了任何可以使用的内容！然后从特定 Activity 的源代码中通过 id 获取对象，并使用可见性方法“播放”。

这里有一个例子:

((Spinner)findViewById(R.id.email_spinner)).setVisibility(View.GONE);

小开

试试这个代码

 Button btn=new Button(this);
btn.setId(btn);
btn.setBackgroundResource(R.drawable.image);
btn.setMinimumHeight(150);
btn.setMinimumWidth(150);
Relativelayout.addView(btn);
小开

试试这个:

for (int i = 1; i <= 20; i++) {
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
Button btn = new Button(this);
btn.setId(i);
final int id_ = btn.getId();
btn.setText("button " + id_);
btn.setBackgroundColor(Color.rgb(70, 80, 90));
linear.addView(btn, params);
btn1 = ((Button) findViewById(id_));
btn1.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Toast.makeText(view.getContext(),
"Button clicked index = " + id_, Toast.LENGTH_SHORT)
.show();
}
});
}
小开

我使用这个(或非常类似的)代码向 LinearLayout 添加了几个 TextView:

// Quick & dirty pre-made list of text labels...
String names[] = {"alpha", "beta", "gamma", "delta", "epsilon"};
int namesLength = 5;


// Create a LayoutParams...
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.FILL_PARENT);


// Get existing UI containers...
LinearLayout nameButtons = (LinearLayout) view.findViewById(R.id.name_buttons);
TextView label = (TextView) view.findViewById(R.id.master_label);


TextView tv;


for (int i = 0; i < namesLength; i++) {
// Grab the name for this "button"
final String name = names[i];


tv = new TextView(context);
tv.setText(name);


// TextViews CAN have OnClickListeners
tv.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
label.setText("Clicked button for " + name);
}
});


nameButtons.addView(tv, params);
}

这段代码与 dicklaw795的主要区别在于，它不会为每个 TextView 设置()并重新获取() ID ——我发现这是不必要的，尽管我可能需要它在以后的一个常见处理程序例程中识别每个按钮(例如，每个 TextView 都有一个由 onClick ()调用的按钮)。

小开

试着按照代码操作。

LinearLayout layout = (LinearLayout) findViewById(R.id.llayout);
layout.setOrientation(LinearLayout.VERTICAL);


Button btn = new Button(this);
btn.setText("Button1");


layout.add(btn);


btn = new Button(this);
btn.setText(Button2);
layout.add(btn);

像这样，你按照你的要求添加按钮。

小开

试试这个

private void createLayoutDynamically(int n) {


for (int i = 0; i < n; i++) {
Button myButton = new Button(this);
myButton.setText("Button :"+i);
myButton.setId(i);
final int id_ = myButton.getId();


LinearLayout layout = (LinearLayout) findViewById(R.id.myDynamicLayout);
layout.addView(myButton);


myButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Toast.makeText(DynamicLayout.this,
"Button clicked index = " + id_, Toast.LENGTH_SHORT)
.show();
}
});
}
小开

试试这个代码。它会工作的罚款. 。

public class DynamicViewsActivity extends Activity {


Button button;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//setContentView(R.layout.activity_dynamic_views);
ScrollView scrl=new ScrollView(this);
final LinearLayout ll=new LinearLayout(this);
ll.setOrientation(LinearLayout.HORIZONTAL);
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
layoutParams.setMargins(100, 500, 100, 200);
scrl.addView(ll);
Button add_btn=new Button(this);
add_btn.setText("Click Here");


ll.addView(add_btn, layoutParams);




final Context context = this;


add_btn.setOnClickListener(new OnClickListener() {


@Override
public void onClick(View v) {
// TODO Auto-generated method stub


Intent intent = new Intent(context, App2Activity.class);
startActivity(intent);
}
});
this.setContentView(scrl);
}
}
小开 
for (int k = 1; k < 100; k++) {
TableRow row = new TableRow(this);


innerloop:
for (int l = 1; l < 4; l++) {
btn = new Button(this);
TableRow.LayoutParams tr = new TableRow.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
layout.setWeightSum(12.0f);
tr.weight = 0;
btn.setLayoutParams(tr);
btn.setTextColor(a);
btn.setHeight(150);


btn.setWidth(150);
btn.setId(idb);
btn.setText("Button " + idb);
row.addView(btn);
}
}
小开 
Button myButton = new Button(this);
myButton.setId(123);
myButton.setText("Push Me");




LinearLayout ll = (LinearLayout)findViewById(R.id.buttonlayout);
LayoutParams lp = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
ll.addView(myButton, lp);
myButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Toast.makeText(DynamicLayout.this,
"Button clicked index = " + id_, Toast.LENGTH_SHORT)
.show();
}
});
小开

如果你想动态添加按钮，试试这个:

public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
for (int i = 1; i <= 5; i++) {
LinearLayout layout = (LinearLayout) findViewById(R.id.myLinearLayout);
layout.setOrientation(LinearLayout.VERTICAL);
Button btn = new Button(this);
btn.setText("    ");
layout.addView(btn);
}


}
小开 
public void add_btn() {


lin_btn.setWeightSum(3f);
for (int j = 0; j < 3; j++) {
LinearLayout.LayoutParams params1 = new LinearLayout.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
params1.setMargins(10, 0, 0, 10);
params1.weight = 1.0f;


