Toast的使用
Toast的使用是十分的简单的。
Toast.makeText(this, "Hi!", Toast.LENGTH_SHORT).show();
有时候我们需要Toast的弹出的位置刚好当前控件的位置，那么如何去控制呢？
这个时候涉及到
public void setGravity(int gravity, int xOffset, int yOffset);
下面是界面的代码
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:text="Button" />
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:text="Button" />
<Button
android:id="@+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:text="Button" />
<Button
android:id="@+id/button4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:text="Button" />
</RelativeLayout>
下面是Activity的代码
public class Test7 extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.test7);
Button button1 = (Button) findViewById(R.id.button1);
Button button2 = (Button) findViewById(R.id.button2);
Button button3 = (Button) findViewById(R.id.button3);
Button button4 = (Button) findViewById(R.id.button4);
button1.setOnClickListener(onClickListener);
button2.setOnClickListener(onClickListener);
button3.setOnClickListener(onClickListener);
button4.setOnClickListener(onClickListener);
}
private OnClickListener onClickListener = new OnClickListener() {
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.button1:
Toast toast1 = Toast.makeText(getApplicationContext(),
"Bottom button1!", Toast.LENGTH_SHORT);
toast1.setGravity(Gravity.TOP | Gravity.LEFT, 0, 0);
toast1.show();
break;
case R.id.button2:
Toast toast2 = Toast.makeText(getApplicationContext(),
"Bottom button2!", Toast.LENGTH_SHORT);
toast2.setGravity(Gravity.TOP | Gravity.RIGHT, 0, 0);
toast2.show();
break;
case R.id.button3:
Toast toast3 = Toast.makeText(getApplicationContext(),
"Bottom button3!", Toast.LENGTH_SHORT);
toast3.setGravity(Gravity.BOTTOM | Gravity.LEFT, 0, 0);
toast3.show();
break;
case R.id.button4:
Toast toast4 = Toast.makeText(getApplicationContext(),
"Bottom button4!", Toast.LENGTH_SHORT);
toast4.setGravity(Gravity.BOTTOM | Gravity.RIGHT, 0, 0);
toast4.show();
break;
default:
break;
}
}
};
}
知识点
关键的核心 是 toast.setGravity(Gravity.BOTTOM | Gravity.RIGHT, 0, 0);
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Tag
注重某些类的内部结构，学会查看源码。