LinearLayout ll;
ll = new LinearLayout(this);
ll.setGravity(Gravity.CENTER_VERTICAL);
ll.setOrientation(LinearLayout.HORIZONTAL);
ll.setLayoutParams(params1);


final Button btn;
btn = new Button(DynamicActivity.this);


btn.setText("A"+(j+1));
btn.setTextSize(15);
btn.setId(j);
btn.setPadding(10, 8, 10, 10);


ll.addView(btn);


lin_btn.addView(ll);




btn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {


if(v.getId()==0)
{
txt_text.setText("Hii");
}else if(v.getId()==1)
{
txt_text.setText("hello");
}else if(v.getId()==2)
{
txt_text.setText("how r u");
}






}
});
}


}
小开

在 mainactivity.xml中写道:

<Button
android:id="@+id/search"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Search"
android:visibility="invisible"/>

在 main.java中写道:

Button buttonSearch;
buttonSearch = (Button)findViewById(R.id.search);
buttonSearch.setVisibility(View.VISIBLE);
小开

看看这个。

LinearLayout ll_Main  = new LinearLayout(getActivity());
LinearLayout ll_Row01 = new LinearLayout(getActivity());
LinearLayout ll_Row02 = new LinearLayout(getActivity());


ll_Main.setOrientation(LinearLayout.VERTICAL);
ll_Row01.setOrientation(LinearLayout.HORIZONTAL);
ll_Row02.setOrientation(LinearLayout.HORIZONTAL);


final Button button01    = new Button(getActivity());
final Button button02    = new Button(getActivity());
final Button button03    = new Button(getActivity());
final Button button04    = new Button(getActivity());


ll_Row01.addView(button01);
ll_Row01.addView(button02);


ll_Row02.addView(button03);
ll_Row02.addView(button04);


ll_Main.addView(ll_Row01);
ll_Main.addView(ll_Row02);


button04.setVisibility(View.INVISIBLE);
button04.setVisibility(View.VISIBLE);
小开

你可以为你的按钮创建一个基本的布局，并且只动态地改变特定的内容，就像我做的这个项目是为了运行材料设计课程中的不同练习:

在本例中，我使用了一个预配置的 AppCompatButton:

layout_base_button.xml

<android.support.v7.widget.AppCompatButton
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/btn_base"
android:layout_width="200dp"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginTop="8dp"
style="@style/RaisedButton"
>


</android.support.v7.widget.AppCompatButton>




<style name="RaisedButton" parent="Widget.AppCompat.Button.Colored">
<item name="android:textSize">11sp</item>
<item name="android:textStyle">bold</item>
</style>

在 MainActivity中，我创建了一些实例并修改了我需要的东西，比如按钮文本和 onClick 事件:

<ScrollView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="udemy.android.materialdesign.MainActivity">


<LinearLayout
android:id="@+id/base_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
>


</LinearLayout>




</ScrollView>






public class MainActivity extends AppCompatActivity {




@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
LinearLayout baseLayout = findViewById(R.id.base_layout);


baseLayout.addView(createButton("TextFields", baseLayout,
view -> startActivity(createIntent(TextFieldsActivity.class))
));


baseLayout.addView(createButton("Buttons", baseLayout,
view -> startActivity(createIntent(ButtonsActivity.class))
));


baseLayout.addView(createButton("Toolbar", baseLayout,
view -> startActivity(createIntent(ToolbarActivity.class))
));


}


private View createButton(String text, LinearLayout baseLayout, View.OnClickListener onClickEvent) {
View inflated = LayoutInflater.from(this).inflate(R.layout.layout_base_button, baseLayout, false);
AppCompatButton btnBase = inflated.findViewById(R.id.btn_base);


btnBase.setText(text);
btnBase.setOnClickListener(onClickEvent);
return btnBase;
}


private Intent createIntent(Class<?> cls) {
return new Intent(this, cls);
}
}

抱歉我迟到了。

小开 
Button btn = new Button(this);
btn.setText("Submit");
LinearLayout linearLayout = (LinearLayout)findViewById(R.id.buttonlayout);
LayoutParams buttonlayout = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
linearLayout.addView(btn, buttonlayout);
小开

我需要更加动态地创建按钮，不仅仅是在运行时，而是通过按下另一个按钮。所以点击这个按钮会动态地在它下面创建更多的按钮。我建议在活动上使用 ScrollView 或者限制点击次数——这样就不会有按钮离开屏幕。

Activity _ main. xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">


<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:layout_editor_absoluteY="675dp">


<LinearLayout
android:id="@+id/layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">


<Button
android:id="@+id/newItemButton"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Button1" />


</LinearLayout>
</ScrollView>
</androidx.constraintlayout.widget.ConstraintLayout>

MainActivity.java

public class MainActivity extends AppCompatActivity {


@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);


LinearLayout ll = (LinearLayout)findViewById(R.id.layout); //Screen layout
LinearLayout.LayoutParams params = new
LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT);


final Button newItemButton = findViewById(R.id.newItemButton);
newItemButton.setText("Create new button");


newItemButton.setOnClickListener(new View.OnClickListener() {
int pressCount = 1; //Count how many times button was pressed
public void onClick(View v) {


newItemButton.setText("Button Clicked: "+pressCount);
createButton(pressCount, params, ll); //Click to create new button
pressCount++;
}
});




} //end of onCreate


public void createButton(int id, LinearLayout.LayoutParams inputParams, LinearLayout inputLL) {
Button outButton = new Button(this);
outButton.setId(id);
final int id_ = outButton.getId();
outButton.setText("Button " + id_);
inputLL.addView(outButton, inputParams);
}


}//end of AppCompatActivity

这会给你一个带按钮的活动。 当您单击该按钮时，将在其下面生成一个新按钮。 如果您产生的数量太多以至于不能在屏幕上显示，scrollView 会处理这个问题。


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